use log::debug;
use super::ast::*;
use super::dialect::keywords;
use super::dialect::keywords::Keyword;
use super::dialect::Dialect;
use super::tokenizer::*;
use std::error::Error;
use std::fmt;
#[derive(Debug, Clone, PartialEq)]
pub enum ParserError {
TokenizerError(String),
ParserError(String),
}
macro_rules! parser_err {
($MSG:expr) => {
Err(ParserError::ParserError($MSG.to_string()))
};
}
macro_rules! return_ok_if_some {
($e:expr) => {{
if let Some(v) = $e {
return Ok(v);
}
}};
}
#[derive(PartialEq)]
pub enum IsOptional {
Optional,
Mandatory,
}
use IsOptional::*;
pub enum IsLateral {
Lateral,
NotLateral,
}
use crate::ast::Statement::CreateVirtualTable;
use IsLateral::*;
impl From<TokenizerError> for ParserError {
fn from(e: TokenizerError) -> Self {
ParserError::TokenizerError(format!(
"{} at Line: {}, Column {}",
e.message, e.line, e.col
))
}
}
impl fmt::Display for ParserError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(
f,
"sql parser error: {}",
match self {
ParserError::TokenizerError(s) => s,
ParserError::ParserError(s) => s,
}
)
}
}
impl Error for ParserError {}
pub struct Parser {
tokens: Vec<Token>,
index: usize,
}
impl Parser {
pub fn new(tokens: Vec<Token>) -> Self {
Parser { tokens, index: 0 }
}
pub fn parse_sql(dialect: &dyn Dialect, sql: &str) -> Result<Vec<Statement>, ParserError> {
let mut tokenizer = Tokenizer::new(dialect, &sql);
let tokens = tokenizer.tokenize()?;
let mut parser = Parser::new(tokens);
let mut stmts = Vec::new();
let mut expecting_statement_delimiter = false;
debug!("Parsing sql '{}'...", sql);
loop {
while parser.consume_token(&Token::SemiColon) {
expecting_statement_delimiter = false;
}
if parser.peek_token() == Token::EOF {
break;
}
if expecting_statement_delimiter {
return parser.expected("end of statement", parser.peek_token());
}
let statement = parser.parse_statement()?;
stmts.push(statement);
expecting_statement_delimiter = true;
}
Ok(stmts)
}
pub fn parse_statement(&mut self) -> Result<Statement, ParserError> {
match self.next_token() {
Token::Word(w) => match w.keyword {
Keyword::SELECT | Keyword::WITH | Keyword::VALUES => {
self.prev_token();
Ok(Statement::Query(Box::new(self.parse_query()?)))
}
Keyword::CREATE => Ok(self.parse_create()?),
Keyword::DROP => Ok(self.parse_drop()?),
Keyword::DELETE => Ok(self.parse_delete()?),
Keyword::INSERT => Ok(self.parse_insert()?),
Keyword::UPDATE => Ok(self.parse_update()?),
Keyword::ALTER => Ok(self.parse_alter()?),
Keyword::COPY => Ok(self.parse_copy()?),
Keyword::SET => Ok(self.parse_set()?),
Keyword::SHOW => Ok(self.parse_show()?),
Keyword::START => Ok(self.parse_start_transaction()?),
Keyword::BEGIN => Ok(self.parse_begin()?),
Keyword::COMMIT => Ok(self.parse_commit()?),
Keyword::ROLLBACK => Ok(self.parse_rollback()?),
Keyword::ASSERT => Ok(self.parse_assert()?),
_ => self.expected("an SQL statement", Token::Word(w)),
},
Token::LParen => {
self.prev_token();
Ok(Statement::Query(Box::new(self.parse_query()?)))
}
unexpected => self.expected("an SQL statement", unexpected),
}
}
pub fn parse_expr(&mut self) -> Result<Expr, ParserError> {
self.parse_subexpr(0)
}
pub fn parse_subexpr(&mut self, precedence: u8) -> Result<Expr, ParserError> {
debug!("parsing expr");
let mut expr = self.parse_prefix()?;
debug!("prefix: {:?}", expr);
loop {
let next_precedence = self.get_next_precedence()?;
debug!("next precedence: {:?}", next_precedence);
if precedence >= next_precedence {
break;
}
expr = self.parse_infix(expr, next_precedence)?;
}
Ok(expr)
}
pub fn parse_assert(&mut self) -> Result<Statement, ParserError> {
let condition = self.parse_expr()?;
let message = if self.parse_keyword(Keyword::AS) {
Some(self.parse_expr()?)
} else {
None
};
Ok(Statement::Assert { condition, message })
}
pub fn parse_prefix(&mut self) -> Result<Expr, ParserError> {
return_ok_if_some!(self.maybe_parse(|parser| {
match parser.parse_data_type()? {
DataType::Interval => parser.parse_literal_interval(),
DataType::Custom(..) => parser_err!("dummy"),
data_type => Ok(Expr::TypedString {
data_type,
value: parser.parse_literal_string()?,
}),
}
}));
let expr = match self.next_token() {
Token::Word(w) => match w.keyword {
Keyword::TRUE | Keyword::FALSE | Keyword::NULL => {
self.prev_token();
Ok(Expr::Value(self.parse_value()?))
}
Keyword::CASE => self.parse_case_expr(),
Keyword::CAST => self.parse_cast_expr(),
Keyword::EXISTS => self.parse_exists_expr(),
Keyword::EXTRACT => self.parse_extract_expr(),
Keyword::INTERVAL => self.parse_literal_interval(),
Keyword::LISTAGG => self.parse_listagg_expr(),
Keyword::NOT => Ok(Expr::UnaryOp {
op: UnaryOperator::Not,
expr: Box::new(self.parse_subexpr(Self::UNARY_NOT_PREC)?),
}),
_ => match self.peek_token() {
Token::LParen | Token::Period => {
let mut id_parts: Vec<Ident> = vec![w.to_ident()];
let mut ends_with_wildcard = false;
while self.consume_token(&Token::Period) {
match self.next_token() {
Token::Word(w) => id_parts.push(w.to_ident()),
Token::Mult => {
ends_with_wildcard = true;
break;
}
unexpected => {
return self
.expected("an identifier or a '*' after '.'", unexpected);
}
}
}
if ends_with_wildcard {
Ok(Expr::QualifiedWildcard(id_parts))
} else if self.consume_token(&Token::LParen) {
self.prev_token();
self.parse_function(ObjectName(id_parts))
} else {
Ok(Expr::CompoundIdentifier(id_parts))
}
}
_ => Ok(Expr::Identifier(w.to_ident())),
},
},
Token::Mult => Ok(Expr::Wildcard),
tok @ Token::Minus | tok @ Token::Plus => {
let op = if tok == Token::Plus {
UnaryOperator::Plus
} else {
UnaryOperator::Minus
};
Ok(Expr::UnaryOp {
op,
expr: Box::new(self.parse_subexpr(Self::PLUS_MINUS_PREC)?),
})
}
Token::Number(_)
| Token::SingleQuotedString(_)
| Token::NationalStringLiteral(_)
| Token::HexStringLiteral(_) => {
self.prev_token();
Ok(Expr::Value(self.parse_value()?))
}
Token::LParen => {
let expr =
if self.parse_keyword(Keyword::SELECT) || self.parse_keyword(Keyword::WITH) {
self.prev_token();
Expr::Subquery(Box::new(self.parse_query()?))
} else {
Expr::Nested(Box::new(self.parse_expr()?))
};
self.expect_token(&Token::RParen)?;
Ok(expr)
}
unexpected => self.expected("an expression", unexpected),
}?;
if self.parse_keyword(Keyword::COLLATE) {
Ok(Expr::Collate {
expr: Box::new(expr),
collation: self.parse_object_name()?,
})
} else {
Ok(expr)
}
}
pub fn parse_function(&mut self, name: ObjectName) -> Result<Expr, ParserError> {
self.expect_token(&Token::LParen)?;
let distinct = self.parse_all_or_distinct()?;
let args = self.parse_optional_args()?;
let over = if self.parse_keyword(Keyword::OVER) {
self.expect_token(&Token::LParen)?;
let partition_by = if self.parse_keywords(&[Keyword::PARTITION, Keyword::BY]) {
self.parse_comma_separated(Parser::parse_expr)?
} else {
vec![]
};
let order_by = if self.parse_keywords(&[Keyword::ORDER, Keyword::BY]) {
self.parse_comma_separated(Parser::parse_order_by_expr)?
} else {
vec![]
};
let window_frame = if !self.consume_token(&Token::RParen) {
let window_frame = self.parse_window_frame()?;
self.expect_token(&Token::RParen)?;
Some(window_frame)
} else {
None
};
Some(WindowSpec {
partition_by,
order_by,
window_frame,
})
} else {
None
};
Ok(Expr::Function(Function {
name,
args,
over,
distinct,
}))
}
pub fn parse_window_frame_units(&mut self) -> Result<WindowFrameUnits, ParserError> {
match self.next_token() {
Token::Word(w) => match w.keyword {
Keyword::ROWS => Ok(WindowFrameUnits::Rows),
Keyword::RANGE => Ok(WindowFrameUnits::Range),
Keyword::GROUPS => Ok(WindowFrameUnits::Groups),
_ => self.expected("ROWS, RANGE, GROUPS", Token::Word(w))?,
},
unexpected => self.expected("ROWS, RANGE, GROUPS", unexpected),
}
}
pub fn parse_window_frame(&mut self) -> Result<WindowFrame, ParserError> {
let units = self.parse_window_frame_units()?;
let (start_bound, end_bound) = if self.parse_keyword(Keyword::BETWEEN) {
let start_bound = self.parse_window_frame_bound()?;
self.expect_keyword(Keyword::AND)?;
let end_bound = Some(self.parse_window_frame_bound()?);
(start_bound, end_bound)
} else {
(self.parse_window_frame_bound()?, None)
};
Ok(WindowFrame {
units,
start_bound,
end_bound,
})
}
pub fn parse_window_frame_bound(&mut self) -> Result<WindowFrameBound, ParserError> {
if self.parse_keywords(&[Keyword::CURRENT, Keyword::ROW]) {
Ok(WindowFrameBound::CurrentRow)
} else {
let rows = if self.parse_keyword(Keyword::UNBOUNDED) {
None
} else {
Some(self.parse_literal_uint()?)
};
if self.parse_keyword(Keyword::PRECEDING) {
Ok(WindowFrameBound::Preceding(rows))
} else if self.parse_keyword(Keyword::FOLLOWING) {
Ok(WindowFrameBound::Following(rows))
} else {
self.expected("PRECEDING or FOLLOWING", self.peek_token())
}
}
}
pub fn parse_case_expr(&mut self) -> Result<Expr, ParserError> {
let mut operand = None;
if !self.parse_keyword(Keyword::WHEN) {
operand = Some(Box::new(self.parse_expr()?));
self.expect_keyword(Keyword::WHEN)?;
}
let mut conditions = vec![];
let mut results = vec![];
loop {
conditions.push(self.parse_expr()?);
self.expect_keyword(Keyword::THEN)?;
results.push(self.parse_expr()?);
if !self.parse_keyword(Keyword::WHEN) {
break;
}
}
let else_result = if self.parse_keyword(Keyword::ELSE) {
Some(Box::new(self.parse_expr()?))
} else {
None
};
self.expect_keyword(Keyword::END)?;
Ok(Expr::Case {
operand,
conditions,
results,
else_result,
})
}
pub fn parse_cast_expr(&mut self) -> Result<Expr, ParserError> {
self.expect_token(&Token::LParen)?;
let expr = self.parse_expr()?;
self.expect_keyword(Keyword::AS)?;
let data_type = self.parse_data_type()?;
self.expect_token(&Token::RParen)?;
Ok(Expr::Cast {
expr: Box::new(expr),
data_type,
})
}
pub fn parse_exists_expr(&mut self) -> Result<Expr, ParserError> {
self.expect_token(&Token::LParen)?;
let exists_node = Expr::Exists(Box::new(self.parse_query()?));
self.expect_token(&Token::RParen)?;
Ok(exists_node)
}
pub fn parse_extract_expr(&mut self) -> Result<Expr, ParserError> {
self.expect_token(&Token::LParen)?;
let field = self.parse_date_time_field()?;
self.expect_keyword(Keyword::FROM)?;
let expr = self.parse_expr()?;
self.expect_token(&Token::RParen)?;
Ok(Expr::Extract {
field,
expr: Box::new(expr),
})
}
pub fn parse_listagg_expr(&mut self) -> Result<Expr, ParserError> {
self.expect_token(&Token::LParen)?;
let distinct = self.parse_all_or_distinct()?;
let expr = Box::new(self.parse_expr()?);
let separator = if self.consume_token(&Token::Comma) {
Some(Box::new(self.parse_expr()?))
} else {
None
};
let on_overflow = if self.parse_keywords(&[Keyword::ON, Keyword::OVERFLOW]) {
if self.parse_keyword(Keyword::ERROR) {
Some(ListAggOnOverflow::Error)
} else {
self.expect_keyword(Keyword::TRUNCATE)?;
let filler = match self.peek_token() {
Token::Word(w)
if w.keyword == Keyword::WITH || w.keyword == Keyword::WITHOUT =>
{
None
}
Token::SingleQuotedString(_)
| Token::NationalStringLiteral(_)
| Token::HexStringLiteral(_) => Some(Box::new(self.parse_expr()?)),
unexpected => {
self.expected("either filler, WITH, or WITHOUT in LISTAGG", unexpected)?
}
};
let with_count = self.parse_keyword(Keyword::WITH);
if !with_count && !self.parse_keyword(Keyword::WITHOUT) {
self.expected("either WITH or WITHOUT in LISTAGG", self.peek_token())?;
}
self.expect_keyword(Keyword::COUNT)?;
Some(ListAggOnOverflow::Truncate { filler, with_count })
}
} else {
None
};
self.expect_token(&Token::RParen)?;
let within_group = if self.parse_keywords(&[Keyword::WITHIN, Keyword::GROUP]) {
self.expect_token(&Token::LParen)?;
self.expect_keywords(&[Keyword::ORDER, Keyword::BY])?;
let order_by_expr = self.parse_comma_separated(Parser::parse_order_by_expr)?;
self.expect_token(&Token::RParen)?;
order_by_expr
} else {
vec![]
};
Ok(Expr::ListAgg(ListAgg {
distinct,
expr,
separator,
on_overflow,
within_group,
}))
}
pub fn parse_date_time_field(&mut self) -> Result<DateTimeField, ParserError> {
match self.next_token() {
Token::Word(w) => match w.keyword {
Keyword::YEAR => Ok(DateTimeField::Year),
Keyword::MONTH => Ok(DateTimeField::Month),
Keyword::DAY => Ok(DateTimeField::Day),
Keyword::HOUR => Ok(DateTimeField::Hour),
Keyword::MINUTE => Ok(DateTimeField::Minute),
Keyword::SECOND => Ok(DateTimeField::Second),
_ => self.expected("date/time field", Token::Word(w))?,
},
unexpected => self.expected("date/time field", unexpected),
}
}
pub fn parse_literal_interval(&mut self) -> Result<Expr, ParserError> {
let value = self.parse_literal_string()?;
let leading_field = match self.peek_token() {
Token::Word(kw)
if [
Keyword::YEAR,
Keyword::MONTH,
Keyword::DAY,
Keyword::HOUR,
Keyword::MINUTE,
Keyword::SECOND,
]
.iter()
.any(|d| kw.keyword == *d) =>
{
Some(self.parse_date_time_field()?)
}
_ => None,
};
let (leading_precision, last_field, fsec_precision) =
if leading_field == Some(DateTimeField::Second) {
let last_field = None;
let (leading_precision, fsec_precision) = self.parse_optional_precision_scale()?;
(leading_precision, last_field, fsec_precision)
} else {
let leading_precision = self.parse_optional_precision()?;
if self.parse_keyword(Keyword::TO) {
let last_field = Some(self.parse_date_time_field()?);
let fsec_precision = if last_field == Some(DateTimeField::Second) {
self.parse_optional_precision()?
} else {
None
};
(leading_precision, last_field, fsec_precision)
} else {
(leading_precision, None, None)
}
};
Ok(Expr::Value(Value::Interval {
value,
leading_field,
leading_precision,
last_field,
fractional_seconds_precision: fsec_precision,
}))
}
pub fn parse_infix(&mut self, expr: Expr, precedence: u8) -> Result<Expr, ParserError> {
let tok = self.next_token();
let regular_binary_operator = match &tok {
Token::Eq => Some(BinaryOperator::Eq),
Token::Neq => Some(BinaryOperator::NotEq),
Token::Gt => Some(BinaryOperator::Gt),
Token::GtEq => Some(BinaryOperator::GtEq),
Token::Lt => Some(BinaryOperator::Lt),
Token::LtEq => Some(BinaryOperator::LtEq),
Token::Plus => Some(BinaryOperator::Plus),
Token::Minus => Some(BinaryOperator::Minus),
Token::Mult => Some(BinaryOperator::Multiply),
Token::Mod => Some(BinaryOperator::Modulus),
Token::StringConcat => Some(BinaryOperator::StringConcat),
Token::Pipe => Some(BinaryOperator::BitwiseOr),
Token::Caret => Some(BinaryOperator::BitwiseXor),
Token::Ampersand => Some(BinaryOperator::BitwiseAnd),
Token::Div => Some(BinaryOperator::Divide),
Token::Word(w) => match w.keyword {
Keyword::AND => Some(BinaryOperator::And),
Keyword::OR => Some(BinaryOperator::Or),
Keyword::LIKE => Some(BinaryOperator::Like),
Keyword::NOT => {
if self.parse_keyword(Keyword::LIKE) {
Some(BinaryOperator::NotLike)
} else {
None
}
}
_ => None,
},
_ => None,
};
if let Some(op) = regular_binary_operator {
Ok(Expr::BinaryOp {
left: Box::new(expr),
op,
right: Box::new(self.parse_subexpr(precedence)?),
})
} else if let Token::Word(w) = &tok {
match w.keyword {
Keyword::IS => {
if self.parse_keyword(Keyword::NULL) {
Ok(Expr::IsNull(Box::new(expr)))
} else if self.parse_keywords(&[Keyword::NOT, Keyword::NULL]) {
Ok(Expr::IsNotNull(Box::new(expr)))
} else {
self.expected("NULL or NOT NULL after IS", self.peek_token())
}
}
Keyword::NOT | Keyword::IN | Keyword::BETWEEN => {
self.prev_token();
let negated = self.parse_keyword(Keyword::NOT);
if self.parse_keyword(Keyword::IN) {
self.parse_in(expr, negated)
} else if self.parse_keyword(Keyword::BETWEEN) {
self.parse_between(expr, negated)
} else {
self.expected("IN or BETWEEN after NOT", self.peek_token())
}
}
_ => panic!("No infix parser for token {:?}", tok),
}
} else if Token::DoubleColon == tok {
self.parse_pg_cast(expr)
} else {
panic!("No infix parser for token {:?}", tok)
}
}
pub fn parse_in(&mut self, expr: Expr, negated: bool) -> Result<Expr, ParserError> {
self.expect_token(&Token::LParen)?;
let in_op = if self.parse_keyword(Keyword::SELECT) || self.parse_keyword(Keyword::WITH) {
self.prev_token();
Expr::InSubquery {
expr: Box::new(expr),
subquery: Box::new(self.parse_query()?),
negated,
}
} else {
Expr::InList {
expr: Box::new(expr),
list: self.parse_comma_separated(Parser::parse_expr)?,
negated,
}
};
self.expect_token(&Token::RParen)?;
Ok(in_op)
}
pub fn parse_between(&mut self, expr: Expr, negated: bool) -> Result<Expr, ParserError> {
let low = self.parse_subexpr(Self::BETWEEN_PREC)?;
self.expect_keyword(Keyword::AND)?;
let high = self.parse_subexpr(Self::BETWEEN_PREC)?;
Ok(Expr::Between {
expr: Box::new(expr),
negated,
low: Box::new(low),
high: Box::new(high),
})
}
pub fn parse_pg_cast(&mut self, expr: Expr) -> Result<Expr, ParserError> {
Ok(Expr::Cast {
expr: Box::new(expr),
data_type: self.parse_data_type()?,
})
}
const UNARY_NOT_PREC: u8 = 15;
const BETWEEN_PREC: u8 = 20;
const PLUS_MINUS_PREC: u8 = 30;
pub fn get_next_precedence(&self) -> Result<u8, ParserError> {
let token = self.peek_token();
debug!("get_next_precedence() {:?}", token);
match token {
Token::Word(w) if w.keyword == Keyword::OR => Ok(5),
Token::Word(w) if w.keyword == Keyword::AND => Ok(10),
Token::Word(w) if w.keyword == Keyword::NOT => match self.peek_nth_token(1) {
Token::Word(w) if w.keyword == Keyword::IN => Ok(Self::BETWEEN_PREC),
Token::Word(w) if w.keyword == Keyword::BETWEEN => Ok(Self::BETWEEN_PREC),
Token::Word(w) if w.keyword == Keyword::LIKE => Ok(Self::BETWEEN_PREC),
_ => Ok(0),
},
Token::Word(w) if w.keyword == Keyword::IS => Ok(17),
Token::Word(w) if w.keyword == Keyword::IN => Ok(Self::BETWEEN_PREC),
Token::Word(w) if w.keyword == Keyword::BETWEEN => Ok(Self::BETWEEN_PREC),
Token::Word(w) if w.keyword == Keyword::LIKE => Ok(Self::BETWEEN_PREC),
Token::Eq | Token::Lt | Token::LtEq | Token::Neq | Token::Gt | Token::GtEq => Ok(20),
Token::Pipe => Ok(21),
Token::Caret => Ok(22),
Token::Ampersand => Ok(23),
Token::Plus | Token::Minus => Ok(Self::PLUS_MINUS_PREC),
Token::Mult | Token::Div | Token::Mod | Token::StringConcat => Ok(40),
Token::DoubleColon => Ok(50),
_ => Ok(0),
}
}
pub fn peek_token(&self) -> Token {
self.peek_nth_token(0)
}
pub fn peek_nth_token(&self, mut n: usize) -> Token {
let mut index = self.index;
loop {
index += 1;
match self.tokens.get(index - 1) {
Some(Token::Whitespace(_)) => continue,
non_whitespace => {
if n == 0 {
return non_whitespace.cloned().unwrap_or(Token::EOF);
}
n -= 1;
}
}
}
}
pub fn next_token(&mut self) -> Token {
loop {
self.index += 1;
match self.tokens.get(self.index - 1) {
Some(Token::Whitespace(_)) => continue,
token => return token.cloned().unwrap_or(Token::EOF),
}
}
}
pub fn next_token_no_skip(&mut self) -> Option<&Token> {
self.index += 1;
self.tokens.get(self.index - 1)
}
pub fn prev_token(&mut self) {
loop {
assert!(self.index > 0);
self.index -= 1;
if let Some(Token::Whitespace(_)) = self.tokens.get(self.index) {
continue;
}
return;
}
}
fn expected<T>(&self, expected: &str, found: Token) -> Result<T, ParserError> {
parser_err!(format!("Expected {}, found: {}", expected, found))
}
#[must_use]
pub fn parse_keyword(&mut self, expected: Keyword) -> bool {
match self.peek_token() {
Token::Word(w) if expected == w.keyword => {
self.next_token();
true
}
_ => false,
}
}
#[must_use]
pub fn parse_keywords(&mut self, keywords: &[Keyword]) -> bool {
let index = self.index;
for &keyword in keywords {
if !self.parse_keyword(keyword) {
self.index = index;
return false;
}
}
true
}
#[must_use]
pub fn parse_one_of_keywords(&mut self, keywords: &[Keyword]) -> Option<Keyword> {
match self.peek_token() {
Token::Word(w) => {
keywords
.iter()
.find(|keyword| **keyword == w.keyword)
.map(|keyword| {
self.next_token();
*keyword
})
}
_ => None,
}
}
pub fn expect_one_of_keywords(&mut self, keywords: &[Keyword]) -> Result<Keyword, ParserError> {
if let Some(keyword) = self.parse_one_of_keywords(keywords) {
Ok(keyword)
} else {
let keywords: Vec<String> = keywords.iter().map(|x| format!("{:?}", x)).collect();
self.expected(
&format!("one of {}", keywords.join(" or ")),
self.peek_token(),
)
}
}
pub fn expect_keyword(&mut self, expected: Keyword) -> Result<(), ParserError> {
if self.parse_keyword(expected) {
Ok(())
} else {
self.expected(format!("{:?}", &expected).as_str(), self.peek_token())
}
}
pub fn expect_keywords(&mut self, expected: &[Keyword]) -> Result<(), ParserError> {
for &kw in expected {
self.expect_keyword(kw)?;
}
Ok(())
}
#[must_use]
pub fn consume_token(&mut self, expected: &Token) -> bool {
if self.peek_token() == *expected {
self.next_token();
true
} else {
false
}
}
pub fn expect_token(&mut self, expected: &Token) -> Result<(), ParserError> {
if self.consume_token(expected) {
Ok(())
} else {
self.expected(&expected.to_string(), self.peek_token())
}
}
pub fn parse_comma_separated<T, F>(&mut self, mut f: F) -> Result<Vec<T>, ParserError>
where
F: FnMut(&mut Parser) -> Result<T, ParserError>,
{
let mut values = vec![];
loop {
values.push(f(self)?);
if !self.consume_token(&Token::Comma) {
break;
}
}
Ok(values)
}
#[must_use]
fn maybe_parse<T, F>(&mut self, mut f: F) -> Option<T>
where
F: FnMut(&mut Parser) -> Result<T, ParserError>,
{
let index = self.index;
if let Ok(t) = f(self) {
Some(t)
} else {
self.index = index;
None
}
}
pub fn parse_all_or_distinct(&mut self) -> Result<bool, ParserError> {
let all = self.parse_keyword(Keyword::ALL);
let distinct = self.parse_keyword(Keyword::DISTINCT);
if all && distinct {
return parser_err!("Cannot specify both ALL and DISTINCT".to_string());
} else {
Ok(distinct)
}
}
pub fn parse_create(&mut self) -> Result<Statement, ParserError> {
if self.parse_keyword(Keyword::TABLE) {
self.parse_create_table()
} else if self.parse_keyword(Keyword::INDEX) {
self.parse_create_index(false)
} else if self.parse_keywords(&[Keyword::UNIQUE, Keyword::INDEX]) {
self.parse_create_index(true)
} else if self.parse_keyword(Keyword::MATERIALIZED) || self.parse_keyword(Keyword::VIEW) {
self.prev_token();
self.parse_create_view()
} else if self.parse_keyword(Keyword::EXTERNAL) {
self.parse_create_external_table()
} else if self.parse_keyword(Keyword::VIRTUAL) {
self.parse_create_virtual_table()
} else if self.parse_keyword(Keyword::SCHEMA) {
self.parse_create_schema()
} else {
self.expected("an object type after CREATE", self.peek_token())
}
}
pub fn parse_create_virtual_table(&mut self) -> Result<Statement, ParserError> {
self.expect_keyword(Keyword::TABLE)?;
let if_not_exists = self.parse_keywords(&[Keyword::IF, Keyword::NOT, Keyword::EXISTS]);
let table_name = self.parse_object_name()?;
self.expect_keyword(Keyword::USING)?;
let module_name = self.parse_identifier()?;
let module_args = self.parse_parenthesized_column_list(Optional)?;
Ok(CreateVirtualTable {
name: table_name,
if_not_exists,
module_name,
module_args,
})
}
pub fn parse_create_schema(&mut self) -> Result<Statement, ParserError> {
let schema_name = self.parse_object_name()?;
Ok(Statement::CreateSchema { schema_name })
}
pub fn parse_create_external_table(&mut self) -> Result<Statement, ParserError> {
self.expect_keyword(Keyword::TABLE)?;
let table_name = self.parse_object_name()?;
let (columns, constraints) = self.parse_columns()?;
self.expect_keywords(&[Keyword::STORED, Keyword::AS])?;
let file_format = self.parse_file_format()?;
self.expect_keyword(Keyword::LOCATION)?;
let location = self.parse_literal_string()?;
Ok(Statement::CreateTable {
name: table_name,
columns,
constraints,
with_options: vec![],
if_not_exists: false,
external: true,
file_format: Some(file_format),
location: Some(location),
query: None,
without_rowid: false,
})
}
pub fn parse_file_format(&mut self) -> Result<FileFormat, ParserError> {
match self.next_token() {
Token::Word(w) => match w.keyword {
Keyword::AVRO => Ok(FileFormat::AVRO),
Keyword::JSONFILE => Ok(FileFormat::JSONFILE),
Keyword::ORC => Ok(FileFormat::ORC),
Keyword::PARQUET => Ok(FileFormat::PARQUET),
Keyword::RCFILE => Ok(FileFormat::RCFILE),
Keyword::SEQUENCEFILE => Ok(FileFormat::SEQUENCEFILE),
Keyword::TEXTFILE => Ok(FileFormat::TEXTFILE),
_ => self.expected("fileformat", Token::Word(w)),
},
unexpected => self.expected("fileformat", unexpected),
}
}
pub fn parse_create_view(&mut self) -> Result<Statement, ParserError> {
let materialized = self.parse_keyword(Keyword::MATERIALIZED);
self.expect_keyword(Keyword::VIEW)?;
let name = self.parse_object_name()?;
let columns = self.parse_parenthesized_column_list(Optional)?;
let with_options = self.parse_with_options()?;
self.expect_keyword(Keyword::AS)?;
let query = Box::new(self.parse_query()?);
Ok(Statement::CreateView {
name,
columns,
query,
materialized,
with_options,
})
}
pub fn parse_drop(&mut self) -> Result<Statement, ParserError> {
let object_type = if self.parse_keyword(Keyword::TABLE) {
ObjectType::Table
} else if self.parse_keyword(Keyword::VIEW) {
ObjectType::View
} else if self.parse_keyword(Keyword::INDEX) {
ObjectType::Index
} else if self.parse_keyword(Keyword::SCHEMA) {
ObjectType::Schema
} else {
return self.expected("TABLE, VIEW, INDEX or SCHEMA after DROP", self.peek_token());
};
let if_exists = self.parse_keywords(&[Keyword::IF, Keyword::EXISTS]);
let names = self.parse_comma_separated(Parser::parse_object_name)?;
let cascade = self.parse_keyword(Keyword::CASCADE);
let restrict = self.parse_keyword(Keyword::RESTRICT);
if cascade && restrict {
return parser_err!("Cannot specify both CASCADE and RESTRICT in DROP");
}
Ok(Statement::Drop {
object_type,
if_exists,
names,
cascade,
})
}
pub fn parse_create_index(&mut self, unique: bool) -> Result<Statement, ParserError> {
let if_not_exists = self.parse_keywords(&[Keyword::IF, Keyword::NOT, Keyword::EXISTS]);
let index_name = self.parse_object_name()?;
self.expect_keyword(Keyword::ON)?;
let table_name = self.parse_object_name()?;
let columns = self.parse_parenthesized_column_list(Mandatory)?;
Ok(Statement::CreateIndex {
name: index_name,
table_name,
columns,
unique,
if_not_exists,
})
}
pub fn parse_create_table(&mut self) -> Result<Statement, ParserError> {
let if_not_exists = self.parse_keywords(&[Keyword::IF, Keyword::NOT, Keyword::EXISTS]);
let table_name = self.parse_object_name()?;
let (columns, constraints) = self.parse_columns()?;
let without_rowid = self.parse_keywords(&[Keyword::WITHOUT, Keyword::ROWID]);
let with_options = self.parse_with_options()?;
let query = if self.parse_keyword(Keyword::AS) {
Some(Box::new(self.parse_query()?))
} else {
None
};
Ok(Statement::CreateTable {
name: table_name,
columns,
constraints,
with_options,
if_not_exists,
external: false,
file_format: None,
location: None,
query,
without_rowid,
})
}
fn parse_column_def(&mut self) -> Result<ColumnDef, ParserError> {
let name = self.parse_identifier()?;
let data_type = self.parse_data_type()?;
let collation = if self.parse_keyword(Keyword::COLLATE) {
Some(self.parse_object_name()?)
} else {
None
};
let mut options = vec![];
loop {
match self.peek_token() {
Token::EOF | Token::Comma | Token::RParen => break,
_ => options.push(self.parse_column_option_def()?),
}
}
Ok(ColumnDef {
name,
data_type,
collation,
options,
})
}
fn parse_columns(&mut self) -> Result<(Vec<ColumnDef>, Vec<TableConstraint>), ParserError> {
let mut columns = vec![];
let mut constraints = vec![];
if !self.consume_token(&Token::LParen) || self.consume_token(&Token::RParen) {
return Ok((columns, constraints));
}
loop {
if let Some(constraint) = self.parse_optional_table_constraint()? {
constraints.push(constraint);
} else if let Token::Word(_) = self.peek_token() {
let column_def = self.parse_column_def()?;
columns.push(column_def);
} else {
return self.expected("column name or constraint definition", self.peek_token());
}
let comma = self.consume_token(&Token::Comma);
if self.consume_token(&Token::RParen) {
break;
} else if !comma {
return self.expected("',' or ')' after column definition", self.peek_token());
}
}
Ok((columns, constraints))
}
pub fn parse_column_option_def(&mut self) -> Result<ColumnOptionDef, ParserError> {
let name = if self.parse_keyword(Keyword::CONSTRAINT) {
Some(self.parse_identifier()?)
} else {
None
};
let option = if self.parse_keywords(&[Keyword::NOT, Keyword::NULL]) {
ColumnOption::NotNull
} else if self.parse_keyword(Keyword::NULL) {
ColumnOption::Null
} else if self.parse_keyword(Keyword::DEFAULT) {
ColumnOption::Default(self.parse_expr()?)
} else if self.parse_keywords(&[Keyword::PRIMARY, Keyword::KEY]) {
ColumnOption::Unique { is_primary: true }
} else if self.parse_keyword(Keyword::UNIQUE) {
ColumnOption::Unique { is_primary: false }
} else if self.parse_keyword(Keyword::REFERENCES) {
let foreign_table = self.parse_object_name()?;
let referred_columns = self.parse_parenthesized_column_list(Optional)?;
let mut on_delete = None;
let mut on_update = None;
loop {
if on_delete.is_none() && self.parse_keywords(&[Keyword::ON, Keyword::DELETE]) {
on_delete = Some(self.parse_referential_action()?);
} else if on_update.is_none()
&& self.parse_keywords(&[Keyword::ON, Keyword::UPDATE])
{
on_update = Some(self.parse_referential_action()?);
} else {
break;
}
}
ColumnOption::ForeignKey {
foreign_table,
referred_columns,
on_delete,
on_update,
}
} else if self.parse_keyword(Keyword::CHECK) {
self.expect_token(&Token::LParen)?;
let expr = self.parse_expr()?;
self.expect_token(&Token::RParen)?;
ColumnOption::Check(expr)
} else {
return self.expected("column option", self.peek_token());
};
Ok(ColumnOptionDef { name, option })
}
pub fn parse_referential_action(&mut self) -> Result<ReferentialAction, ParserError> {
if self.parse_keyword(Keyword::RESTRICT) {
Ok(ReferentialAction::Restrict)
} else if self.parse_keyword(Keyword::CASCADE) {
Ok(ReferentialAction::Cascade)
} else if self.parse_keywords(&[Keyword::SET, Keyword::NULL]) {
Ok(ReferentialAction::SetNull)
} else if self.parse_keywords(&[Keyword::NO, Keyword::ACTION]) {
Ok(ReferentialAction::NoAction)
} else if self.parse_keywords(&[Keyword::SET, Keyword::DEFAULT]) {
Ok(ReferentialAction::SetDefault)
} else {
self.expected(
"one of RESTRICT, CASCADE, SET NULL, NO ACTION or SET DEFAULT",
self.peek_token(),
)
}
}
pub fn parse_optional_table_constraint(
&mut self,
) -> Result<Option<TableConstraint>, ParserError> {
let name = if self.parse_keyword(Keyword::CONSTRAINT) {
Some(self.parse_identifier()?)
} else {
None
};
match self.next_token() {
Token::Word(w) if w.keyword == Keyword::PRIMARY || w.keyword == Keyword::UNIQUE => {
let is_primary = w.keyword == Keyword::PRIMARY;
if is_primary {
self.expect_keyword(Keyword::KEY)?;
}
let columns = self.parse_parenthesized_column_list(Mandatory)?;
Ok(Some(TableConstraint::Unique {
name,
columns,
is_primary,
}))
}
Token::Word(w) if w.keyword == Keyword::FOREIGN => {
self.expect_keyword(Keyword::KEY)?;
let columns = self.parse_parenthesized_column_list(Mandatory)?;
self.expect_keyword(Keyword::REFERENCES)?;
let foreign_table = self.parse_object_name()?;
let referred_columns = self.parse_parenthesized_column_list(Mandatory)?;
Ok(Some(TableConstraint::ForeignKey {
name,
columns,
foreign_table,
referred_columns,
}))
}
Token::Word(w) if w.keyword == Keyword::CHECK => {
self.expect_token(&Token::LParen)?;
let expr = Box::new(self.parse_expr()?);
self.expect_token(&Token::RParen)?;
Ok(Some(TableConstraint::Check { name, expr }))
}
unexpected => {
if name.is_some() {
self.expected("PRIMARY, UNIQUE, FOREIGN, or CHECK", unexpected)
} else {
self.prev_token();
Ok(None)
}
}
}
}
pub fn parse_with_options(&mut self) -> Result<Vec<SqlOption>, ParserError> {
if self.parse_keyword(Keyword::WITH) {
self.expect_token(&Token::LParen)?;
let options = self.parse_comma_separated(Parser::parse_sql_option)?;
self.expect_token(&Token::RParen)?;
Ok(options)
} else {
Ok(vec![])
}
}
pub fn parse_sql_option(&mut self) -> Result<SqlOption, ParserError> {
let name = self.parse_identifier()?;
self.expect_token(&Token::Eq)?;
let value = self.parse_value()?;
Ok(SqlOption { name, value })
}
pub fn parse_alter(&mut self) -> Result<Statement, ParserError> {
self.expect_keyword(Keyword::TABLE)?;
let _ = self.parse_keyword(Keyword::ONLY);
let table_name = self.parse_object_name()?;
let operation = if self.parse_keyword(Keyword::ADD) {
if let Some(constraint) = self.parse_optional_table_constraint()? {
AlterTableOperation::AddConstraint(constraint)
} else {
let _ = self.parse_keyword(Keyword::COLUMN);
let column_def = self.parse_column_def()?;
AlterTableOperation::AddColumn { column_def }
}
} else if self.parse_keyword(Keyword::RENAME) {
if self.parse_keyword(Keyword::TO) {
let table_name = self.parse_identifier()?;
AlterTableOperation::RenameTable { table_name }
} else {
let _ = self.parse_keyword(Keyword::COLUMN);
let old_column_name = self.parse_identifier()?;
self.expect_keyword(Keyword::TO)?;
let new_column_name = self.parse_identifier()?;
AlterTableOperation::RenameColumn {
old_column_name,
new_column_name,
}
}
} else if self.parse_keyword(Keyword::DROP) {
let _ = self.parse_keyword(Keyword::COLUMN);
let if_exists = self.parse_keywords(&[Keyword::IF, Keyword::EXISTS]);
let column_name = self.parse_identifier()?;
let cascade = self.parse_keyword(Keyword::CASCADE);
AlterTableOperation::DropColumn {
column_name,
if_exists,
cascade,
}
} else {
return self.expected("ADD, RENAME, or DROP after ALTER TABLE", self.peek_token());
};
Ok(Statement::AlterTable {
name: table_name,
operation,
})
}
pub fn parse_copy(&mut self) -> Result<Statement, ParserError> {
let table_name = self.parse_object_name()?;
let columns = self.parse_parenthesized_column_list(Optional)?;
self.expect_keywords(&[Keyword::FROM, Keyword::STDIN])?;
self.expect_token(&Token::SemiColon)?;
let values = self.parse_tsv()?;
Ok(Statement::Copy {
table_name,
columns,
values,
})
}
fn parse_tsv(&mut self) -> Result<Vec<Option<String>>, ParserError> {
let values = self.parse_tab_value()?;
Ok(values)
}
fn parse_tab_value(&mut self) -> Result<Vec<Option<String>>, ParserError> {
let mut values = vec![];
let mut content = String::from("");
while let Some(t) = self.next_token_no_skip() {
match t {
Token::Whitespace(Whitespace::Tab) => {
values.push(Some(content.to_string()));
content.clear();
}
Token::Whitespace(Whitespace::Newline) => {
values.push(Some(content.to_string()));
content.clear();
}
Token::Backslash => {
if self.consume_token(&Token::Period) {
return Ok(values);
}
if let Token::Word(w) = self.next_token() {
if w.value == "N" {
values.push(None);
}
}
}
_ => {
content.push_str(&t.to_string());
}
}
}
Ok(values)
}
fn parse_value(&mut self) -> Result<Value, ParserError> {
match self.next_token() {
Token::Word(w) => match w.keyword {
Keyword::TRUE => Ok(Value::Boolean(true)),
Keyword::FALSE => Ok(Value::Boolean(false)),
Keyword::NULL => Ok(Value::Null),
_ => self.expected("a concrete value", Token::Word(w)),
},
Token::Number(ref n) => match n.parse() {
Ok(n) => Ok(Value::Number(n)),
Err(e) => parser_err!(format!("Could not parse '{}' as number: {}", n, e)),
},
Token::SingleQuotedString(ref s) => Ok(Value::SingleQuotedString(s.to_string())),
Token::NationalStringLiteral(ref s) => Ok(Value::NationalStringLiteral(s.to_string())),
Token::HexStringLiteral(ref s) => Ok(Value::HexStringLiteral(s.to_string())),
unexpected => self.expected("a value", unexpected),
}
}
pub fn parse_number_value(&mut self) -> Result<Value, ParserError> {
match self.parse_value()? {
v @ Value::Number(_) => Ok(v),
_ => {
self.prev_token();
self.expected("literal number", self.peek_token())
}
}
}
pub fn parse_literal_uint(&mut self) -> Result<u64, ParserError> {
match self.next_token() {
Token::Number(s) => s.parse::<u64>().map_err(|e| {
ParserError::ParserError(format!("Could not parse '{}' as u64: {}", s, e))
}),
unexpected => self.expected("literal int", unexpected),
}
}
pub fn parse_literal_string(&mut self) -> Result<String, ParserError> {
match self.next_token() {
Token::SingleQuotedString(s) => Ok(s),
unexpected => self.expected("literal string", unexpected),
}
}
pub fn parse_data_type(&mut self) -> Result<DataType, ParserError> {
match self.next_token() {
Token::Word(w) => match w.keyword {
Keyword::BOOLEAN => Ok(DataType::Boolean),
Keyword::FLOAT => Ok(DataType::Float(self.parse_optional_precision()?)),
Keyword::REAL => Ok(DataType::Real),
Keyword::DOUBLE => {
let _ = self.parse_keyword(Keyword::PRECISION);
Ok(DataType::Double)
}
Keyword::SMALLINT => Ok(DataType::SmallInt),
Keyword::INT | Keyword::INTEGER => Ok(DataType::Int),
Keyword::BIGINT => Ok(DataType::BigInt),
Keyword::VARCHAR => Ok(DataType::Varchar(self.parse_optional_precision()?)),
Keyword::CHAR | Keyword::CHARACTER => {
if self.parse_keyword(Keyword::VARYING) {
Ok(DataType::Varchar(self.parse_optional_precision()?))
} else {
Ok(DataType::Char(self.parse_optional_precision()?))
}
}
Keyword::UUID => Ok(DataType::Uuid),
Keyword::DATE => Ok(DataType::Date),
Keyword::TIMESTAMP => {
if self.parse_keyword(Keyword::WITH) || self.parse_keyword(Keyword::WITHOUT) {
self.expect_keywords(&[Keyword::TIME, Keyword::ZONE])?;
}
Ok(DataType::Timestamp)
}
Keyword::TIME => {
if self.parse_keyword(Keyword::WITH) || self.parse_keyword(Keyword::WITHOUT) {
self.expect_keywords(&[Keyword::TIME, Keyword::ZONE])?;
}
Ok(DataType::Time)
}
Keyword::INTERVAL => Ok(DataType::Interval),
Keyword::REGCLASS => Ok(DataType::Regclass),
Keyword::TEXT => {
if self.consume_token(&Token::LBracket) {
self.expect_token(&Token::RBracket)?;
Ok(DataType::Array(Box::new(DataType::Text)))
} else {
Ok(DataType::Text)
}
}
Keyword::BYTEA => Ok(DataType::Bytea),
Keyword::NUMERIC | Keyword::DECIMAL | Keyword::DEC => {
let (precision, scale) = self.parse_optional_precision_scale()?;
Ok(DataType::Decimal(precision, scale))
}
_ => {
self.prev_token();
let type_name = self.parse_object_name()?;
Ok(DataType::Custom(type_name))
}
},
unexpected => self.expected("a data type name", unexpected),
}
}
pub fn parse_optional_alias(
&mut self,
reserved_kwds: &[Keyword],
) -> Result<Option<Ident>, ParserError> {
let after_as = self.parse_keyword(Keyword::AS);
match self.next_token() {
Token::Word(w) if after_as || !reserved_kwds.contains(&w.keyword) => {
Ok(Some(w.to_ident()))
}
Token::SingleQuotedString(s) => Ok(Some(Ident::with_quote('\'', s))),
not_an_ident => {
if after_as {
return self.expected("an identifier after AS", not_an_ident);
}
self.prev_token();
Ok(None)
}
}
}
pub fn parse_optional_table_alias(
&mut self,
reserved_kwds: &[Keyword],
) -> Result<Option<TableAlias>, ParserError> {
match self.parse_optional_alias(reserved_kwds)? {
Some(name) => {
let columns = self.parse_parenthesized_column_list(Optional)?;
Ok(Some(TableAlias { name, columns }))
}
None => Ok(None),
}
}
pub fn parse_object_name(&mut self) -> Result<ObjectName, ParserError> {
let mut idents = vec![];
loop {
idents.push(self.parse_identifier()?);
if !self.consume_token(&Token::Period) {
break;
}
}
Ok(ObjectName(idents))
}
pub fn parse_identifier(&mut self) -> Result<Ident, ParserError> {
match self.next_token() {
Token::Word(w) => Ok(w.to_ident()),
unexpected => self.expected("identifier", unexpected),
}
}
pub fn parse_parenthesized_column_list(
&mut self,
optional: IsOptional,
) -> Result<Vec<Ident>, ParserError> {
if self.consume_token(&Token::LParen) {
let cols = self.parse_comma_separated(Parser::parse_identifier)?;
self.expect_token(&Token::RParen)?;
Ok(cols)
} else if optional == Optional {
Ok(vec![])
} else {
self.expected("a list of columns in parentheses", self.peek_token())
}
}
pub fn parse_optional_precision(&mut self) -> Result<Option<u64>, ParserError> {
if self.consume_token(&Token::LParen) {
let n = self.parse_literal_uint()?;
self.expect_token(&Token::RParen)?;
Ok(Some(n))
} else {
Ok(None)
}
}
pub fn parse_optional_precision_scale(
&mut self,
) -> Result<(Option<u64>, Option<u64>), ParserError> {
if self.consume_token(&Token::LParen) {
let n = self.parse_literal_uint()?;
let scale = if self.consume_token(&Token::Comma) {
Some(self.parse_literal_uint()?)
} else {
None
};
self.expect_token(&Token::RParen)?;
Ok((Some(n), scale))
} else {
Ok((None, None))
}
}
pub fn parse_delete(&mut self) -> Result<Statement, ParserError> {
self.expect_keyword(Keyword::FROM)?;
let table_name = self.parse_object_name()?;
let selection = if self.parse_keyword(Keyword::WHERE) {
Some(self.parse_expr()?)
} else {
None
};
Ok(Statement::Delete {
table_name,
selection,
})
}
pub fn parse_query(&mut self) -> Result<Query, ParserError> {
let ctes = if self.parse_keyword(Keyword::WITH) {
self.parse_comma_separated(Parser::parse_cte)?
} else {
vec![]
};
let body = self.parse_query_body(0)?;
let order_by = if self.parse_keywords(&[Keyword::ORDER, Keyword::BY]) {
self.parse_comma_separated(Parser::parse_order_by_expr)?
} else {
vec![]
};
let limit = if self.parse_keyword(Keyword::LIMIT) {
self.parse_limit()?
} else {
None
};
let offset = if self.parse_keyword(Keyword::OFFSET) {
Some(self.parse_offset()?)
} else {
None
};
let fetch = if self.parse_keyword(Keyword::FETCH) {
Some(self.parse_fetch()?)
} else {
None
};
Ok(Query {
ctes,
body,
limit,
order_by,
offset,
fetch,
})
}
fn parse_cte(&mut self) -> Result<Cte, ParserError> {
let alias = TableAlias {
name: self.parse_identifier()?,
columns: self.parse_parenthesized_column_list(Optional)?,
};
self.expect_keyword(Keyword::AS)?;
self.expect_token(&Token::LParen)?;
let query = self.parse_query()?;
self.expect_token(&Token::RParen)?;
Ok(Cte { alias, query })
}
fn parse_query_body(&mut self, precedence: u8) -> Result<SetExpr, ParserError> {
let mut expr = if self.parse_keyword(Keyword::SELECT) {
SetExpr::Select(Box::new(self.parse_select()?))
} else if self.consume_token(&Token::LParen) {
let subquery = self.parse_query()?;
self.expect_token(&Token::RParen)?;
SetExpr::Query(Box::new(subquery))
} else if self.parse_keyword(Keyword::VALUES) {
SetExpr::Values(self.parse_values()?)
} else {
return self.expected(
"SELECT, VALUES, or a subquery in the query body",
self.peek_token(),
);
};
loop {
let op = self.parse_set_operator(&self.peek_token());
let next_precedence = match op {
Some(SetOperator::Union) | Some(SetOperator::Except) => 10,
Some(SetOperator::Intersect) => 20,
None => break,
};
if precedence >= next_precedence {
break;
}
self.next_token();
expr = SetExpr::SetOperation {
left: Box::new(expr),
op: op.unwrap(),
all: self.parse_keyword(Keyword::ALL),
right: Box::new(self.parse_query_body(next_precedence)?),
};
}
Ok(expr)
}
fn parse_set_operator(&mut self, token: &Token) -> Option<SetOperator> {
match token {
Token::Word(w) if w.keyword == Keyword::UNION => Some(SetOperator::Union),
Token::Word(w) if w.keyword == Keyword::EXCEPT => Some(SetOperator::Except),
Token::Word(w) if w.keyword == Keyword::INTERSECT => Some(SetOperator::Intersect),
_ => None,
}
}
pub fn parse_select(&mut self) -> Result<Select, ParserError> {
let distinct = self.parse_all_or_distinct()?;
let top = if self.parse_keyword(Keyword::TOP) {
Some(self.parse_top()?)
} else {
None
};
let projection = self.parse_comma_separated(Parser::parse_select_item)?;
let from = if self.parse_keyword(Keyword::FROM) {
self.parse_comma_separated(Parser::parse_table_and_joins)?
} else {
vec![]
};
let selection = if self.parse_keyword(Keyword::WHERE) {
Some(self.parse_expr()?)
} else {
None
};
let group_by = if self.parse_keywords(&[Keyword::GROUP, Keyword::BY]) {
self.parse_comma_separated(Parser::parse_expr)?
} else {
vec![]
};
let having = if self.parse_keyword(Keyword::HAVING) {
Some(self.parse_expr()?)
} else {
None
};
Ok(Select {
distinct,
top,
projection,
from,
selection,
group_by,
having,
})
}
pub fn parse_set(&mut self) -> Result<Statement, ParserError> {
let modifier = self.parse_one_of_keywords(&[Keyword::SESSION, Keyword::LOCAL]);
let variable = self.parse_identifier()?;
if self.consume_token(&Token::Eq) || self.parse_keyword(Keyword::TO) {
let token = self.peek_token();
let value = match (self.parse_value(), token) {
(Ok(value), _) => SetVariableValue::Literal(value),
(Err(_), Token::Word(ident)) => SetVariableValue::Ident(ident.to_ident()),
(Err(_), unexpected) => self.expected("variable value", unexpected)?,
};
Ok(Statement::SetVariable {
local: modifier == Some(Keyword::LOCAL),
variable,
value,
})
} else if variable.value == "TRANSACTION" && modifier.is_none() {
Ok(Statement::SetTransaction {
modes: self.parse_transaction_modes()?,
})
} else {
self.expected("equals sign or TO", self.peek_token())
}
}
pub fn parse_show(&mut self) -> Result<Statement, ParserError> {
if self
.parse_one_of_keywords(&[
Keyword::EXTENDED,
Keyword::FULL,
Keyword::COLUMNS,
Keyword::FIELDS,
])
.is_some()
{
self.prev_token();
self.parse_show_columns()
} else {
Ok(Statement::ShowVariable {
variable: self.parse_identifier()?,
})
}
}
fn parse_show_columns(&mut self) -> Result<Statement, ParserError> {
let extended = self.parse_keyword(Keyword::EXTENDED);
let full = self.parse_keyword(Keyword::FULL);
self.expect_one_of_keywords(&[Keyword::COLUMNS, Keyword::FIELDS])?;
self.expect_one_of_keywords(&[Keyword::FROM, Keyword::IN])?;
let table_name = self.parse_object_name()?;
let filter = self.parse_show_statement_filter()?;
Ok(Statement::ShowColumns {
extended,
full,
table_name,
filter,
})
}
fn parse_show_statement_filter(&mut self) -> Result<Option<ShowStatementFilter>, ParserError> {
if self.parse_keyword(Keyword::LIKE) {
Ok(Some(ShowStatementFilter::Like(
self.parse_literal_string()?,
)))
} else if self.parse_keyword(Keyword::WHERE) {
Ok(Some(ShowStatementFilter::Where(self.parse_expr()?)))
} else {
Ok(None)
}
}
pub fn parse_table_and_joins(&mut self) -> Result<TableWithJoins, ParserError> {
let relation = self.parse_table_factor()?;
let mut joins = vec![];
loop {
let join = if self.parse_keyword(Keyword::CROSS) {
let join_operator = if self.parse_keyword(Keyword::JOIN) {
JoinOperator::CrossJoin
} else if self.parse_keyword(Keyword::APPLY) {
JoinOperator::CrossApply
} else {
return self.expected("JOIN or APPLY after CROSS", self.peek_token());
};
Join {
relation: self.parse_table_factor()?,
join_operator,
}
} else if self.parse_keyword(Keyword::OUTER) {
self.expect_keyword(Keyword::APPLY)?;
Join {
relation: self.parse_table_factor()?,
join_operator: JoinOperator::OuterApply,
}
} else {
let natural = self.parse_keyword(Keyword::NATURAL);
let peek_keyword = if let Token::Word(w) = self.peek_token() {
w.keyword
} else {
Keyword::NoKeyword
};
let join_operator_type = match peek_keyword {
Keyword::INNER | Keyword::JOIN => {
let _ = self.parse_keyword(Keyword::INNER);
self.expect_keyword(Keyword::JOIN)?;
JoinOperator::Inner
}
kw @ Keyword::LEFT | kw @ Keyword::RIGHT | kw @ Keyword::FULL => {
let _ = self.next_token();
let _ = self.parse_keyword(Keyword::OUTER);
self.expect_keyword(Keyword::JOIN)?;
match kw {
Keyword::LEFT => JoinOperator::LeftOuter,
Keyword::RIGHT => JoinOperator::RightOuter,
Keyword::FULL => JoinOperator::FullOuter,
_ => unreachable!(),
}
}
Keyword::OUTER => {
return self.expected("LEFT, RIGHT, or FULL", self.peek_token())
}
_ if natural => {
return self.expected("a join type after NATURAL", self.peek_token());
}
_ => break,
};
let relation = self.parse_table_factor()?;
let join_constraint = self.parse_join_constraint(natural)?;
Join {
relation,
join_operator: join_operator_type(join_constraint),
}
};
joins.push(join);
}
Ok(TableWithJoins { relation, joins })
}
pub fn parse_table_factor(&mut self) -> Result<TableFactor, ParserError> {
if self.parse_keyword(Keyword::LATERAL) {
if !self.consume_token(&Token::LParen) {
self.expected("subquery after LATERAL", self.peek_token())?;
}
return self.parse_derived_table_factor(Lateral);
}
if self.consume_token(&Token::LParen) {
return_ok_if_some!(
self.maybe_parse(|parser| parser.parse_derived_table_factor(NotLateral))
);
let table_and_joins = self.parse_table_and_joins()?;
self.expect_token(&Token::RParen)?;
Ok(TableFactor::NestedJoin(Box::new(table_and_joins)))
} else {
let name = self.parse_object_name()?;
let args = if self.consume_token(&Token::LParen) {
self.parse_optional_args()?
} else {
vec![]
};
let alias = self.parse_optional_table_alias(keywords::RESERVED_FOR_TABLE_ALIAS)?;
let mut with_hints = vec![];
if self.parse_keyword(Keyword::WITH) {
if self.consume_token(&Token::LParen) {
with_hints = self.parse_comma_separated(Parser::parse_expr)?;
self.expect_token(&Token::RParen)?;
} else {
self.prev_token();
}
};
Ok(TableFactor::Table {
name,
alias,
args,
with_hints,
})
}
}
pub fn parse_derived_table_factor(
&mut self,
lateral: IsLateral,
) -> Result<TableFactor, ParserError> {
let subquery = Box::new(self.parse_query()?);
self.expect_token(&Token::RParen)?;
let alias = self.parse_optional_table_alias(keywords::RESERVED_FOR_TABLE_ALIAS)?;
Ok(TableFactor::Derived {
lateral: match lateral {
Lateral => true,
NotLateral => false,
},
subquery,
alias,
})
}
fn parse_join_constraint(&mut self, natural: bool) -> Result<JoinConstraint, ParserError> {
if natural {
Ok(JoinConstraint::Natural)
} else if self.parse_keyword(Keyword::ON) {
let constraint = self.parse_expr()?;
Ok(JoinConstraint::On(constraint))
} else if self.parse_keyword(Keyword::USING) {
let columns = self.parse_parenthesized_column_list(Mandatory)?;
Ok(JoinConstraint::Using(columns))
} else {
self.expected("ON, or USING after JOIN", self.peek_token())
}
}
pub fn parse_insert(&mut self) -> Result<Statement, ParserError> {
self.expect_keyword(Keyword::INTO)?;
let table_name = self.parse_object_name()?;
let columns = self.parse_parenthesized_column_list(Optional)?;
let source = Box::new(self.parse_query()?);
Ok(Statement::Insert {
table_name,
columns,
source,
})
}
pub fn parse_update(&mut self) -> Result<Statement, ParserError> {
let table_name = self.parse_object_name()?;
self.expect_keyword(Keyword::SET)?;
let assignments = self.parse_comma_separated(Parser::parse_assignment)?;
let selection = if self.parse_keyword(Keyword::WHERE) {
Some(self.parse_expr()?)
} else {
None
};
Ok(Statement::Update {
table_name,
assignments,
selection,
})
}
pub fn parse_assignment(&mut self) -> Result<Assignment, ParserError> {
let id = self.parse_identifier()?;
self.expect_token(&Token::Eq)?;
let value = self.parse_expr()?;
Ok(Assignment { id, value })
}
pub fn parse_optional_args(&mut self) -> Result<Vec<Expr>, ParserError> {
if self.consume_token(&Token::RParen) {
Ok(vec![])
} else {
let args = self.parse_comma_separated(Parser::parse_expr)?;
self.expect_token(&Token::RParen)?;
Ok(args)
}
}
pub fn parse_select_item(&mut self) -> Result<SelectItem, ParserError> {
let expr = self.parse_expr()?;
if let Expr::Wildcard = expr {
Ok(SelectItem::Wildcard)
} else if let Expr::QualifiedWildcard(prefix) = expr {
Ok(SelectItem::QualifiedWildcard(ObjectName(prefix)))
} else {
if let Some(alias) = self.parse_optional_alias(keywords::RESERVED_FOR_COLUMN_ALIAS)? {
Ok(SelectItem::ExprWithAlias { expr, alias })
} else {
Ok(SelectItem::UnnamedExpr(expr))
}
}
}
pub fn parse_order_by_expr(&mut self) -> Result<OrderByExpr, ParserError> {
let expr = self.parse_expr()?;
let asc = if self.parse_keyword(Keyword::ASC) {
Some(true)
} else if self.parse_keyword(Keyword::DESC) {
Some(false)
} else {
None
};
let nulls_first = if self.parse_keywords(&[Keyword::NULLS, Keyword::FIRST]) {
Some(true)
} else if self.parse_keywords(&[Keyword::NULLS, Keyword::LAST]) {
Some(false)
} else {
None
};
Ok(OrderByExpr {
expr,
asc,
nulls_first,
})
}
pub fn parse_top(&mut self) -> Result<Top, ParserError> {
let quantity = if self.consume_token(&Token::LParen) {
let quantity = self.parse_expr()?;
self.expect_token(&Token::RParen)?;
Some(quantity)
} else {
Some(Expr::Value(self.parse_number_value()?))
};
let percent = self.parse_keyword(Keyword::PERCENT);
let with_ties = self.parse_keywords(&[Keyword::WITH, Keyword::TIES]);
Ok(Top {
with_ties,
percent,
quantity,
})
}
pub fn parse_limit(&mut self) -> Result<Option<Expr>, ParserError> {
if self.parse_keyword(Keyword::ALL) {
Ok(None)
} else {
Ok(Some(Expr::Value(self.parse_number_value()?)))
}
}
pub fn parse_offset(&mut self) -> Result<Offset, ParserError> {
let value = Expr::Value(self.parse_number_value()?);
let rows = if self.parse_keyword(Keyword::ROW) {
OffsetRows::Row
} else if self.parse_keyword(Keyword::ROWS) {
OffsetRows::Rows
} else {
OffsetRows::None
};
Ok(Offset { value, rows })
}
pub fn parse_fetch(&mut self) -> Result<Fetch, ParserError> {
self.expect_one_of_keywords(&[Keyword::FIRST, Keyword::NEXT])?;
let (quantity, percent) = if self
.parse_one_of_keywords(&[Keyword::ROW, Keyword::ROWS])
.is_some()
{
(None, false)
} else {
let quantity = Expr::Value(self.parse_value()?);
let percent = self.parse_keyword(Keyword::PERCENT);
self.expect_one_of_keywords(&[Keyword::ROW, Keyword::ROWS])?;
(Some(quantity), percent)
};
let with_ties = if self.parse_keyword(Keyword::ONLY) {
false
} else if self.parse_keywords(&[Keyword::WITH, Keyword::TIES]) {
true
} else {
return self.expected("one of ONLY or WITH TIES", self.peek_token());
};
Ok(Fetch {
with_ties,
percent,
quantity,
})
}
pub fn parse_values(&mut self) -> Result<Values, ParserError> {
let values = self.parse_comma_separated(|parser| {
parser.expect_token(&Token::LParen)?;
let exprs = parser.parse_comma_separated(Parser::parse_expr)?;
parser.expect_token(&Token::RParen)?;
Ok(exprs)
})?;
Ok(Values(values))
}
pub fn parse_start_transaction(&mut self) -> Result<Statement, ParserError> {
self.expect_keyword(Keyword::TRANSACTION)?;
Ok(Statement::StartTransaction {
modes: self.parse_transaction_modes()?,
})
}
pub fn parse_begin(&mut self) -> Result<Statement, ParserError> {
let _ = self.parse_one_of_keywords(&[Keyword::TRANSACTION, Keyword::WORK]);
Ok(Statement::StartTransaction {
modes: self.parse_transaction_modes()?,
})
}
pub fn parse_transaction_modes(&mut self) -> Result<Vec<TransactionMode>, ParserError> {
let mut modes = vec![];
let mut required = false;
loop {
let mode = if self.parse_keywords(&[Keyword::ISOLATION, Keyword::LEVEL]) {
let iso_level = if self.parse_keywords(&[Keyword::READ, Keyword::UNCOMMITTED]) {
TransactionIsolationLevel::ReadUncommitted
} else if self.parse_keywords(&[Keyword::READ, Keyword::COMMITTED]) {
TransactionIsolationLevel::ReadCommitted
} else if self.parse_keywords(&[Keyword::REPEATABLE, Keyword::READ]) {
TransactionIsolationLevel::RepeatableRead
} else if self.parse_keyword(Keyword::SERIALIZABLE) {
TransactionIsolationLevel::Serializable
} else {
self.expected("isolation level", self.peek_token())?
};
TransactionMode::IsolationLevel(iso_level)
} else if self.parse_keywords(&[Keyword::READ, Keyword::ONLY]) {
TransactionMode::AccessMode(TransactionAccessMode::ReadOnly)
} else if self.parse_keywords(&[Keyword::READ, Keyword::WRITE]) {
TransactionMode::AccessMode(TransactionAccessMode::ReadWrite)
} else if required {
self.expected("transaction mode", self.peek_token())?
} else {
break;
};
modes.push(mode);
required = self.consume_token(&Token::Comma);
}
Ok(modes)
}
pub fn parse_commit(&mut self) -> Result<Statement, ParserError> {
Ok(Statement::Commit {
chain: self.parse_commit_rollback_chain()?,
})
}
pub fn parse_rollback(&mut self) -> Result<Statement, ParserError> {
Ok(Statement::Rollback {
chain: self.parse_commit_rollback_chain()?,
})
}
pub fn parse_commit_rollback_chain(&mut self) -> Result<bool, ParserError> {
let _ = self.parse_one_of_keywords(&[Keyword::TRANSACTION, Keyword::WORK]);
if self.parse_keyword(Keyword::AND) {
let chain = !self.parse_keyword(Keyword::NO);
self.expect_keyword(Keyword::CHAIN)?;
Ok(chain)
} else {
Ok(false)
}
}
}
impl Word {
pub fn to_ident(&self) -> Ident {
Ident {
value: self.value.clone(),
quote_style: self.quote_style,
}
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::test_utils::all_dialects;
#[test]
fn test_prev_index() {
let sql = "SELECT version";
all_dialects().run_parser_method(sql, |parser| {
assert_eq!(parser.peek_token(), Token::make_keyword("SELECT"));
assert_eq!(parser.next_token(), Token::make_keyword("SELECT"));
parser.prev_token();
assert_eq!(parser.next_token(), Token::make_keyword("SELECT"));
assert_eq!(parser.next_token(), Token::make_word("version", None));
parser.prev_token();
assert_eq!(parser.peek_token(), Token::make_word("version", None));
assert_eq!(parser.next_token(), Token::make_word("version", None));
assert_eq!(parser.peek_token(), Token::EOF);
parser.prev_token();
assert_eq!(parser.next_token(), Token::make_word("version", None));
assert_eq!(parser.next_token(), Token::EOF);
assert_eq!(parser.next_token(), Token::EOF);
parser.prev_token();
});
}
}