Struct toql::sql_expr::SqlExpr

pub struct SqlExpr { /* private fields */ }

A SQL expression is a list of tokens that can be resolved into SQL.

Library users are advised to not build it programmatically, but to use the sql_expr! macro. This macro provides compile time safety and convenience.

However it’s also possible to build it programmatically:

Example

 use toql_core::sql_expr::SqlExpr;

 let mut e = SqlExpr::literal("SELECT ");
 e.push_self_alias();
 e.push_literal("id FROM User ");
 e.push_self_alias();

 assert_eq!("SELECT ..id FROM User ..", e.to_string());

The resolver will replace the self aliases into real aliases and build proper SQL.

Implementations

impl SqlExpr

pub fn from(tokens: Vec<SqlExprToken, Global>) -> SqlExpr

Create SQL expression from token list.

pub fn new() -> SqlExpr

Create new empty SQL expression.

pub fn literal(lit: impl Into<String>) -> SqlExpr

Create SQL expression from literal.

pub fn alias(lit: impl Into<String>) -> SqlExpr

Create SQL expression from alias.

pub fn self_alias() -> SqlExpr

Create SQL expression from self alias.

pub fn other_alias() -> SqlExpr

Create SQL expression from other alias.

pub fn unresolved_arg() -> SqlExpr

Create SQL expression from unresolved argument.

pub fn arg(a: SqlArg) -> SqlExpr

Create SQL expression from argument.

pub fn aliased_column(column_name: impl Into<String>) -> SqlExpr

Create SQL expression from aliased column.

pub fn push_literal(&mut self, lit: impl Into<String>) -> &mut SqlExpr

Add literal at the end of token list.

pub fn pop_literals(&mut self, count: usize) -> &mut SqlExpr

Remove a number of characters -or less- from the end of the list. This affects only the last (literal) token.

pub fn ends_with_literal(&self, lit: &str) -> bool

Return true if last literal token ends with lit.

pub fn pop(&mut self) -> &mut SqlExpr

Remove last token from list.

pub fn push_self_alias(&mut self) -> &mut SqlExpr

Add self alias to the end of the list.

pub fn push_other_alias(&mut self) -> &mut SqlExpr

Add other alias to the end of the list.

pub fn push_alias(&mut self, alias: impl Into<String>) -> &mut SqlExpr

Add custom alias to the end of the list.

pub fn push_arg(&mut self, arg: SqlArg) -> &mut SqlExpr

Add argument to the end of the list.

pub fn push_unresolved_arg(&mut self) -> &mut SqlExpr

Add unresolved argument to the end of the list.

pub fn is_empty(&self) -> bool

Returns true, if list is empty.

pub fn first_aux_param(&self) -> Option<&String>

Returns first auxiliary parameter, if any.

pub fn push_predicate(
    &mut self,
    columns: Vec<PredicateColumn, Global>,
    args: Vec<SqlArg, Global>
) -> &mut SqlExpr

Add a predicate to the end of the list.

pub fn extend(&mut self, expr: impl Into<SqlExpr>) -> &mut SqlExpr

Add another SQL expression to the end of the list.

pub fn tokens(&self) -> &[SqlExprToken]

Trait Implementations

impl Clone for SqlExpr

fn clone(&self) -> SqlExpr

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SqlExpr

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for SqlExpr

fn default() -> SqlExpr

Returns the “default value” for a type.

impl Display for SqlExpr

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<'_> From<&'_ String> for SqlExpr

fn from(s: &String) -> SqlExpr

Converts to this type from the input type.

impl<'_> From<&'_ str> for SqlExpr

fn from(s: &str) -> SqlExpr

Converts to this type from the input type.

impl From<String> for SqlExpr

fn from(s: String) -> SqlExpr

Converts to this type from the input type.