nodedb-sql 0.0.0-beta.5

SQL parser, planner, and optimizer for NodeDB
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42

//! SQL parsing via sqlparser-rs.

use sqlparser::ast::Statement;
use sqlparser::dialect::PostgreSqlDialect;
use sqlparser::parser::Parser;

use crate::error::{Result, SqlError};

/// Parse a SQL string into one or more statements.
pub fn parse_sql(sql: &str) -> Result<Vec<Statement>> {
    let dialect = PostgreSqlDialect {};
    let statements = Parser::parse_sql(&dialect, sql)?;
    if statements.is_empty() {
        return Err(SqlError::Parse {
            detail: "empty SQL statement".into(),
        });
    }
    Ok(statements)
}

/// Classify a parsed statement for routing.
#[derive(Debug)]
pub enum StatementKind<'a> {
    Select(&'a sqlparser::ast::Query),
    Insert(&'a sqlparser::ast::Insert),
    Update(&'a sqlparser::ast::Statement),
    Delete(&'a sqlparser::ast::Statement),
    Truncate(&'a sqlparser::ast::Statement),
    Other,
}

/// Classify a parsed statement.
pub fn classify(stmt: &Statement) -> StatementKind<'_> {
    match stmt {
        Statement::Query(q) => StatementKind::Select(q),
        Statement::Insert(ins) => StatementKind::Insert(ins),
        Statement::Update(_) => StatementKind::Update(stmt),
        Statement::Delete(_) => StatementKind::Delete(stmt),
        Statement::Truncate(_) => StatementKind::Truncate(stmt),
        _ => StatementKind::Other,
    }
}