diesel/pg/query_builder/
mod.rs

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1use super::backend::Pg;
2use crate::query_builder::QueryBuilder;
3use crate::result::QueryResult;
4
5pub(crate) mod copy;
6mod distinct_on;
7mod limit_offset;
8pub(crate) mod on_constraint;
9pub(crate) mod only;
10mod query_fragment_impls;
11pub(crate) mod tablesample;
12pub use self::copy::{CopyFormat, CopyFromQuery, CopyHeader, CopyTarget, CopyToQuery};
13pub use self::distinct_on::DistinctOnClause;
14pub use self::distinct_on::OrderDecorator;
15
16/// The PostgreSQL query builder
17#[allow(missing_debug_implementations)]
18#[derive(Default)]
19#[cfg(feature = "postgres_backend")]
20pub struct PgQueryBuilder {
21    sql: String,
22    bind_idx: u32,
23}
24
25impl PgQueryBuilder {
26    /// Constructs a new query builder with an empty query
27    pub fn new() -> Self {
28        PgQueryBuilder::default()
29    }
30}
31
32impl QueryBuilder<Pg> for PgQueryBuilder {
33    fn push_sql(&mut self, sql: &str) {
34        self.sql.push_str(sql);
35    }
36
37    fn push_identifier(&mut self, identifier: &str) -> QueryResult<()> {
38        self.push_sql("\"");
39        self.push_sql(&identifier.replace('"', "\"\""));
40        self.push_sql("\"");
41        Ok(())
42    }
43
44    fn push_bind_param(&mut self) {
45        self.push_bind_param_value_only();
46        self.sql += "$";
47        let mut buffer = itoa::Buffer::new();
48        self.sql += buffer.format(self.bind_idx);
49    }
50
51    fn push_bind_param_value_only(&mut self) {
52        self.bind_idx += 1;
53    }
54
55    fn finish(self) -> String {
56        self.sql
57    }
58}
59
60#[cfg(test)]
61#[diesel_test_helper::test]
62fn check_sql_query_increments_bind_count() {
63    use crate::query_builder::{AstPass, AstPassToSqlOptions, QueryFragment};
64    use crate::sql_types::*;
65
66    let query = crate::sql_query("SELECT $1, $2, $3")
67        .bind::<Integer, _>(42)
68        .bind::<Integer, _>(3)
69        .bind::<Integer, _>(342);
70
71    let mut query_builder = PgQueryBuilder::default();
72
73    {
74        let mut options = AstPassToSqlOptions::default();
75        let ast_pass = AstPass::<crate::pg::Pg>::to_sql(&mut query_builder, &mut options, &Pg);
76
77        query.walk_ast(ast_pass).unwrap();
78    }
79
80    assert_eq!(query_builder.bind_idx, 3);
81    assert_eq!(query_builder.sql, "SELECT $1, $2, $3");
82}
diesel/pg/query_builder/mod.rs

diesel/pg/query_builder/
mod.rs
