sea_query/backend/
index_builder.rs

1use crate::*;
2
3pub trait IndexBuilder: QuotedBuilder + TableRefBuilder {
4    /// Translate [`IndexCreateStatement`] into SQL expression.
5    /// This is the default implementation for `PostgresQueryBuilder` and `SqliteQueryBuilder`.
6    /// `MysqlQueryBuilder` overrides this default implementation.
7    fn prepare_table_index_expression(
8        &self,
9        create: &IndexCreateStatement,
10        sql: &mut dyn SqlWriter,
11    ) {
12        if let Some(name) = &create.index.name {
13            write!(
14                sql,
15                "CONSTRAINT {}{}{} ",
16                self.quote().left(),
17                name,
18                self.quote().right()
19            )
20            .unwrap();
21        }
22
23        self.prepare_index_prefix(create, sql);
24
25        self.prepare_index_columns(&create.index.columns, sql);
26
27        self.prepare_filter(&create.r#where, sql);
28    }
29
30    /// Translate [`IndexCreateStatement`] into SQL statement.
31    fn prepare_index_create_statement(
32        &self,
33        create: &IndexCreateStatement,
34        sql: &mut dyn SqlWriter,
35    );
36
37    /// Translate [`TableRef`] into SQL statement.
38    fn prepare_table_ref_index_stmt(&self, table_ref: &TableRef, sql: &mut dyn SqlWriter);
39
40    /// Translate [`IndexDropStatement`] into SQL statement.
41    fn prepare_index_drop_statement(&self, drop: &IndexDropStatement, sql: &mut dyn SqlWriter);
42
43    #[doc(hidden)]
44    /// Write the index type (Btree, hash, ...).
45    fn prepare_index_type(&self, _col_index_type: &Option<IndexType>, _sql: &mut dyn SqlWriter) {}
46
47    #[doc(hidden)]
48    /// Write the index prefix (primary, unique, ...).
49    fn prepare_index_prefix(&self, create: &IndexCreateStatement, sql: &mut dyn SqlWriter);
50
51    #[doc(hidden)]
52    /// Write the column index prefix.
53    fn write_column_index_prefix(&self, col_prefix: &Option<u32>, sql: &mut dyn SqlWriter) {
54        if let Some(prefix) = col_prefix {
55            write!(sql, " ({prefix})").unwrap();
56        }
57    }
58
59    #[doc(hidden)]
60    /// Write the column index prefix.
61    fn prepare_index_columns(&self, columns: &[IndexColumn], sql: &mut dyn SqlWriter) {
62        write!(sql, "(").unwrap();
63        columns.iter().fold(true, |first, col| {
64            if !first {
65                write!(sql, ", ").unwrap();
66            }
67            col.name.prepare(sql.as_writer(), self.quote());
68            self.write_column_index_prefix(&col.prefix, sql);
69            if let Some(order) = &col.order {
70                match order {
71                    IndexOrder::Asc => write!(sql, " ASC").unwrap(),
72                    IndexOrder::Desc => write!(sql, " DESC").unwrap(),
73                }
74            }
75            false
76        });
77        write!(sql, ")").unwrap();
78    }
79
80    #[doc(hidden)]
81    // Write WHERE clause for partial index. This function is not available in MySQL.
82    fn prepare_filter(&self, _condition: &ConditionHolder, _sql: &mut dyn SqlWriter) {}
83}
sea_query/backend/index_builder.rs

sea_query/backend/
index_builder.rs
