sea_orm/query/
traits.rs

1use crate::{ColumnAsExpr, ColumnTrait, DbBackend, IntoIdentity, QuerySelect, Statement};
2use sea_query::QueryStatementBuilder;
3
4/// A Trait for any type performing queries on a Model or ActiveModel
5pub trait QueryTrait {
6    /// Constrain the QueryStatement to [QueryStatementBuilder] trait
7    type QueryStatement: QueryStatementBuilder;
8
9    /// Get a mutable ref to the query builder
10    fn query(&mut self) -> &mut Self::QueryStatement;
11
12    /// Get an immutable ref to the query builder
13    fn as_query(&self) -> &Self::QueryStatement;
14
15    /// Take ownership of the query builder
16    fn into_query(self) -> Self::QueryStatement;
17
18    /// Build the query as [`Statement`]
19    fn build(&self, db_backend: DbBackend) -> Statement {
20        let query_builder = db_backend.get_query_builder();
21        Statement::from_string_values_tuple(
22            db_backend,
23            self.as_query().build_any(query_builder.as_ref()),
24        )
25    }
26
27    /// Apply an operation on the [QueryTrait::QueryStatement] if the given `Option<T>` is `Some(_)`
28    ///
29    /// # Example
30    ///
31    /// ```
32    /// use sea_orm::{entity::*, query::*, tests_cfg::cake, DbBackend};
33    ///
34    /// assert_eq!(
35    ///     cake::Entity::find()
36    ///         .apply_if(Some(3), |mut query, v| {
37    ///             query.filter(cake::Column::Id.eq(v))
38    ///         })
39    ///         .apply_if(Some(100), QuerySelect::limit)
40    ///         .apply_if(None, QuerySelect::offset::<Option<u64>>) // no-op
41    ///         .build(DbBackend::Postgres)
42    ///         .to_string(),
43    ///     r#"SELECT "cake"."id", "cake"."name" FROM "cake" WHERE "cake"."id" = 3 LIMIT 100"#
44    /// );
45    /// ```
46    fn apply_if<T, F>(self, val: Option<T>, if_some: F) -> Self
47    where
48        Self: Sized,
49        F: FnOnce(Self, T) -> Self,
50    {
51        if let Some(val) = val {
52            if_some(self, val)
53        } else {
54            self
55        }
56    }
57}
58
59/// Select specific column for partial model queries
60pub trait SelectColumns {
61    /// Add a select column
62    ///
63    /// For more detail, please visit [QuerySelect::column]
64    fn select_column<C: ColumnTrait>(self, col: C) -> Self;
65
66    /// Add a select column with alias
67    ///
68    /// For more detail, please visit [QuerySelect::column_as]
69    fn select_column_as<C, I>(self, col: C, alias: I) -> Self
70    where
71        C: ColumnAsExpr,
72        I: IntoIdentity;
73}
74
75impl<S> SelectColumns for S
76where
77    S: QuerySelect,
78{
79    fn select_column<C: ColumnTrait>(self, col: C) -> Self {
80        QuerySelect::column(self, col)
81    }
82
83    fn select_column_as<C, I>(self, col: C, alias: I) -> Self
84    where
85        C: ColumnAsExpr,
86        I: IntoIdentity,
87    {
88        QuerySelect::column_as(self, col, alias)
89    }
90}
sea_orm/query/traits.rs

sea_orm/query/
traits.rs
