Trait diesel::pg::expression::expression_methods::ArrayExpressionMethods
postgres
[−] [src]

pub trait ArrayExpressionMethods<ST>: Expression<SqlType = Array<ST>> + Sized {
    fn overlaps_with<T>(self, other: T) -> OverlapsWith<Self, T::Expression>
    where
        T: AsExpression<Self::SqlType>,
    { ... }

    fn contains<T>(self, other: T) -> Contains<Self, T::Expression>
    where
        T: AsExpression<Self::SqlType>,
    { ... }

    fn is_contained_by<T>(self, other: T) -> IsContainedBy<Self, T::Expression>
    where
        T: AsExpression<Self::SqlType>,
    { ... }
}

Provided Methods

Compares two arrays for common elements, using the && operator in the final SQL

Example

diesel::insert(&vec![
    NewPost { tags: vec!["cool", "awesome"] },
    NewPost { tags: vec!["awesome", "great"] },
    NewPost { tags: vec!["cool", "great"] },
]).into(posts).execute(&conn).unwrap();

let query = posts.select(id).filter(tags.overlaps_with(vec!["horrid", "cool"]));
assert_eq!(Ok(vec![1, 3]), query.load(&conn));

let query = posts.select(id).filter(tags.overlaps_with(vec!["cool", "great"]));
assert_eq!(Ok(vec![1, 2, 3]), query.load(&conn));

let query = posts.select(id).filter(tags.overlaps_with(vec!["horrid"]));
assert_eq!(Ok(Vec::new()), query.load::<i32>(&conn));

Compares whether an array contains another array, using the @> operator.

Example

diesel::insert(&vec![
    NewPost { tags: vec!["cool", "awesome"] },
]).into(posts).execute(&conn).unwrap();

let query = posts.select(id).filter(tags.contains(vec!["cool"]));
assert_eq!(Ok(vec![1]), query.load(&conn));

let query = posts.select(id).filter(tags.contains(vec!["cool", "amazing"]));
assert_eq!(Ok(Vec::new()), query.load::<i32>(&conn));

Compares whether an array is contained by another array, using the <@ operator. This is the opposite of contains

Example

diesel::insert(&vec![
    NewPost { tags: vec!["cool", "awesome"] },
]).into(posts).execute(&conn).unwrap();

let query = posts.select(id).filter(tags.is_contained_by(vec!["cool", "awesome", "amazing"]));
assert_eq!(Ok(vec![1]), query.load(&conn));

let query = posts.select(id).filter(tags.is_contained_by(vec!["cool"]));
assert_eq!(Ok(Vec::new()), query.load::<i32>(&conn));

Implementors