(mysql) LIKE for non-text columns

[RazrFalcon]

I there a way to use LIKE statement for any column? Currently, it tied to TextExpressionMethods. But MySQL works fine with any column type.

PS: I need this to fuzzy search in DECIMAL column.

[sgrif]

See http://diesel.rs/guides/extending-diesel/#custom-operators for examples of how to add new operators to Diesel

[RazrFalcon]

Thanks.

I've tried this:

diesel_infix_operator!(MyLike, " LIKE ");

pub trait MyLikeMethods: Expression + Sized {
    fn my_like<T: AsExpression<Self::SqlType>>(self, rhs: T) -> MyLike<Self, T::Expression> {
        MyLike::new(self, rhs.as_expression())
    }
}

impl<T: Expression> MyLikeMethods for T {}

{
    let some_text = "some text".to_string();
    let list: Vec<MyStruct> = table::my_table
        .filter(columns::my_table::price.my_like(format!("%{}%", some_text)))
        .load(conn)?;
}

But I'm getting:

error[E0277]: the trait bound `std::string::String: diesel::Expression` is not satisfied
   --> src/db/invoices.rs:253:48
    |
253 |         .filter(columns::invoices::total_price.my_like(format!("%{}%", some_text)))
    |                                                ^^^^^^^ the trait `diesel::Expression` is not implemented for `std::string::String`
    |
    = note: required because of the requirements on the impl of `diesel::expression::AsExpression<diesel::sql_types::Numeric>` for `std::string::String`

The price column is Decimal.

[sgrif]

You defined my_like to exist on all types, and take any argument of the same type. It sounds like you want it to be only on decimal columns, and only take text arguments. You should write fn my_like<T: AsExpression<Text>> and impl<T: Expression<SqlType = Decimal>>

[RazrFalcon]

Thanks! It worked.