Macro params

macro_rules! params {
    ( $( $x1:expr $( => $x2:expr )? ),* $(,)? ) => { ... };
}

Creates a parameter list.

This can be used for either positional parameters, named parameters, or mixing both.

The syntax is as follows:

params!(
    // Positional arguments
    1, 2, 3, 4, 5,
    // Named arguments
    "name" => "Jeremy", "age" => 50,
)

Using parameters

Every parameter, including named parameters, has a position, starting at 1.

Inside the SQL query, you can reference parameters positionally either by using the ? token, which references the next parameter, or the ?NNN token, where NNN is the parameter position.

You can also reference parameters by name. This can be done using either a : prefix (:parameter), a @ prefix (@parameter) or a $ prefix ($parameter).

When using params! with named arguments, you should include the @ or $ prefix in the parameter name. Including the : prefix is optional: the library will automatically add it if the other two are not found.

See also the SQLite documentation.

Example

async fn insert_user_data(
    connection: &mut asqlite::Connection,
    name: String,
    email: String,
) -> asqlite::Result<()> {
    connection
        .insert(
            "INSERT INTO users (name, email) VALUES (?, :email)",
            asqlite::params!(name, "email" => email),
        )
        .await?;
    Ok(())
}