Derive Macro DeleteTemplate

#[derive(DeleteTemplate)]
{
    // Attributes available to this derive:
    #[table_name]
    #[tp_delete]
    #[debug_slow]
}

DeleteTemplate is a derive macro designed to automatically generate record deletion functions based on sqlx. This macro creates delete methods for the struct it is applied to, returning the number of records deleted. It assumes that the columns in the database correspond to the fields in the struct.

Attributes

DeleteTemplate accepts the following attributes:

• table_name: Specifies the name of the table in the database (mandatory).
• debug_slow: Configures debug logs for the executed query:
  • If set to 0: Only logs the executed query.
  • If set to a value greater than 0: Only logs the query if the execution time exceeds the configured value (in milliseconds).
  • If not configured, no debug logs will be generated.
• tp_delete: The main configuration for generating the delete function, with the following sub-attributes:
  • by: List of columns that will be the delete condition, will be the function’s input (mandatory and non-empty).
  • fn_name: The name of the generated function. If empty, the library will automatically generate a function name.
  • returning: If set to true, the generated function will return the deleted record (only enabled with the postgres feature).
  • debug_slow: Configures debug logs for the executed query:
    • If set to 0: Only logs the executed query.
    • If set to a value greater than 0: Only logs the query if the execution time exceeds the configured value (in milliseconds).
    • If not configured, no debug logs will be generated.

The debug_slow attribute at the struct level has priority over the value in tp_delete.

Example

use sqlx_template::DeleteTemplate;

#[derive(DeleteTemplate, sqlx::FromRow)]
#[table_name = "users"]
#[tp_delete(by = "id", fn_name = "delete_user", returning = true)]
#[tp_delete(by = "id")]
pub struct User {
    pub id: i32,
    pub email: String,
    pub password: String,
}

// Delete a user record by id
let user = User { id: 1, email: "john.doe@example.com".to_string(), password: "password123".to_string() };
let rows_affected = User::delete_by_id(&user.id, &pool).await?;
println!("Rows affected: {}", rows_affected);

// If the `postgres` feature is enabled and `returning` is set to true
#[cfg(feature = "postgres")]
let deleted_user = User::delete_user(&user.id, &pool).await?;
println!("Deleted user: {:?}", deleted_user);

In the example above:

• table_name is set to “users”, specifying the table to delete from.
• The first tp_delete generates a function named delete_user to delete a record based on the id column and return the deleted record (with the postgres feature enabled).
• debug_slow is set to 1000 milliseconds, meaning only queries taking longer than 1 second will be logged for debugging.

Note

This macro relies on sqlx, so you need to add sqlx to your [dependencies] in Cargo.toml and properly configure the database connection before using the generated delete methods.