Function delete

pub fn delete<T: SqlCommand + SqlParams>(
    conn: &Connection,
    entity: T,
) -> Result<usize, Error>

delete

Deletes a record from the database.

Parameters

• conn: SQLite database connection
• entity: Data object containing deletion parameters (must implement SqlCommand and SqlParams traits)

Return Value

• Result<usize, Error>: On success, returns the number of deleted records; on failure, returns Error

Struct Definition

Structs used with this function should be annotated with the following derive macros:

#[derive(Deletable, SqlParams)]   // Required macros
#[table("table_name")]            // Table name to delete from
#[where_clause("id = ?")]         // Delete condition
pub struct MyEntity {
    pub id: i64,                  // Field used in the condition
}

• Deletable: Automatically generates SQL DELETE statements
• SqlParams: Automatically generates SQL parameters
• #[table("table_name")]: Specifies the table name for the deletion
• #[where_clause("id = ?")]: Specifies the delete condition (? will be replaced with parameter value)

Example Usage

use rusqlite::{Connection, Result};
use parsql_macros::{Deletable, SqlParams};
use parsql_sqlite::delete;

fn main() -> Result<()> {
    // Create database connection
    let conn = Connection::open("test.db")?;
    conn.execute("CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT, email TEXT)", [])?;
    conn.execute("INSERT INTO users (id, name, email) VALUES (1, 'John', 'john@example.com')", [])?;

    // Define a delete query
    #[derive(Deletable, SqlParams)]
    #[table("users")]
    #[where_clause("id = ?")]
    pub struct DeleteUser {
        pub id: i64,
    }

    // Create delete parameters (delete user with ID 1)
    let delete_query = DeleteUser { id: 1 };

    // Execute delete
    let delete_result = delete(&conn, delete_query)?;
    println!("Delete result: {:?}", delete_result);
    Ok(())
}