I have a list of records that I have to insert, but I do not want duplicates to be inserted with the same fields, I need to verify if this record exists and do not insert it and continue to analyze the following

```
BEGIN
IF NOT EXISTS (SELECT * FROM Leads WHERE n_documento = new.n_documento AND programa = new.programa) THEN
    INSERT INTO Leads
    VALUES
    (NULL, new.nombres, new.apellidos, new.n_documento, new.fecha_de_nacimiento, new.telefono, new.email, new.ciudad, 
    new.pais, new.anos_de_experiencia, new.origen, new.informacion_adicional, new.fecha, new.programa, new.estado, new.fecha_charla,
    new.grado_de_estudio, new.empresa, new.cargo, null);
END IF;

```

my trigger does not work, it does not validate and it allows entering the duplicates