Sqlite NULL and unique? [closed]

Answer 1

You can create 2 triggers on table to check if a row with column as null exists before any insert or update operation, if so raise exception.

CREATE TRIGGER UniqueColumnCheckNullInsert
        BEFORE INSERT
        ON 'Tablename'
        WHEN NEW.'column_name' IS NULL
        BEGIN
        SELECT CASE WHEN((
            SELECT 1
            FROM 'Tablename'
            WHERE 'column_name' IS NULL
            )
            NOTNULL) THEN RAISE(ABORT, "error row exists") END;
    END;

CREATE TRIGGER UniqueColumnCheckNullUpdate
        BEFORE UPDATE
        ON 'Tablename'
        WHEN NEW.'column_name' IS NULL
        BEGIN
        SELECT CASE WHEN((
            SELECT 1
            FROM 'Tablename'
            WHERE 'column_name' IS NULL
            )
            NOTNULL) THEN RAISE(ABORT, "error row exists") END;
    END;