mySQL_guide.sql

-- Add new column in database which is foreign key
ALTER TABLE database.table
  ADD COLUMN columnname INT DEFAULT(1),
  ADD FOREIGN KEY fk_name(fk_column) REFERENCES reftable(refcolumn) ON DELETE CASCADE;
  
--create table
CREATE TABLE IF NOT EXISTS checklists (
    todo_id INT AUTO_INCREMENT,
    task_id INT,
    todo VARCHAR(255) NOT NULL,
    is_completed BOOLEAN NOT NULL DEFAULT FALSE,
    PRIMARY KEY (todo_id , task_id),
    FOREIGN KEY (task_id)
        REFERENCES tasks (task_id)
        ON UPDATE RESTRICT ON DELETE CASCADE
);

--change table column name
ALTER TABLE "table_name" Change "column 1" "column 2" ["Data Type"];