Learn to manage data with INSERT, UPDATE, DELETE.
Data Manipulation Language (DML) is the subset of SQL commands used to manage the actual data stored within database objects. While DDL builds the container, DML fills it up, modifies its contents, and removes them. The core DML commands are `INSERT`, `UPDATE`, and `DELETE`. The `INSERT` command is used to add new rows of data into a table. You specify the table name and the values for each column. For example, `INSERT INTO students (id, name) VALUES (1, 'Alice');` adds a new record to the 'students' table. The `UPDATE` command is used to modify existing records in a table. It is almost always used with a `WHERE` clause to specify which row(s) to change. Forgetting the `WHERE` clause will cause the command to update every single row in the table. For example, `UPDATE students SET major = 'History' WHERE id = 1;` changes the major for the student with ID 1. The `DELETE` command is used to remove existing records from a table. Similar to `UPDATE`, it requires a `WHERE` clause to specify which rows to delete. `DELETE FROM students WHERE id = 1;` removes the student with ID 1. If the `WHERE` clause is omitted, all records in the table will be deleted. These three commands are the foundation of day-to-day database operations for any application.