# Modifying Data in T-SQL

Modifying Data in T-SQL: Inserting Data, Updating Data, Deleting Data, Transactions.

Updated: November 3, 2026

1. [Inserting Data](https://www.ask-codey.com/lessons/modifying-data-in-t-sql-inserting-data) (Apprentice): Add rows to a table with INSERT INTO, name the columns you fill, let identity columns number new rows, and respect the table's keys.
2. [Updating Data](https://www.ask-codey.com/lessons/modifying-data-in-t-sql-updating-data) (Apprentice): Change existing rows with UPDATE ... SET, always limited by a WHERE that you've tested first with a SELECT.
3. [Deleting Data](https://www.ask-codey.com/lessons/modifying-data-in-t-sql-deleting-data) (Apprentice): Remove rows with DELETE FROM ... WHERE, test the WHERE first, and delete in the order the foreign keys allow.
4. [Transactions](https://www.ask-codey.com/lessons/modifying-data-in-t-sql-transactions) (Apprentice): Group changes into a transaction so they all happen or none do, and use ROLLBACK as a safety net while you work.

Source: https://www.ask-codey.com/courses/csharp-full-stack-bootcamp/topics/modifying-data-in-t-sql