Transact-SQL Reference

Transact-SQL (T-SQL) is Microsoft's procedural extension of SQL, the standard language for relational database management. T-SQL adds procedural programming, local variables, command processing functions, and other programming constructs to SQL.

Getting Started

Learn the fundamentals of T-SQL, including basic syntax, data manipulation, and querying.

Key Components

Explore the core elements of Transact-SQL.

Data Types

Understand the various data types available in T-SQL for storing different kinds of information.

Common data types include:

INT, BIGINT, SMALLINT, TINYINT
VARCHAR(n), NVARCHAR(n)
DECIMAL(p,s), NUMERIC(p,s)
DATE, DATETIME, DATETIME2
BIT

See the full Data Types section for details.

Statements

T-SQL provides a rich set of statements for managing and querying databases.

Key statements include:

SELECT: Retrieve data from a database.
INSERT: Add new rows to a table.
UPDATE: Modify existing data in a table.
DELETE: Remove rows from a table.
CREATE TABLE: Define new tables.
ALTER TABLE: Modify existing table structures.
DROP TABLE: Remove tables from the database.
CREATE PROCEDURE: Define stored procedures.
CREATE TRIGGER: Define triggers.

Browse all Statements.

Functions

T-SQL offers built-in functions for performing calculations, manipulating strings, dates, and more.

Examples of common functions:

String Functions: LEN(), SUBSTRING(), UPPER(), LOWER()
Date Functions: GETDATE(), DATEADD(), DATEDIFF()
Aggregate Functions: SUM(), AVG(), COUNT(), MAX(), MIN()
System Functions: DB_NAME(), USER_NAME()

Explore the complete list of Functions.

Advanced Topics

Learn More

For deeper insights and best practices, check out these resources: