How to Use IF Statement in SQL

The SQL IF statement lets you run conditional logic directly in the database engine. It evaluates a Boolean expression and executes one code block when true and, optionally, another when false.

What Is the SQL IF Statement?

SQL IF is a procedural flow-control command available in T-SQL (SQL Server), MySQL, Snowflake, and other dialects. It is not part of the ANSI SQL standard, so syntax differs slightly by platform.

When Should I Use IF in SQL?

Use IF to validate parameters, branch execution paths, enforce business rules, or raise custom errors inside stored procedures, user-defined functions, or ad-hoc scripts.

What Is the Basic Syntax of IF?

The core pattern is IF <boolean_expression> statement; or with an alternative branch IF <expr> statement; ELSE statement;. Multiple statements are wrapped in BEGIN and END blocks.

Simple Example of IF

This example prints a message only when the total exceeds 100:

IF (@total > 100)
PRINT 'High total';

Using IF...ELSE

Add an ELSE block to handle the false condition:

IF (@total > 100)
PRINT 'High';
ELSE
PRINT 'Normal';

Using IF with BEGIN...END Blocks

Wrap multiple statements in a block so they act as one unit:

IF (@IsActive = 1)
BEGIN
UPDATE Users SET LastLogin = GETDATE() WHERE Id = @UserId;
INSERT INTO Log (Info) VALUES ('Login recorded');
END;

Can I Use IF Inside Stored Procedures?

Yes. IF often lives inside stored procedures to decide which queries run. It can exit early with RETURN or raise an error with THROW/RAISERROR.

How Do I Combine Multiple Conditions?

Combine Boolean expressions with AND and OR, or nest IF statements for complex branching. For row-level logic inside SELECT, use the CASE expression instead.

How Does IF Differ from CASE?

IF controls statement flow, executing or skipping entire blocks. CASE is an expression that returns a value per row. Use IF for procedural branching; use CASE for set-based column logic.

Best Practices for SQL IF

Keep conditions simple and index-friendly, comment business rules, and prefer CASE in queries to avoid RBAR (row-by-row) patterns. Always wrap multi-statement blocks in BEGIN...END.

Key Takeaways on SQL IF Statement

SQL IF provides server-side conditional execution. Master its syntax, use ELSE wisely, favor CASE for row logic, and follow best practices to write clear, maintainable T-SQL.