bit (Transact-SQL)

**APPLIES TO:** SQL Server (starting with 2008) Azure SQL Database Azure SQL Data Warehouse Parallel Data Warehouse

An integer data type that can take a value of 1, 0, or NULL.

Remarks

The SQL Server Database Engine optimizes storage of bit columns. If there are 8 or fewer bit columns in a table, the columns are stored as 1 byte. If there are from 9 up to 16 bit columns, the columns are stored as 2 bytes, and so on.

The string values TRUE and FALSE can be converted to bit values: TRUE is converted to 1 and FALSE is converted to 0.

Converting to bit promotes any nonzero value to 1.

See also

ALTER TABLE (Transact-SQL)
CAST and CONVERT (Transact-SQL)
CREATE TABLE (Transact-SQL)
Data Type Conversion (Database Engine)
Data Types (Transact-SQL)
[DECLARE @local_variable (Transact-SQL)](../../t-sql/language-elements/declare-local-variable-transact-sql.md)
[SET @local_variable (Transact-SQL)](../../t-sql/language-elements/set-local-variable-transact-sql.md)
sys.types (Transact-SQL)