bit (Transact-SQL)

Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW) SQL analytics endpoint in Microsoft Fabric Warehouse in Microsoft Fabric

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


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 bit data type can be used to store Boolean values. 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.