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 less 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.
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)
SET @local_variable (Transact-SQL)