CAST and CONVERT()

Signature

CAST ( expression AS data_type [ ( length ) ] )

Parameters

• expression — Any valid expression.
• data_type — The target data type. This includes xml, bigint, and sql_variant. Alias data types can't be used.
• length — An optional integer that specifies the length of the target data type, for data types that allow a user specified length. The default value is 30.
• style — An integer expression that specifies how the `CONVERT` function will translate *expression*. For a style value of NULL, NULL is returned. *data_type* determines the range.

Examples

SELECT CAST(CAST(0x41 AS nvarchar) AS varbinary);

0x4100

SELECT CAST('abc' AS varchar(5)) COLLATE French_CS_AS;

abc

SELECT CAST(10.6496 AS INT) AS trunc1,
       CAST(-10.6496 AS INT) AS trunc2,
       CAST(10.6496 AS NUMERIC) AS round1,
       CAST(-10.6496 AS NUMERIC) AS round2;

10|-10|11|-11

Run against SQL Server 16.0.4265.3 on 2026-09-13. This is the output we got, not the documentation’s.

Available on

• SQL Server 2017 and later
• Azure SQL Database
• Azure SQL Managed Instance
• Azure Synapse Analytics
• Analytics Platform System (PDW)
• Microsoft Fabric warehouse
• Fabric SQL database