ISNUMERIC (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

Determines whether an expression is a valid numeric type.

Transact-SQL syntax conventions

ISNUMERIC ( expression )

The expression to be evaluated.

int

ISNUMERIC returns 1 when the input expression evaluates to a valid numeric data type; otherwise it returns 0. Valid numeric data types include the following items:

ISNUMERIC returns 1 for some characters that aren't numbers, such as plus (+), minus (-), and valid currency symbols such as the dollar sign ($). For a complete list of currency symbols, see money and smallmoney (Transact-SQL).

The following example uses ISNUMERIC to return all the postal codes that aren't numeric values.

USE AdventureWorks2022;
GO

SELECT City,
    PostalCode
FROM Person.Address
WHERE ISNUMERIC(PostalCode) <> 1;
GO

The following example uses ISNUMERIC to return whether the database name and ID are numeric values.

USE master;
GO

SELECT name,
    ISNUMERIC(name) AS IsNameANumber,
    database_id,
    ISNUMERIC(database_id) AS IsIdANumber
FROM sys.databases;
GO

• Expressions (Transact-SQL)
• System Functions by category for Transact-SQL
• Data types (Transact-SQL)