ISNUMERIC SQL Server

SQL Server > Built-In Functions > ISNUMERIC

ISNUMERIC returns 1 when the input expression evaluates to a valid numeric data type; otherwise it returns 0

Example:

IF OBJECT_ID(N'tbl1', N'U') IS NOT NULL

       DROP TABLE tbl1;
GO

CREATE TABLE tbl1

(
       id     int ,
       code   varchar(50)
);
GO

INSERT INTO tbl1 values  (1,'aaa'), (2,'b12') , (3,'345')

SELECT
       *
FROM
       tbl1
WHERE
       ISNUMERIC(code) = 1

Result:

 

id code
3  345