ISNUMERIC function in SQL Server:
The ISNUMERIC function determines whether an expression is a valid numeric type.
It is a scalar function that takes a string expression as a parameter and returns an integer.
If the input expression is evaluated to a valid numeric data type, SQL Server ISNUMERIC returns 1;
otherwise, it returns 0.
A valid numeric data type is one of the following types: bit, tinyint, smallint, int, bigint, decimal, numeric, float, real, money, smallmoney.
Example:
CREATE TABLE [employee](
[empid] [varchar](50) NULL,
[emp_name] [nvarchar](100) NULL,
[salary] [float] NULL
) ON [PRIMARY]
select ISNUMERIC(salary),ISNUMERIC(empid) from employee;
scalar function:
The user-defined function which returns only a single value (scalar value) is known as the Scalar Valued Function.
Scalar Value Functions in SQL Server may or may not have parameters that are optional but always return a single (scalar) value which is mandatory.
