The IFMISMATCHED function writes out a specified value if the input expression does not match the specified data type or typing array. Otherwise, it writes the source value. Input can be a literal, a column reference, or a function.

The ISMISMATCHED function simply tests if a value is mismatched. See ISMISMATCHED Function.

Basic data type:

ifmismatched(my_ssn,'SSN', 'XXX-XX-XXXX')

Output: Returns the value XXX-XX-XXXX if the value in my_ssn does not match the SSN data type. 

Data type with formatting options:

For data types with formatting options, such as Datetime, you can specify the format using an array, as in the following:

ifmismatched(month_Date, ['Datetime','mm-dd-yy','mm*dd*yy'], null())

Output: Returns null if values in month_Date are mismatched against Datetime values in the mm-dd-yy or mm*dd*yy formats.

ifmismatched(column_string, data_type_literal, computed_value)

ArgumentRequired?Data TypeDescription
source_valueYstringName of column, string literal or function to be tested
datatype_literalYstringString literal or array that identifies the data type against which to validate the source values
output_valueystringString literal value to write


Name of the column, string literal, or function to be tested for data type matches.

Required?Data TypeExample Value
YesString literal, column reference, or functionmyColumn


Literal value or string array that identifies data type to which to validate the source column or string.

Required?Data TypeExample Value
YesString literal'Integer'

Valid data type strings:


The output value to write if the tested value is mismatched for the specified data type.

Required?Data TypeExample Value
YesString or numeric literal'Data type mismatch'

Example - IF* functions for data type validation