NULL (SSIS Expression)
Applies to: 
SQL Server
SSIS Integration Runtime in Azure Data Factory
Returns a null value of a requested data type.
Syntax
NULL(typespec)
Arguments
typespec
Is a valid data type. For more information, see Integration Services Data Types.
Result Types
Any valid data type with a null value.
Remarks
NULL returns a null result if the argument is null.
Parameters are required to request a null value for some data types. The following table lists these data types and their parameters.
| Data type | Parameter | Example |
|---|---|---|
| DT_STR | charcount codepage |
(DT_STR,30,1252) casts 30 characters to the DT_STR data type using the 1252 code page. |
| DT_WSTR | charcount | (DT_WSTR,20) casts 20 characters to the DT_WSTR data type. |
| DT_BYTES | bytecount | (DT_BYTES,50) casts 50 bytes to the DT_BYTES data type. |
| DT_DECIMAL | scale | (DT_DECIMAL,2) casts a numeric value to the DT_DECIMAL data type using a scale of 2. |
| DT_NUMERIC | precision scale |
(DT_NUMERIC,10,3) casts a numeric value to the DT_NUMERIC data type using a precision of 10 and a scale of 3. |
| DT_TEXT | codepage | (DT_TEXT,1252) casts a value to the DT_TEXT data type using the 1252 code page. |
Expression Examples
These examples return the null value of the data types: DT_STR, DT_DATE, and DT_BOOL.
NULL(DT_STR,10,1252)
NULL(DT_DATE)
NULL(DT_BOOL)