SSIS Derived Column System Variable Length

Question

I am trying to recover a part of a flat file name (collection) into a derived column. When I create my derived column I drag and drop the User:FilesToImport variable and the data type is automatically set to DT_WSTR and length to 24, not editable. As the variable contains a path that is longer than 24 chars I cannot use the SUBSTR functions that is supposed to start at the 26th Char to recover the needed data. Why is the length limited to 24 char? How to proceed? Thx

Answer 1

The Derived Column Editor is going to guess at the length based on the current value of the variable @[User::FilesToImport].

You can provide an explicit length to the column by casting it to the appropriate length (DT_WSTR, 90) @[User::FilesToImport] after applying whatever modifications you require.