A derived column transformation evaluates SSIS expressions for each input row, creating new output columns or replacing existing ones before data reaches its destination. section 6.3.2
Configure the transformation by:
- Selecting a replacement column or entering a new derived-column name. section 6.3.2
- Building expressions from columns, variables, parameters, functions, operators, and literals. section 6.3.2
- Checking automatically inferred data type, length, precision, scale, and code page; red expressions indicate parse errors. section 6.3.2
Marketing impressions data flow
A staging source uses derived columns to convert GUIDs by adding curly braces and casting to DT_GUID, normalize EventTime before casting to DB_TIMESTAMP, convert ReferralURL to DT_TEXT, and turn the string "NULL" StateID into a database null. section 6.3.2
Listing 6.6 SSIS expressions
(DT_GUID)("{" + (DT_WSTR,36)(ImpressionUID) + "}") #1
(DT_GUID)("{" + (DT_WSTR,36)(CookieID) + "}") #2
(DT_DBTIMESTAMP)(REPLACE((DT_WSTR,26)EventTime,"/","-")) #3
(DT_TEXT,1252)ReferralURL #4
(DT_UI1)((DT_WSTR,50)StateID == "NULL" ? NULL(DT_WSTR,50) : #5
(DT_WSTR,50)StateID) #5
Use the SSIS expression listing to inspect the concrete casts, replacement of slash characters, text conversion, and conditional null handling. section 6.3.2
