In Extract Transform & Load (ETL) operation, we come across scenario's where the target column where we are pushing data is mandatory (not null) column. But often due to bad data in source \ lack of ...

Introduction What is SQL NULL ? Table used in this article Functions to handle SQL NULL Value IsNull() Coalesce() Aggregating Data with NULL Value Handling NULL values in the report Examples on SQL ...

-- What it does: Shows why NULL cannot be compared using = or != -- Why use it: Prevents common beginner mistake ...