According to the ANSI standards SQL:92, SQL:1999, and SQL:2003, a UNIQUE constraint should disallow duplicate non-NULL values, but allow multiple NULL values. SQL ...

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 ...

SQL Interview questions related to NULL. Here are ten common SQL interview questions related to NULL values, along with their answers, you can also check the video about the same in first comment. 1.