Except vs NotNull in Sql Server

EXCEPT & INTERSECT command in SQL Server

EXCEPT

In this Article EXCEPT command use to commind two queries and find dinctinct records. EXCEPT returns any left query values which are not exist in right query. You can use Except command and easily find distinct value of one table when you want filter values.

SYNTAX

The Syntax of EXCEPT command

SELECT ColumnName1,ColumnName2,....ColumnNameN FROM TableName1
EXCEPT
SELECT ColumnName1,ColumnName2,....ColumnNameN FROM TableName2

Note - You Should know about same number of column in all Queries Example of Except Command in SQL server you can more clear in example

Example

. SELECT * from Table1
EXCEPT
select * from Table2

Note -You can write this query and execute (f5) after that You got result 'name which is ditinct and not match in right table.'
Result - You can see output record.
Image

Intersect

In this Article Intersect command use to commind two queries and find common records. You can use Intersect command and easily find common values.

SYNTAX

The Syntax of Intersect command

SELECT ColumnName1,ColumnName2,....ColumnNameN FROM TableName1
Intersect
SELECT ColumnName1,ColumnName2,....ColumnNameN FROM TableName2

Note - You Should know about same number of column in all Queries Example of Intersect Command in SQL server you can more clear in example

Example

SELECT * from Table1
INTERSECT
select * from Table2

Note -You can write this query and execute (f5) after that You find result 'name which is common in both table.'
Result - You can see output record.
Image

What is a NULL Value in Sql?

In this tutorial we describe that NULL value is a field with does not have any value. You can Insrt a new record and update without any value then field have 'no value' and field will be saved with a NULL value
Note - NULL value is different from a zero value or a field that contains spaces. A field with a NULL value is one that has been left blank during record creation.

What is Not NULL Value in Sql?

In this tutorial we describe that Not NULL value is a field which have value ,doesn't null value.

Difference between Except vs Not In

Except

EXCEPT filters the DISTINCT values from the left-hand table that do not appear in the right-hand table. It's essentially the same as doing a NOT EXISTS with a DISTINCT clause.
It also expects the two tables (or subset of columns from the tables) to have the same number of columns in the left and right hand side of the query

NOT IN

NOT IN does not filter for DISTINCT values and returns all values from the left-hand table that do not appear in the right-hand table.
NOT IN requires you compare a single column from one table with a single column from another table or subquery.
For example, if your subquery was to return multiple columns:

SELECT * FROM TableA AS nc WHERE ID NOT IN (SELECT ID, Name FROM TableB AS ec)