Sql Except | Minus Operator

The SQL EXCEPT operator is used to compare and get only unique results from two result sets.

It is used to combine two SELECT statements and returns records from the first SELECT statement that are not available by the second SELECT statement.

The two queries must result in the same number of columns and compatible data types in order to combine.

• The number and the order of the columns must be the same in both queries.
• The data types must be the same and compatible.

The SQL EXCEPT clause/operator joins two SELECT statements and returns rows from the first SELECT statement that the second SELECT query does not return.

This indicates that EXCEPT only returns rows that aren't found in the second SELECT statement.

The EXCEPT operator follows the same rules as the UNION operator. The EXCEPT operator is not supported by MySQL.

When two SELECT queries are being used to select records, the SQL EXCEPT statement is one of the most widely used to filter records.

The negative operator in mathematics is remarkably similar to how a SQL EXCEPT statement works.

The SQL EXCEPT operator is one of SQL Server's set operators. This SQL Server is being used to return different rows from the left-hand side query that the right-hand side query did not output.

Syntax:

SELECT Column_Name1, Column_Name2 ......., Column_NameN FROM Table1
EXCEPT
SELECT Column_Name1, Column_Name2 ......., Column_NameN FROM Table2

Example 1: A SQL EXCEPT statement can filter records from a single table in adding to filtering records from two tables. The following EXCEPT statement, for instance, will output all records from the Books1 database when the price is less than or equal to 5000:

USE BookStore
SELECT id, name, category, price FROM Books1
Except
SELECT id, name, category, price FROM Books1 WHERE price > 5000

Two SELECT commands operate on a single table, Books1, in the script provided.

The EXCEPT statement's right-hand SELECT query retrieves all records with a price greater than 5000. All of the entries from the Books1 table are returned by the SELECT statement on the left side of the EXCEPT statement.

Following that, the EXCEPT statement separates the records chosen by the SELECT statement on the right from those supplied by the SELECT query on the left. As a result, we're left with only the records from the Books table whose price is less than 5000.

Example 2: Assume we have two relationships: students and teaching assistants (Teaching Assistant). All students who are not teaching assistants will be returned. The question can be phrased as follows:

Students Table:

TA Table:

SELECT Name
FROM Students
EXCEPT
SELECT NAME
FROM TA;

Output:

Example 3: The following query will return total records from Employ that are not present in Employees2016 table and display the result:

SELECT [ID]
 ,[FirstName]
 ,[LastName]
 ,[Occupation]
 ,[YearlyIncome]
 ,[Sales]
  FROM [Employ]
EXCEPT
SELECT [ID]
 ,[FirstName]
 ,[LastName]
 ,[Occupation]
 ,[YearlyIncome]
 ,[Sales]
FROM [Employees 2016]

Example 4: Here, the given condition could be any given expression based on your requirement.

SELECT  ID, NAME, AMOUNT, DATE
 FROM CUSTOMERS
 LEFT JOIN ORDERS
 ON CUSTOMERS.ID = ORDERS.CUSTOMER_ID
EXCEPT
 SELECT  ID, NAME, AMOUNT, DATE
 FROM CUSTOMERS
 RIGHT JOIN ORDERS
 ON CUSTOMERS.ID = ORDERS.CUSTOMER_ID;

Output:

Duplicates are not eliminated by the EXCEPT ALL operator. EXCEPT ALL returns all records from the first table that are absent from the second table, leaving duplicates. Apparently, this operation is not supported by SQL Server. The EXCEPT operator does not distinguish between NULLs when it comes to row elimination and duplication deletion.

Syntax:

Except for rows that are also in the second result, the table operator except all returns the rows from the first result.

SELECT …
  FROM …
EXCEPT ALL
SELECT …
  FROM …

Both sides of unless, like all table operators, must have the same number of columns and their types must be suitable based on their location.

For this operation, all null values are treated as one (and not as distinct).

Example: A version of the Except operation is the Except all operation. The duplicate tuples are retained as a result of the Except all action. To find a list of courses that were offered in Spring 2019 but not in Fall 2018, run the following query:

(select Course-id
from Section
where Semester =‘Spring’ and year=2019)
Except
(select Course-id
from Section
where Semester=‘Fall’ and year=2018);

So that was all about SQL Set operations. Understand that set operations only apply to type compatible relations with the same domain and an equal number of attributes.

An EXCEPT statement can be used to filter records from a single table in addition to filtering records from two tables.

Example 1: The EXCEPT statement below returns all records from the Books1 database with a price of less than or equal to 5000:

USE BookStore
SELECT id, name, category, price FROM Books1
Except
SELECT id, name, category, price FROM Books1 WHERE price > 5000;

In the script above, we have two SELECT statements operating on a single table i.e. Books1.

On the right-hand side of the EXCEPT statement, the SELECT statement picks all records with a price greater than 5000. All of the records from the Books1 table are returned by the SELECT statement on the left side of the EXCEPT statement.

Following that, the EXCEPT statement separates the records chosen by the SELECT statement on the right from those obtained by the SELECT query on the left. As a result, we're left with only the records from the Books table whose price is less than 5000.

Example 2: We use the EXCEPT keyword to exclude records with salaries of less than $20,000 from the result set of the query that retrieves name, position, and technology from the developer's database, and we can use the accompanying query expression :

SELECT NAME,
POSITION,
technology
FROM
`developers`
EXCEPT
SELECT
NAME,
POSITION,
technology
FROM
`developers`
WHERE salary < 20000;

Example 3: The EXCEPT statement below will return all records from the customer table that are older than 21:

SELECT id, name, age, salary FROM customer  
EXCEPT  
SELECT id, name, age, salary FROM customer WHERE age > 21;

The first SELECT query in this script retrieves all records from the customer table, whereas the second query retrieves just those records with an age greater than 21. Following that, the EXCEPT statement uses both SELECT statements to filter the entries and only provides rows with an age greater than 21.

EXCEPT and EXCEPT ALL yield rows that match one relation but not the other. It's worth noting that MINUS is an acronym for EXCEPT.

EXCEPT

The EXCEPT set operator returns all unique rows picked by the first query, but not those picked by the second.

The MINUS operator and the ANSI set operator EXCEPT DISTINCT are functionally similar.

EXCEPT (or EXCEPT DISTINCT) only accepts distinct rows.

EXCEPT ALL

The EXCEPT ALL set operator returns all rows picked by the first query but not those selected by the second.

xThis is the same as the MINUS ALL operator in terms of functionality.

Duplicates in the result rows are not eliminated by EXCEPT ALL.

Syntax:

[ ( ] relation [ ) ] EXCEPT | MINUS [ ALL | DISTINCT ] [ ( ] relation [ ) ]

The Syntax for except and exceptall

(SELECT * FROM T1)
EXCEPT ALL
(SELECT * FROM T2)

Example 1: Departments 10, 20, and 30 would be returned by the first query in the instance below, but they are eliminated since this second query returns them. Only one row remains for department 10:

Except Example

select department_id, department_name
from   departments
where  department_id <= 30
except
select department_id, department_name
from   departments
where  department_id >= 20
order by 1;

Output:

Except All Example

We must first build some duplicate rows. To replicate the rows in the department's table, we use a WITH clause with a UNION ALL in the following query. The duplicate data is then queried.

with d1 as (
  select department_id, department_name
  from   departments
  union all
  select department_id, department_name
  from   departments
)
select department_id, department_name
from   d1
where  department_id <= 30
order by 1;

Output:

Example 2:

SELECT c FROM number1 EXCEPT SELECT c FROM number2;

Output:

SELECT c FROM number1 EXCEPT ALL (SELECT c FROM number2);

Output:

Main Article :- Sql difference between EXCEPT and INTERSECT

INTERSECT and EXCEPT can be used in distributed queries, but they are only processed on the local server and are not forwarded to the linked server.

EXCEPT and INTERSECT return column names from the result set that match the column names returned by the query on the operator's left side.

When comparing more than two sets of queries, use EXCEPT or INTERSECT. When you do, you decide on data type conversion by analyzing two queries at a time and applying the previously specified expression analysis rules.

When using an EXCEPT or INTERSECT operation, you can employ fast forward-only and static cursors in the result set. You can also utilize an EXCEPT or INTERSECT operation with a keyset-driven or dynamic cursor. When you do this, the pointer in the operation output set is changed to a static cursor.

Except

EXCEPT returns a unique data value from the left query (query on the operand's left side) that does not present in the correct query (query on the right side of the operand).

The EXCEPT operator returns the distinction in the results after two query phrases are executed.

Intersect

INTERSECT receives the same data value for BOTH queries (queries on the left and right side of the operand).

Except for the rows that are also returned from the second set of rows, the result set will contain rows from the first set.

Syntax:

{ < query_specification> | ( < query_expression> ) }   
{ EXCEPT | INTERSECT }  
{ < query_specification> | ( < query_expression> ) }  

Example 1:

SELECT COL1 FROM Tbl_1 EXCEPT SELECT COL1 FROM tbl_2
GO

Example 2:

SELECT CustomerKey   
FROM FactInternetSales    
INTERSECT  | EXCEPT
SELECT CustomerKey   
FROM DimCustomer   
WHERE DimCustomer.Gender = 'F'  
ORDER BY CustomerKey;

Except it's not designed to work as a join. It's the same as putting your first query into a temp database and then removing any rows that correspond to the second query. This could be easily accomplished with a correctly constructed join or sub-select.

EXCEPT is more expensive than LEFT JOIN because it uses more SORT and TOP items.

In comparison, unless LEFT JOIN is a superior choice.

The JOIN clause is used to integrate the results from many tables. We occasionally require a result set that includes records from one table but none from the other. This offering benefits an EXCEPT clause/operator in this instance.

Except

With the EXCEPTION that both queries must have the same columns and that all columns will be matched.

The SQL EXCEPT clause is commonly used to filter records from many tables. This statement combines the two SELECT statements and returns records from the first SELECT query that aren't included in the results of the second SELECT query. To put it another way, it retrieves all rows from the first SELECT query while deleting duplicate rows from the second.

To put it another way, it retrieves all distinct records from the first dataset while excluding entries from the second dataset.

EXCEPT Syntax:

SELECT t.ID, t.Name FROM #temp1 t
EXCEPT
SELECT t.ID, t.Name  FROM #temp2 t

Example: Let’s look at examples of the two methods to illustrate:

[cc lang=”sql”]
— using EXISTS to check for existence
SELECT P.ProductID
FROM Production.Product p
WHERE EXISTS
(
SELECT 1
FROM Sales.SalesOrderDetail sod
WHERE sod.ProductID = p.ProductID
)

Left Join

The LEFT JOIN command returns all records from the first left table, the matched records from the second right table, and NULL values from the right side for records from the left table that have no match in the right table. If no suitable join values are found, NULL is returned.

Syntax:

SELECT t.ID, t.Name  FROM #temp1 t
LEFT JOIN #temp2 t1 ON t.ID = t1.ID
WHERE t1.ID IS NULL

Example: Using LEFT JOIN to check for existence:

SELECT DISTINCT P.ProductID
FROM Production.Product p
LEFT JOIN Sales.SalesOrderDetail sod
ON sod.ProductID = p.ProductID
WHERE sod.SalesOrderDetailID IS NOT NULL

Main Article :- Sql difference between EXCEPT and NOT IN

The Except clause eliminates duplicates from the resultant set, whereas the NOT IN clause does not. It's also worth noting that MySQL doesn't accept EXCEPT.

NOT IN works in the same way as the EXCEPT operator. There are two significant distinctions between the EXCEPT and NOT IN operators:

EXCEPT

The EXCEPT operator filters out duplicate entries and returns only DISTINCT data.

The EXCEPT operator retrieves all distinctive rows from the left-hand table that do not appear in the right-hand table. When there are no matching rows in the correct query, use the EXCEPT operator. With DISTINCT queries, EXCEPT is comparable to NOT IN. The Left Anti-Semi-Join is equal to the EXCEPT operator.

When two SELECT queries are being used to choose records, the SQL EXCEPT statement is one of the most widely used statements to filter records.

Syntax for Except:

SELECT column_lists from table_name1  
EXCEPT  
SELECT column_lists from table_name2;

NOT IN

"NOT IN" returns all rows from the left hand side table that aren't in the right hand side table, but it doesn't eliminate duplicate rows.

The NOT IN operator in SQL Server is used to substitute a group of parameters that have been joined with an AND using the <> (or!=) operator. It can make SELECT, UPDATE, and DELETE SQL commands more understandable.

Syntax for NOT IN

NOT condition

Example 1: Let us use a simple example to demonstrate this. You may test the following two queries with various operators to observe how they function identically.

-- EXCEPT

USE AdventureWorks2014;
GO
SELECT ProductID
FROM Production.Product
EXCEPT
SELECT ProductID
FROM Production.WorkOrder; 
GO

-- NOT IN

USE AdventureWorks2014;
GO
SELECT ProductID
FROM Production.Product
WHERE ProductID
NOT IN (
SELECT ProductID
FROM Production.WorkOrder);
GO

Example 2: Example of EXCEPT vs NOT IN in SQL SERVER:

create table #tblsample (ProductId tinyint)
create table #tblsample2 (ProductId tinyint)

--insert values to tbl 1
insert into #tblsample values (1)
insert into #tblsample values (2)
insert into #tblsample values (3)
insert into #tblsample values (4)

--insert values to tbl 2
insert into #tblsample2 values (1)

--SELECT
select * from #tblsample
select * from #tblsample2

--USE EXCEPT
select * from #tblsample
except
select * from #tblsample2

--USE NOT IN
select * from #tblsample
where productid NOT IN(
select * from #tblsample2)

Example 3:

--Except returns 

SELECT nc.ID FROM# NewData AS nc  
EXCEPT  
SELECT ec.ID FROM# ExistingData AS ec  
  
--NOT IN returns all values without filtering  

SELECT nc.ID FROM# NewData AS nc  
WHERE ID NOT IN(SELECT ec.ID FROM# ExistingData AS ec)

Example:

SELECT 'COUNT=' + CONVERT(VARCHAR(64), COUNT(company)) AS sites 
FROM (

    SELECT s.company
    FROM   site s 
    WHERE  s.sitetype = 'om' 
           AND s.status = 1 
    EXCEPT 
    SELECT DISTINCT sg.company 
    FROM   snmpmibdevice AS sdevice 
           JOIN site sg 
             ON sg.guid = sdevice.siteguid 
           JOIN snmpmibdata sdata 
             ON sdata.snmpmibdeviceguid = sdevice.snmpmibdeviceguid 
    WHERE  sdata.sampletimestamp > Dateadd (mi, -15, Getutcdate()) 
           AND sg.sitetype = 'OM' 
) a

Example 1:

With cte as
 (select *, row_number() 
 over(partition by [Employee ID] order by [QTR] DESC,Wk DESC) rownumber 
 from tbl_HC
 ), cte1 as 
 (
select *, row_number() 
 over(partition by [Employee ID] order by [QTR] DESC,Wk DESC) rownumber 
 from tbl_HC)
select * from cte 
 where rownumber =1
 and QTR= (Select max(QTR) from tbl_SDS_Headcount_Manageby)
except
 select * from cte1
 where rownumber =1
 and Wk= (
 Select max(Wk) from tbl_HC
 where QTR = (Select max(QTR) from tbl_HC))

Example 2:

WITH mytable (id) AS
(
SELECT  1
UNION ALL
SELECT  2
UNION ALL
SELECT  3
),
q AS
(
SELECT  id
FROM    mytable
UNION ALL
SELECT  *
FROM    (
SELECT  id
FROM    othertable
EXCEPT
SELECT  *
FROM    q
) q2
)
SELECT  TOP 20 *
FROM    q

If the EXCEPT operator were applied to the whole result set generated by the preceding query in recursive2, it would give a single row 3. However, it only returns 1 and 3, indicating that the EXCEPT clause was only performed to the last row once more.

A correctly constructed set-based recursive CTE should not behave like this. However, this is precisely how the CONNECT BY query works. It divides the record set into individual records and implements the recursive part to each one.

Example 3: To clarify the difference between anchor values and recursive items (it does not change the semantic).

DECLARE @V TABLE (a INTEGER NOT NULL)
INSERT  @V (a) VALUES (1),(2)
;
WITH rCTE AS 
(
-- Anchor

SELECT
v.a
FROM @V AS v

UNION ALL

-- Recursive
SELECT
   x.a
FROM
 (
SELECT
 v2.a
 FROM @V AS v2
    
 EXCEPT
    
SELECT
 r.a
 FROM rCTE AS r
 ) AS x
)
 SELECT
 r2.a
 FROM rCTE AS r2
 OPTION (MAXRECURSION 0)

The exception actually used to same column, let's see how it's working on different columns.

The basic syntax of EXCEPT is as follows.

SELECT column1 [, column2 ]
FROM table1 [, table2 ]
[WHERE condition]

EXCEPT (column1, column 2)

SELECT column1 [, column2 ]
FROM table1 [, table2 ]
[WHERE condition]

Example: Exclude multiple columns in EXCEPT clause:

SELECT * 
EXCEPT (IsCurrent, StartDate, EndDate)
FROM
  `test`.dim_customer

Example: This is a relational algebraic definition of maximum: Remove all non-maximum values from table R, leaving only the maximal values:

(SELECT DISTINCT * FROM R)
 EXCEPT
(SELECT R.a
 FROM R, R AS S
 WHERE R.a < S.a)

The query returns nothing if R is empty.

The query returns NULL in addition to whatever maximum integer is present if R has a NULL value (if any). Because NULL is never included in the lower subquery, NULL is never deducted from R.

Because it's a little strange having a MAX expression return two rows with different values, the following expression modifies the EXCEPT expression to exclude NULL from the result:

The ORDER BY clause in the last query is used to sort the result set generated by the EXCEPT operator.

Example 1: SQL Except with Order By:

Select "State" ,"Country" from "Customer"
Except
Select "State","Country" from "Supplier" order by "State"

Output:

Example 2: For instance, the illustration joins both tables and sorts the result set in ascending order by their names:

SELECT  id, name, 
 amount, date
 FROM customer
 LEFT JOIN orders
 ON customer.id = orders.order_id
EXCEPT
 SELECT  id, name, amount, date
 FROM customer
 RIGHT JOIN orders
 ON customer.id = orders. order_id
 ORDER BY name;

Example 3: sql except with orderby:

SELECT suppl_id, suppl_name
FROM suppls
WHERE suppl_id < 30
EXCEPT
SELECT com_id, com_name
FROM coms
WHERE state_1 = 'Florida'
ORDER BY 2;

Because the column names of the two SELECT operators vary in this EXCEPT instance, it is preferable to refer to the columns in the ORDER BY clause by their location in the result set. In this case, we use ORDER BY 2 to sort the results by suppl_name / com_name in ascending order.

In their target lists, any queries that use the UNION, INTERSECT, or EXCEPT operators should have an identical number of expressions.

The UNION ALL operator is similar to the UNION operator in that it combines several result sets into a single result set. However, unlike the UNION operator, duplicate rows are not deleted from the result set when using UNION ALL.

Syntax:

SELECT * FROM Table1
UNION ALL
SELECT * FROM Table2
UNION ALL
SELECT * FROM Table3

Example 1: You can delete the additional column from the query in this approach. Any query can include this extra column. In query 1, we have an extra field called [Updated Date]. So let's get rid of it.

USE tempdb
GO
SELECT [ID],[Name]
FROM tbl_sample_1
UNION ALL
SELECT [ID],[Name]
FROM tbl_sample_2

Excluding SQL, The where clause should only be used once after the final choice statement.

Syntax:

( SELECT KEY_FIELD_1,LOOKUP_FIELD_1  
FROM TABLE_1  
WHERE FILTER_FIELD = '1' )  
EXCEPT  
( SELECT KEY FIELD_2,LOOKUP_FIELD_2  
FROM TABLE_2 )

Example 1: sql except with where clause

Select Id, Name, Gender, Salary
From Employees
Where Salary >= 50000
Except
Select Id, Name, Gender, Salary
From Employees
Where Salary >= 60000
order By Name

Example 2: The following SQL code can be used to retrieve entries from the Name column that aren't present in both recordsets with the stated condition:

SELECT Name FROM Product
EXCEPT
SELECT Name FROM Inventory
WHERE Quantity < 30
ORDER BY Name;

Output:

EXISTS simply determines whether the records returned by the query are valid. If you simply want to update specific entries, you'll need to use the IN operator in the where clause.

The EXISTS condition essentially means "update all rows if the subquery returns at least one entry," because the subquery is unrelated to any outer table.

Syntax:

I chose many rows of records from my EXCEPT select and updated them.

UPDATE t1
SET t1.col1 = t2.col1, t1.col2 = t2.col2, t1.col3 = t2.col3, t1.col4 = t2.col4, ........
FROM t2
WHERE t2.ID = t1.ID

AND

EXISTS
(SELECT col1, col2, col3, col4, ...........
FROM t1

EXCEPT

SELECT col1, col2, col3, col4, ...........
FROM t2)

Regrettably, it refreshes all records. Only those records that were obtained by the EXCEPT query should be updated.

update table
set column name =….
except (sub query giving other COLUMN VALUES as output)