SQL EXISTS Operator
EXISTS Operator
The EXISTS checks the existence of a result of a Subquery. The EXISTS subquery tests whether a subquery fetches at least one row. When no data is returned then this operator returns 'FALSE'.
A valid EXISTS subquery must contain an outer reference and it must be a correlated Subquery.
The select list in the EXISTS subquery is not actually used in evaluating the EXISTS so it can contain any valid select list.
Syntax:
SELECT [column_name... | expression1 ] FROM [table_name] WHERE [NOT] EXISTS (subquery)
Parameters:
| Name | Description |
|---|---|
| column_name | Name of the column of the table. |
| expression1 | Expression made up of a single constant, variable, scalar function, or column name and can also be the pieces of a SQL query that compare values against other values or perform arithmetic calculations. |
| table_name | Name of the table. |
| WHERE [NOT] EXISTS | Tests the subquery for the existence of one or more rows. If a single row satisfies the subquery clause, it returns Boolean TRUE. When the subquery returns no matching rows the optional NOT keyword returns a Boolean TRUE. |
Contents:
Visual Presentation: SQL EXISTS Operator
DBMS Support: EXISTS Operator
| DBMS | Command |
| MySQL | Supported |
| PostgreSQL | Supported |
| SQL Server | Supported |
| Oracle | Supported |
Example: SQL EXISTS Operator
To get 'agent_code','agent_name','working_area' and 'commission' from the 'agents', with following conditions-
1. 'grade' in 'customer' table must be 3,
2. 'agent_code' in 'customer' and 'agents' table must match,
3. 'commission' of 'agents' should arrange in ascending order,
4. the above condition (1) and (2) should match at least one row,
the following sql statement can be used :
SELECT agent_code,agent_name,working_area,commission
FROM agents
WHERE exists
(SELECT * FROM customer
WHERE grade=3
AND agents.agent_code=customer.agent_code)
ORDER BY commission;
Sample table: customer
+-----------+-------------+-------------+--------------+--------------+-------+-------------+-------------+-------------+---------------+--------------+------------+ |CUST_CODE | CUST_NAME | CUST_CITY | WORKING_AREA | CUST_COUNTRY | GRADE | OPENING_AMT | RECEIVE_AMT | PAYMENT_AMT |OUTSTANDING_AMT| PHONE_NO | AGENT_CODE | +-----------+-------------+-------------+--------------+--------------+-------+-------------+-------------+-------------+---------------+--------------+------------+ | C00013 | Holmes | London | London | UK | 2 | 6000.00 | 5000.00 | 7000.00 | 4000.00 | BBBBBBB | A003 | | C00001 | Micheal | New York | New York | USA | 2 | 3000.00 | 5000.00 | 2000.00 | 6000.00 | CCCCCCC | A008 | | C00020 | Albert | New York | New York | USA | 3 | 5000.00 | 7000.00 | 6000.00 | 6000.00 | BBBBSBB | A008 | | C00025 | Ravindran | Bangalore | Bangalore | India | 2 | 5000.00 | 7000.00 | 4000.00 | 8000.00 | AVAVAVA | A011 | | C00024 | Cook | London | London | UK | 2 | 4000.00 | 9000.00 | 7000.00 | 6000.00 | FSDDSDF | A006 | | C00015 | Stuart | London | London | UK | 1 | 6000.00 | 8000.00 | 3000.00 | 11000.00 | GFSGERS | A003 | | C00002 | Bolt | New York | New York | USA | 3 | 5000.00 | 7000.00 | 9000.00 | 3000.00 | DDNRDRH | A008 | | C00018 | Fleming | Brisban | Brisban | Australia | 2 | 7000.00 | 7000.00 | 9000.00 | 5000.00 | NHBGVFC | A005 | | C00021 | Jacks | Brisban | Brisban | Australia | 1 | 7000.00 | 7000.00 | 7000.00 | 7000.00 | WERTGDF | A005 | ............. | C00011 | Sundariya | Chennai | Chennai | India | 3 | 7000.00 | 11000.00 | 7000.00 | 11000.00 | PPHGRTS | A010 | +-----------+-------------+-------------+--------------+--------------+-------+-------------+-------------+-------------+---------------+--------------+------------+Sample table : agents
+------------+----------------------+--------------------+------------+-----------------+---------+ | AGENT_CODE | AGENT_NAME | WORKING_AREA | COMMISSION | PHONE_NO | COUNTRY | +------------+----------------------+--------------------+------------+-----------------+---------+ | A007 | Ramasundar | Bangalore | 0.15 | 077-25814763 | | | A003 | Alex | London | 0.13 | 075-12458969 | | | A008 | Alford | New York | 0.12 | 044-25874365 | | | A011 | Ravi Kumar | Bangalore | 0.15 | 077-45625874 | | | A010 | Santakumar | Chennai | 0.14 | 007-22388644 | | | A012 | Lucida | San Jose | 0.12 | 044-52981425 | | | A005 | Anderson | Brisban | 0.13 | 045-21447739 | | | A001 | Subbarao | Bangalore | 0.14 | 077-12346674 | | | A002 | Mukesh | Mumbai | 0.11 | 029-12358964 | | ........... | A009 | Benjamin | Hampshair | 0.11 | 008-22536178 | | +------------+----------------------+--------------------+------------+-----------------+---------+
Output :
AGENT_CODE AGENT_NAME WORKING_AREA COMMISSION ---------- -------------------- -------------------- ---------- A009 Benjamin Hampshair .11 A002 Mukesh Mumbai .11 A008 Alford New York .12 A010 Santakumar Chennai .14
SELECT using EXISTS
Sample table : employeesemployee_id first_name last_name email phone_number hire_date job_id salary commission_pct manager_id department_id ----------- ---------- ---------- ---------- ------------ ---------- ---------- ---------- -------------- ---------- ------------- 100 Steven King SKING 515.123.4567 6/17/1987 AD_PRES 24000 90 101 Neena Kochhar NKOCHHAR 515.123.4568 6/18/1987 AD_VP 17000 100 90 102 Lex De Haan LDEHAAN 515.123.4569 6/19/1987 AD_VP 17000 100 90 103 Alexander Hunold AHUNOLD 590.423.4567 6/20/1987 IT_PROG 9000 102 60 104 Bruce Ernst BERNST 590.423.4568 6/21/1987 IT_PROG 6000 103 60 105 David Austin DAUSTIN 590.423.4569 6/22/1987 IT_PROG 4800 103 60 106 Valli Pataballa VPATABAL 590.423.4560 6/23/1987 IT_PROG 4800 103 60 107 Diana Lorentz DLORENTZ 590.423.5567 6/24/1987 IT_PROG 4200 103 60 108 Nancy Greenberg NGREENBE 515.124.4569 6/25/1987 FI_MGR 12000 101 100 ........... 206 William Gietz WGIETZ 515.123.8181 10/1/1987 AC_ACCOUNT 8300 205 110Sample table: departments
+---------------+----------------------+------------+-------------+ | DEPARTMENT_ID | DEPARTMENT_NAME | MANAGER_ID | LOCATION_ID | +---------------+----------------------+------------+-------------+ | 10 | Administration | 200 | 1700 | | 20 | Marketing | 201 | 1800 | | 30 | Purchasing | 114 | 1700 | | 40 | Human Resources | 203 | 2400 | | 50 | Shipping | 121 | 1500 | | 60 | IT | 103 | 1400 | | 70 | Public Relations | 204 | 2700 | | 80 | Sales | 145 | 2500 | | 90 | Executive | 100 | 1700 | | 100 | Finance | 108 | 1700 | .......... | 270 | Payroll | 0 | 1700 | +---------------+----------------------+------------+-------------+Sample table: locations
+-------------+------------------------------------------+-------------+---------------------+-------------------+------------+ | LOCATION_ID | STREET_ADDRESS | POSTAL_CODE | CITY | STATE_PROVINCE | COUNTRY_ID | +-------------+------------------------------------------+-------------+---------------------+-------------------+------------+ | 1000 | 1297 Via Cola di Rie | 989 | Roma | | IT | | 1100 | 93091 Calle della Testa | 10934 | Venice | | IT | | 1200 | 2017 Shinjuku-ku | 1689 | Tokyo | Tokyo Prefecture | JP | | 1300 | 9450 Kamiya-cho | 6823 | Hiroshima | | JP | | 1400 | 2014 Jabberwocky Rd | 26192 | Southlake | Texas | US | | 1500 | 2011 Interiors Blvd | 99236 | South San Francisco | California | US | | 1600 | 2007 Zagora St | 50090 | South Brunswick | New Jersey | US | | 1700 | 2004 Charade Rd | 98199 | Seattle | Washington | US | | 1800 | 147 Spadina Ave | M5V 2L7 | Toronto | Ontario | CA | ............ | 3200 | Mariano Escobedo 9991 | 11932 | Mexico City | Distrito Federal, | MX | +-------------+------------------------------------------+-------------+---------------------+-------------------+------------+
To display the employee details who are working in the country UK, we can use the following statement:
SELECT EMPLOYEE_ID, FIRST_NAME, SALARY, DEPARTMENT_ID
FROM EMPLOYEES E
WHERE EXISTS (SELECT 1
FROM DEPARTMENTS D, LOCATIONS L
WHERE D.LOCATION_ID = L.LOCATION_ID
AND D.DEPARTMENT_ID = E.DEPARTMENT_ID
AND L.COUNTRY_ID = 'UK');
Output :
EMPLOYEE_ID FIRST_NAME SALARY DEPARTMENT_ID
----------- -------------------- ---------- -------------
203 Susan 6500 40
179 Charles 6200 80
177 Jack 8400 80
176 Jonathon 8600 80
175 Alyssa 8800 80
174 Ellen 11000 80
173 Sundita 6100 80
172 Elizabeth 7300 80
171 William 7400 80
170 Tayler 9600 80
169 Harrison 10000 80
168 Lisa 11500 80
167 Amit 6200 80
166 Sundar 6400 80
. . .
SQL Exists with GROUP BY
Here we have discussed how SQL EXIST can work with GROUP BY in a select statement.
Example:
Sample table: customer+-----------+-------------+-------------+--------------+--------------+-------+-------------+-------------+-------------+---------------+--------------+------------+ |CUST_CODE | CUST_NAME | CUST_CITY | WORKING_AREA | CUST_COUNTRY | GRADE | OPENING_AMT | RECEIVE_AMT | PAYMENT_AMT |OUTSTANDING_AMT| PHONE_NO | AGENT_CODE | +-----------+-------------+-------------+--------------+--------------+-------+-------------+-------------+-------------+---------------+--------------+------------+ | C00013 | Holmes | London | London | UK | 2 | 6000.00 | 5000.00 | 7000.00 | 4000.00 | BBBBBBB | A003 | | C00001 | Micheal | New York | New York | USA | 2 | 3000.00 | 5000.00 | 2000.00 | 6000.00 | CCCCCCC | A008 | | C00020 | Albert | New York | New York | USA | 3 | 5000.00 | 7000.00 | 6000.00 | 6000.00 | BBBBSBB | A008 | | C00025 | Ravindran | Bangalore | Bangalore | India | 2 | 5000.00 | 7000.00 | 4000.00 | 8000.00 | AVAVAVA | A011 | | C00024 | Cook | London | London | UK | 2 | 4000.00 | 9000.00 | 7000.00 | 6000.00 | FSDDSDF | A006 | | C00015 | Stuart | London | London | UK | 1 | 6000.00 | 8000.00 | 3000.00 | 11000.00 | GFSGERS | A003 | | C00002 | Bolt | New York | New York | USA | 3 | 5000.00 | 7000.00 | 9000.00 | 3000.00 | DDNRDRH | A008 | | C00018 | Fleming | Brisban | Brisban | Australia | 2 | 7000.00 | 7000.00 | 9000.00 | 5000.00 | NHBGVFC | A005 | | C00021 | Jacks | Brisban | Brisban | Australia | 1 | 7000.00 | 7000.00 | 7000.00 | 7000.00 | WERTGDF | A005 | ........... | C00011 | Sundariya | Chennai | Chennai | India | 3 | 7000.00 | 11000.00 | 7000.00 | 11000.00 | PPHGRTS | A010 | +-----------+-------------+-------------+--------------+--------------+-------+-------------+-------------+-------------+---------------+--------------+------------+
To get 'cust_code', 'cust_name', 'cust_city' and 'grade' from the 'customer' table, with following conditions -
1. 'grade' in 'customer' table must be 2,
2. more than 2 agents are present in grade 2,
3. 'grade' in customer table should make a group,
the following sql statement can be used :
SELECT cust_code,cust_name,cust_city,grade
FROM customer
WHERE grade=2 AND
EXISTS(
SELECT COUNT(*) FROM customer
WHERE grade=2
GROUP BY grade
HAVING COUNT(*)>2);
Output:
CUST_CODE CUST_NAME CUST_CITY GRADE ---------- ---------------------------------------- --------------- ---------- C00013 Holmes London 2 C00001 Micheal New York 2 C00025 Ravindran Bangalore 2 C00024 Cook London 2 C00018 Fleming Brisban 2 C00022 Avinash Mumbai 2 C00017 Srinivas Bangalore 2 C00003 Martin Torento 2 C00014 Rangarappa Bangalore 2 C00016 Venkatpati Bangalore 2
SQL Exists with IN
Here is an example of SQL EXISTS operator using IN operator.
HIn this page we are discussing the usage of SQL EXISTS with IN operator in a SELECT statement.
Example:
Sample table: customer+-----------+-------------+-------------+--------------+--------------+-------+-------------+-------------+-------------+---------------+--------------+------------+ |CUST_CODE | CUST_NAME | CUST_CITY | WORKING_AREA | CUST_COUNTRY | GRADE | OPENING_AMT | RECEIVE_AMT | PAYMENT_AMT |OUTSTANDING_AMT| PHONE_NO | AGENT_CODE | +-----------+-------------+-------------+--------------+--------------+-------+-------------+-------------+-------------+---------------+--------------+------------+ | C00013 | Holmes | London | London | UK | 2 | 6000.00 | 5000.00 | 7000.00 | 4000.00 | BBBBBBB | A003 | | C00001 | Micheal | New York | New York | USA | 2 | 3000.00 | 5000.00 | 2000.00 | 6000.00 | CCCCCCC | A008 | | C00020 | Albert | New York | New York | USA | 3 | 5000.00 | 7000.00 | 6000.00 | 6000.00 | BBBBSBB | A008 | | C00025 | Ravindran | Bangalore | Bangalore | India | 2 | 5000.00 | 7000.00 | 4000.00 | 8000.00 | AVAVAVA | A011 | | C00024 | Cook | London | London | UK | 2 | 4000.00 | 9000.00 | 7000.00 | 6000.00 | FSDDSDF | A006 | | C00015 | Stuart | London | London | UK | 1 | 6000.00 | 8000.00 | 3000.00 | 11000.00 | GFSGERS | A003 | | C00002 | Bolt | New York | New York | USA | 3 | 5000.00 | 7000.00 | 9000.00 | 3000.00 | DDNRDRH | A008 | | C00018 | Fleming | Brisban | Brisban | Australia | 2 | 7000.00 | 7000.00 | 9000.00 | 5000.00 | NHBGVFC | A005 | | C00021 | Jacks | Brisban | Brisban | Australia | 1 | 7000.00 | 7000.00 | 7000.00 | 7000.00 | WERTGDF | A005 | ............ | C00011 | Sundariya | Chennai | Chennai | India | 3 | 7000.00 | 11000.00 | 7000.00 | 11000.00 | PPHGRTS | A010 | +-----------+-------------+-------------+--------------+--------------+-------+-------------+-------------+-------------+---------------+--------------+------------+Sample table: orders
ORD_NUM ORD_AMOUNT ADVANCE_AMOUNT ORD_DATE CUST_CODE AGENT_CODE ORD_DESCRIPTION
---------- ---------- -------------- --------- --------------- --------------- -----------------
200114 3500 2000 15-AUG-08 C00002 A008
200122 2500 400 16-SEP-08 C00003 A004
200118 500 100 20-JUL-08 C00023 A006
200119 4000 700 16-SEP-08 C00007 A010
200121 1500 600 23-SEP-08 C00008 A004
200130 2500 400 30-JUL-08 C00025 A011
200134 4200 1800 25-SEP-08 C00004 A005
200108 4000 600 15-FEB-08 C00008 A004
200103 1500 700 15-MAY-08 C00021 A005
..........
200102 2000 300 25-MAY-08 C00012 A012
To get distinct 'agent_code' from the 'orders' table, with following conditions -
1. 'agent_code' must be within the resultant 'agent_code' from 'customer' table which satisfies the condition bellow :
2. 'payment_amt' of 'customer' table must be more than 3000,
3. number of rows having said 'payment_amount' is more than 10,
the following sql statement can be used :
SELECT DISTINCT(agent_code)
FROM orders
WHERE agent_code IN(
SELECT agent_code
FROM customer WHERE payment_amt>3000
AND EXISTS(SELECT COUNT(*)
FROM customer GROUP BY payment_amt
HAVING COUNT(*)>10));
Output:
AGENT_CODE ---------- A004 A002 A007 A009 A011 A012 A010 A001 A008 A006 A005 A003
INSERT using EXISTS
To add employee details to EMP_TEMP table who are working in the country UK, the following sql statement can be used :
INSERT INTO EMP_TEMP SELECT *
FROM EMPNEW E
WHERE EXISTS (SELECT 1
FROM DEPARTMENTS D, LOCATIONS L
WHERE D.LOCATION_ID = L.LOCATION_ID
AND D.DEPARTMENT_ID = E.DEPARTMENT_ID
AND L.COUNTRY_ID = 'UK');
Sample table : employees
employee_id first_name last_name email phone_number hire_date job_id salary commission_pct manager_id department_id ----------- ---------- ---------- ---------- ------------ ---------- ---------- ---------- -------------- ---------- ------------- 100 Steven King SKING 515.123.4567 6/17/1987 AD_PRES 24000 90 101 Neena Kochhar NKOCHHAR 515.123.4568 6/18/1987 AD_VP 17000 100 90 102 Lex De Haan LDEHAAN 515.123.4569 6/19/1987 AD_VP 17000 100 90 103 Alexander Hunold AHUNOLD 590.423.4567 6/20/1987 IT_PROG 9000 102 60 104 Bruce Ernst BERNST 590.423.4568 6/21/1987 IT_PROG 6000 103 60 105 David Austin DAUSTIN 590.423.4569 6/22/1987 IT_PROG 4800 103 60 106 Valli Pataballa VPATABAL 590.423.4560 6/23/1987 IT_PROG 4800 103 60 107 Diana Lorentz DLORENTZ 590.423.5567 6/24/1987 IT_PROG 4200 103 60 108 Nancy Greenberg NGREENBE 515.124.4569 6/25/1987 FI_MGR 12000 101 100 ............. 206 William Gietz WGIETZ 515.123.8181 10/1/1987 AC_ACCOUNT 8300 205 110Sample table: locations
+-------------+------------------------------------------+-------------+---------------------+-------------------+------------+ | LOCATION_ID | STREET_ADDRESS | POSTAL_CODE | CITY | STATE_PROVINCE | COUNTRY_ID | +-------------+------------------------------------------+-------------+---------------------+-------------------+------------+ | 1000 | 1297 Via Cola di Rie | 989 | Roma | | IT | | 1100 | 93091 Calle della Testa | 10934 | Venice | | IT | | 1200 | 2017 Shinjuku-ku | 1689 | Tokyo | Tokyo Prefecture | JP | | 1300 | 9450 Kamiya-cho | 6823 | Hiroshima | | JP | | 1400 | 2014 Jabberwocky Rd | 26192 | Southlake | Texas | US | | 1500 | 2011 Interiors Blvd | 99236 | South San Francisco | California | US | | 1600 | 2007 Zagora St | 50090 | South Brunswick | New Jersey | US | | 1700 | 2004 Charade Rd | 98199 | Seattle | Washington | US | | 1800 | 147 Spadina Ave | M5V 2L7 | Toronto | Ontario | CA | ............ | 3200 | Mariano Escobedo 9991 | 11932 | Mexico City | Distrito Federal, | MX | +-------------+------------------------------------------+-------------+---------------------+-------------------+------------+
Output:
Here is the rows inserted into the table EMP_TEMP are:
SQL> SELECT EMPLOYEE_ID, FIRST_NAME, HIRE_DATE, SALARY FROM emp_temp;
EMPLOYEE_ID FIRST_NAME HIRE_DATE SALARY
----------- -------------------- --------- ----------
145 John 01-OCT-04 14000
146 Karen 05-JAN-05 13500
147 Alberto 10-MAR-05 12000
148 Gerald 15-OCT-07 11000
149 Eleni 29-JAN-08 10500
150 Peter 30-JAN-05 10000
151 David 24-MAR-05 9500
152 Peter 20-AUG-05 9000
153 Christopher 30-MAR-06 8000
. . .
175 Alyssa 19-MAR-05 8800
176 Jonathon 24-MAR-06 8600
177 Jack 23-APR-06 8400
179 Charles 04-JAN-08 6200
203 Susan 07-JUN-02 6500
35 rows selected.
UPDATE using EXISTS
Sample table : employeesemployee_id first_name last_name email phone_number hire_date job_id salary commission_pct manager_id department_id ----------- ---------- ---------- ---------- ------------ ---------- ---------- ---------- -------------- ---------- ------------- 100 Steven King SKING 515.123.4567 6/17/1987 AD_PRES 24000 90 101 Neena Kochhar NKOCHHAR 515.123.4568 6/18/1987 AD_VP 17000 100 90 102 Lex De Haan LDEHAAN 515.123.4569 6/19/1987 AD_VP 17000 100 90 103 Alexander Hunold AHUNOLD 590.423.4567 6/20/1987 IT_PROG 9000 102 60 104 Bruce Ernst BERNST 590.423.4568 6/21/1987 IT_PROG 6000 103 60 105 David Austin DAUSTIN 590.423.4569 6/22/1987 IT_PROG 4800 103 60 106 Valli Pataballa VPATABAL 590.423.4560 6/23/1987 IT_PROG 4800 103 60 107 Diana Lorentz DLORENTZ 590.423.5567 6/24/1987 IT_PROG 4200 103 60 108 Nancy Greenberg NGREENBE 515.124.4569 6/25/1987 FI_MGR 12000 101 100 ............. 206 William Gietz WGIETZ 515.123.8181 10/1/1987 AC_ACCOUNT 8300 205 110
To update the commission of the employees to zero who earn the salary 14000 and above, the following sql statement can be used :
UPDATE EMPNEW E
SET COMMISSION_PCT = 0
WHERE EXISTS (SELECT 1
FROM EMPNEW
WHERE EMPLOYEE_ID = E.EMPLOYEE_ID
AND SALARY>=14000);
Output:
Here is the rows before update the commission :
EMPLOYEE_ID FIRST_NAME SALARY COMMISSION_PCT
----------- -------------------- ---------- --------------
100 Steven 24000
101 Neena 17000
102 Lex 17000
145 John 14000 .4
Here is the effected rows after update the commission :
EMPLOYEE_ID FIRST_NAME SALARY COMMISSION_PCT
----------- -------------------- ---------- --------------
100 Steven 24000 0
101 Neena 17000 0
102 Lex 17000 0
145 John 14000 0
DELETE using EXISTS
Sample table : employeesemployee_id first_name last_name email phone_number hire_date job_id salary commission_pct manager_id department_id ----------- ---------- ---------- ---------- ------------ ---------- ---------- ---------- -------------- ---------- ------------- 100 Steven King SKING 515.123.4567 6/17/1987 AD_PRES 24000 90 101 Neena Kochhar NKOCHHAR 515.123.4568 6/18/1987 AD_VP 17000 100 90 102 Lex De Haan LDEHAAN 515.123.4569 6/19/1987 AD_VP 17000 100 90 103 Alexander Hunold AHUNOLD 590.423.4567 6/20/1987 IT_PROG 9000 102 60 104 Bruce Ernst BERNST 590.423.4568 6/21/1987 IT_PROG 6000 103 60 105 David Austin DAUSTIN 590.423.4569 6/22/1987 IT_PROG 4800 103 60 106 Valli Pataballa VPATABAL 590.423.4560 6/23/1987 IT_PROG 4800 103 60 107 Diana Lorentz DLORENTZ 590.423.5567 6/24/1987 IT_PROG 4200 103 60 108 Nancy Greenberg NGREENBE 515.124.4569 6/25/1987 FI_MGR 12000 101 100 ........... 206 William Gietz WGIETZ 515.123.8181 10/1/1987 AC_ACCOUNT 8300 205 110
To delete the employee details from who worked 14 years and above, the following sql statement can be used :
DELETE FROM EMPNEW E
WHERE EXISTS (SELECT 1
FROM EMPNEW
WHERE EMPLOYEE_ID = E.EMPLOYEE_ID
AND (TO_CHAR(SYSDATE,'YYYY')- TO_CHAR(HIRE_DATE,'YYYY'))>=14);
Output:
Here is the rows before delete who worked for 14 years and more :
EMPLOYEE_ID FIRST_NAME HIRE_DATE
----------- -------------------- ---------
102 Lex 13-JAN-01
108 Nancy 17-AUG-02
109 Daniel 16-AUG-02
114 Den 07-DEC-02
203 Susan 07-JUN-02
204 Hermann 07-JUN-02
205 Shelley 07-JUN-02
206 William 07-JUN-02
Here is the output after execute the command :
SQL> DELETE FROM EMPNEW E 2 WHERE EXISTS (SELECT 1 3 FROM EMPNEW 4 WHERE EMPLOYEE_ID = E.EMPLOYEE_ID 5 AND (TO_CHAR(SYSDATE,'YYYY')- TO_CHAR(HIRE_DATE,'YYYY'))>=14); 8 rows deleted.
SQL NOT Exists
Here we have discussed how SQL NOT EXISTS works with a select statement.
Example:
Sample table: customer+-----------+-------------+-------------+--------------+--------------+-------+-------------+-------------+-------------+---------------+--------------+------------+ |CUST_CODE | CUST_NAME | CUST_CITY | WORKING_AREA | CUST_COUNTRY | GRADE | OPENING_AMT | RECEIVE_AMT | PAYMENT_AMT |OUTSTANDING_AMT| PHONE_NO | AGENT_CODE | +-----------+-------------+-------------+--------------+--------------+-------+-------------+-------------+-------------+---------------+--------------+------------+ | C00013 | Holmes | London | London | UK | 2 | 6000.00 | 5000.00 | 7000.00 | 4000.00 | BBBBBBB | A003 | | C00001 | Micheal | New York | New York | USA | 2 | 3000.00 | 5000.00 | 2000.00 | 6000.00 | CCCCCCC | A008 | | C00020 | Albert | New York | New York | USA | 3 | 5000.00 | 7000.00 | 6000.00 | 6000.00 | BBBBSBB | A008 | | C00025 | Ravindran | Bangalore | Bangalore | India | 2 | 5000.00 | 7000.00 | 4000.00 | 8000.00 | AVAVAVA | A011 | | C00024 | Cook | London | London | UK | 2 | 4000.00 | 9000.00 | 7000.00 | 6000.00 | FSDDSDF | A006 | | C00015 | Stuart | London | London | UK | 1 | 6000.00 | 8000.00 | 3000.00 | 11000.00 | GFSGERS | A003 | | C00002 | Bolt | New York | New York | USA | 3 | 5000.00 | 7000.00 | 9000.00 | 3000.00 | DDNRDRH | A008 | | C00018 | Fleming | Brisban | Brisban | Australia | 2 | 7000.00 | 7000.00 | 9000.00 | 5000.00 | NHBGVFC | A005 | | C00021 | Jacks | Brisban | Brisban | Australia | 1 | 7000.00 | 7000.00 | 7000.00 | 7000.00 | WERTGDF | A005 | .............. | C00011 | Sundariya | Chennai | Chennai | India | 3 | 7000.00 | 11000.00 | 7000.00 | 11000.00 | PPHGRTS | A010 | +-----------+-------------+-------------+--------------+--------------+-------+-------------+-------------+-------------+---------------+--------------+------------+Sample table: orders
ORD_NUM ORD_AMOUNT ADVANCE_AMOUNT ORD_DATE CUST_CODE AGENT_CODE ORD_DESCRIPTION
---------- ---------- -------------- --------- --------------- --------------- -----------------
200114 3500 2000 15-AUG-08 C00002 A008
200122 2500 400 16-SEP-08 C00003 A004
200118 500 100 20-JUL-08 C00023 A006
200119 4000 700 16-SEP-08 C00007 A010
200121 1500 600 23-SEP-08 C00008 A004
200130 2500 400 30-JUL-08 C00025 A011
200134 4200 1800 25-SEP-08 C00004 A005
200108 4000 600 15-FEB-08 C00008 A004
200103 1500 700 15-MAY-08 C00021 A005
...........
200102 2000 300 25-MAY-08 C00012 A012
To get 'agent_code', 'ord_num', 'ord_amount' and 'cust_code' from the 'orders' table, with following condition -
1. any agent of 'customer' table not having a 'payment_amt' is 1400,
the following sql statement can be used:
SELECT agent_code,ord_num,ord_amount,cust_code
FROM orders a
WHERE NOT EXISTS(
SELECT agent_code
FROM customer
WHERE payment_amt=1400 AND a.cust_code=cust_code);
Output:
AGENT_CODE ORD_NUM ORD_AMOUNT CUST_C ---------- ---------- ---------- ------ A005 200134 4200 C00004 A007 200112 2000 C00016 A004 200122 2500 C00003 A008 200111 1000 C00020 A008 200114 3500 C00002 A002 200133 1200 C00009 A002 200128 3500 C00009 A002 200120 500 C00009 A010 200109 3500 C00011 A004 200108 4000 C00008 A004 200121 1500 C00008 A002 200113 4000 C00022 A002 200126 500 C00022 A002 200123 500 C00022 A006 200129 2500 C00024 ........ ........
Check out our 1000+ SQL Exercises with solution and explanation to improve your skills.
PREV : SQL SOME Operator
NEXT : SQL LIKE Operator