tags:

views:

329

answers:

2

Is this the correct way to do it?

DELETE t1, t2, t3, t4 FROM 
  table1 as t1 
  INNER JOIN  table2 as t2 on t1.id = t2.id
  INNER JOIN  table3 as t3 on t1.id=t3.id
  INNER JOIN  table4 as t4 on t1.id=t4.id
  WHERE  t1.username='%s' AND t1.id='%s'

Thank you.

+2  A: 

An easy way to figure it out is to first write it as a query:

SELECT * FROM 
        table1 as t1 
        INNER JOIN  table2 as t2 on t1.id = t2.id
        INNER JOIN  table3 as t3 on t1.id=t3.id
        INNER JOIN  table4 as t4 on t1.id=t4.id
        WHERE  t1.username='%s' AND t1.id='%s'

If you get the results you expect, just replace the Select * with Delete and your table names. Then it would become:

Delete t1, t2, t3, t4 From table1 as t1 
        INNER JOIN  table2 as t2 on t1.id = t2.id
        INNER JOIN  table3 as t3 on t1.id=t3.id
        INNER JOIN  table4 as t4 on t1.id=t4.id
        WHERE  t1.username='%s' AND t1.id='%s'
Jay Askren
Oops, your right. I corrected the answer.
Jay Askren
+2  A: 

Yes, that is correct. It works fine here:

CREATE TABLE table1 (id int, username nvarchar(30));
CREATE TABLE table2 (id int);
CREATE TABLE table3 (id int);
CREATE TABLE table4 (id int);

INSERT INTO table1 VALUES (1, 'Foo'),(2, 'Bar');
INSERT INTO table2 VALUES (1),(2);
INSERT INTO table3 VALUES (1),(2);
INSERT INTO table4 VALUES (1),(2);

SELECT COUNT(*) FROM table1;
2
SELECT COUNT(*) FROM table2;
2
SELECT COUNT(*) FROM table3;
2
SELECT COUNT(*) FROM table4;
2

DELETE t1, t2, t3, t4 FROM
  table1 as t1
  INNER JOIN  table2 as t2 on t1.id = t2.id
  INNER JOIN  table3 as t3 on t1.id=t3.id
  INNER JOIN  table4 as t4 on t1.id=t4.id
  WHERE  t1.username='Foo' AND t1.id='1';

SELECT COUNT(*) FROM table1;
1
SELECT COUNT(*) FROM table2;
1
SELECT COUNT(*) FROM table3;
1
SELECT COUNT(*) FROM table4;
1

If it's not working for you, perhaps you can modify this example to show what problem you are having.

Mark Byers
Is there a difference between what you posted ( i tried) and the answer posted above? :"Delete From table1 as t1 INNER JOIN table2 as t2 on t1.id = t2.id INNER JOIN table3 as t3 on t1.id=t3.id INNER JOIN table4 as t4 on t1.id=t4.id WHERE t1.username='%s' AND t1.id='%s' "-if so, which one is better? thank you
salmane
@salmane: Yeah, the main difference is that other answer doesn't work at all (try it - it gives a syntax error). He's changed it now though.
Mark Byers
Thank You for your help :)
salmane
The real way to say thank you is to mark this question as answered and giving credit to Mark.
Jay Askren