Answer Posted / vipul dalwala

For emample we have table called DUPtable.

DESCRIBE DUPtable;

+--------+-----------------+
| Field | Type |
+--------+-----------------+
| id | Auto Increament |
| field1 | varchar(20) |
| field2 | varchar(20) |
| field3 | varchar(20) |
+--------+-----------------+

And we want to delete duplicate rows from DUPtable (Same
combination of field1, field2 and field3) .

Solution:

Step 1: Create a Temporary table;

CREATE TEMPORARY TABLE tmpDUPtable
SELECT id FROM DUPtable GROUP BY field1, field2, field3;


Step 2: Delete query to remove Rows not in 'tmpDUPtable'
table.

DELETE from DUPtable WHERE id NOT IN (SELECT id FROM
tmpDUPtable);

Step 3 DROP tmpDUPtable

DROP TABLE tmpDUPtable;


I hope this will help.

What does mysqli_query return?

917

---

Which character is used to match exactly one character?

960

---

Can I use node js with php?

995

---

What is curl php?

980

---

Tell me what are the __construct() and __destruct() methods in a php class?

967

---

Tell me what is the importance of "action" attribute in a html form?

1063

---

Which is better #define or enum?

928

---

What is smarty?

923

---

Explain what is meant by pear in php?

971

---

What is the php function that removes the first element of the array and returns it?

945

---

How do you display the output directly to the browser?

890

---

How to run a php script?

963

---

What is php variable?

973

---

Can php run on windows server?

983

---

Why do we use javascript in php?

937

---