创建一个mysql记录（如果不存在），否则更新它

Question

I would like to modify this MySQL query to insert the row only if it does not exist. Otherwise, I would like to update the existing row.

<?php
$query = mysql_query("UPDATE hqfjt_email_history SET datesent = ['datesent'],emailformname = ['emailformname'],leadname = ['leadname']
WHERE emailformname = ['emailformname'] AND leadname = ['leadname']") or die(mysql_error());
?>

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ EDIT >>

Would this be correct ?

INSERT INTO hqfjt_email_history datesent = ['datesent'],emailformname =     ['emailformname'],leadname = ['leadname'] ON DUPLICATE KEY UPDATE hqfjt_email_history SET     datesent = ['datesent'],emailformname = ['emailformname'],leadname = ['leadname']
WHERE emailformname = ['emailformname'] AND leadname = ['leadname']

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I have tried the above and get the error : You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'datesent = ['datesent'],emailformname = ['emailformname'],leadname = ['leadname'' at line 1

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

UPDATE ! Ok, I tried this and it creates the record ok :

If I do this though, nothing happens, nothing gets updated or created ???? :

<?php
$query = mysql_query("
INSERT INTO hqfjt_email_history (id, leadname, emailformname, datesent)
VALUES
('$_POST[id]','$_POST[leadname]','$_POST[emailformname]','$_POST[datesent]') ON         DUPLICATE KEY UPDATE hqfjt_email_history (datesent) VALUES ('$_POST[datesent]')     WHERE id = '$_POST[id]'");
?>

Answer 1

Yes, use the INSERT INTO ... ON DUPLICATE KEY UPDATE syntax.

http://dev.mysql.com/doc/refman/5.0/en/insert-on-duplicate.html

You will need to have a key defined on the table of types UNIQUE or PRIMARY KEY .

Answer 2

There is also REPLACE .

Which will update the existing row or will create a new one if it doesn't exist, also the syntax is similar to INSERT .

It does exactly what INSERT ... ON DUPLICATE KEY UPDATE does, but I think this approach is more elegant.

Answer 3

Yeah, use ON DUPLICATE KEY UPDATE

for that. Here is an example:

INSERT INTO <table> (<field1>, <field2>) VALUES (<value1>, <value2>)
ON DUPLICATE KEY UPDATE <field2> = 'update CONTENT';

important is the primary key (underlined in phpMyAdmin table).

Answer 4

read this url

http://dev.mysql.com/doc/refman/5.0/en/insert-on-duplicate.html

check the database emailformname and leadname are unique