Can I switch database with mysql_select_db?

Question

Will this works, or should I disconnect first?

<?php
mysql_connect('localhost','root','');
mysql_select_db('DB1');
//Code... 
//Now I need to change of db
mysql_select_db('DB2');
//More code...

I know mysql() is being deprecated, but I'm working with a old (not so much) system. Thanks!

just one recommendation. don't use the ancient `mysql` functions. use `mysqli` instead — aacanakin, Mar 13 '13 at 14:02
@deceze Not yet. I'm a little busy for now. I'm still thinking about my next activity. — Keoma Borges, Mar 13 '13 at 14:08
@aacanakin As I told, all of this system was used the mysql(). I can't change this. — Keoma Borges, Mar 13 '13 at 14:09
@user2132073 - So lets get this straight - You do not have a particular problem that you have encountered. just on the off chance you post a question. I just hope you do not treat your co-workers in the same fashion. Well -1 for that — Ed Heal, Mar 13 '13 at 14:12

score 1 · Answer 1 · answered Mar 13 '13 at 14:04

1

The documentation say yes:

Ref: http://php.net/manual/en/function.mysql-select-db.php

All queries will run on the current active database, at this case DB2.

Sets the current active database on the server that's associated with the specified link identifier. Every subsequent call to mysql_query() will be made on the active database.

answered Mar 13 '13 at 14:04

GarouDan

3,743
9
49
75

Thanks. I'm reading the docs now. – Keoma Borges Mar 13 '13 at 14:13

score 1 · Answer 2 · answered Mar 13 '13 at 14:04

1

You can use it in sql like

SELECT `database`.`table`.`value` FROM `database`.`table`

answered Mar 13 '13 at 14:04

user1692333

2,461
5
32
64

This would mean she has to update each SQL query. – Bart Friederichs Mar 13 '13 at 14:06
I know, but I'd lose so many time re-writing the querys. – Keoma Borges Mar 13 '13 at 14:10

score 1 · Answer 3 · answered Mar 13 '13 at 14:06

1

The docs say:

Sets the current active database on the server that's associated with the specified link identifier. Every subsequent call to mysql_query() will be made on the active database.

So yes. I guess it is comparable to a use <database> command on the client.

answered Mar 13 '13 at 14:06

Bart Friederichs

33,050
15
95
195

I see. Thanks. For a moment, I've forgotten the docs. – Keoma Borges Mar 13 '13 at 14:12

score 0 · Answer 4 · answered Mar 13 '13 at 14:07

0

you can have more than one active connection

$db1=mysql_connect('localhost','root','');
mysql_select_db('DB1', $db1);

$db2=mysql_connect('localhost','root','');
mysql_select_db('DB2', $db2);

mysql_query("SELECT * FROM table", $db1);
mysql_query("SELECT * FROM table", $db2);

answered Mar 13 '13 at 14:07

Waygood

2,657
2
15
16

see Bart Friederichs link indentifier answer – Waygood Mar 13 '13 at 14:08

Can I switch database with mysql_select_db?

4 Answers4