Use PHP to implement Mysql read/write splitting

This code is modified from the uchome code because it needs to solve the uchome efficiency. This thinking has actually existed for a long time, but it has never been done. I believe some people have the same idea. If there is a similar idea, I really hope to put forward relevant suggestions.

The encapsulation method is simple, and the interface extension of the read-only database connection is added. The use of the original code is not affected if the read-only database is not used. It remains to be improved in the future ..
For convenience, I tried to build a google Project:
Http://code.google.com/p/mysql-rw-php/
Hope to help friends in need.

Mysql read/write splitting implemented by PHP
Main features:
1. Simple read/write splitting
2. You can add more read-only databases to a primary database.
3. read/write splitting, but do not worry about unsupported features
4. Disadvantages: connecting two databases at the same time
Poor English. Just write a few words.
Php code for mysql read/write split
Feature:
Simply rw split
One master, can add more slaves
Support all mysql feature
Link to the master and slave at the same time
PHP code:
Mysql_rw_php.class.php

Copy codeThe Code is as follows: <? Php
/*************************************** *
* ** Mysql-rw-php version 0.1
* ** Code by hqlulu # gmail.com
* ** Http://www.aslibra.com
* ** Http://code.google.com/p/mysql-rw-php/
* ** Code modify from class_mysql.php (uchome)
****************************************/
Class mysql_rw_php {
// Number of queries
Var $ querynum = 0;
// The current database connection
Var $ link = null;
// Character Set
Var $ charset;
// Current Database
Var $ cur_db = '';
// Check whether a valid read-only database connection exists
Var $ ro_exist = false;
// Read-only database connection
Var $ link_ro = null;
// Read/write database connection
Var $ link_rw = null;
Function mysql_rw_php (){
}
Function connect ($ dbhost, $ dbuser, $ dbpw, $ dbname = '', $ pconnect = 0, $ halt = TRUE ){
If ($ pconnect ){
If (! $ This-> link = @ mysql_pconnect ($ dbhost, $ dbuser, $ dbpw )){
$ Halt & $ this-> halt ('can not connect to MySQL Server ');
}
} Else {
If (! $ This-> link = @ mysql_connect ($ dbhost, $ dbuser, $ dbpw )){
$ Halt & $ this-> halt ('can not connect to MySQL Server ');
}
}

// Read-only connection failed
If (! $ This-> link &&! $ Halt) return false;

// If rw is not initialized, the first connection acts as rw
If ($ this-> link_rw = null)
$ This-> link_rw = $ this-> link;
If ($ this-> version ()> '4. 1 '){
If ($ this-> charset ){
@ Mysql_query ("SET character_set_connection = $ this-> charset, character_set_results = $ this-> charset, character_set_client = binary", $ this-> link );
}
If ($ this-> version ()> '5. 0.1 '){
@ Mysql_query ("SET SQL _mode ='' ", $ this-> link );
}
}
If ($ dbname ){
$ This-> select_db ($ dbname );
}
}
// Connect to a read-only mysql database
Function connect_ro ($ dbhost, $ dbuser, $ dbpw, $ dbname = '', $ pconnect = 0 ){
If ($ this-> link_rw = null)
$ This-> link_rw = $ this-> link;
$ This-> link = null;
// No halt Error
$ This-> connect ($ dbhost, $ dbuser, $ dbpw, $ dbname, $ pconnect, false );
If ($ this-> link ){
// Connection successful
// Echo "link ro sussess! <Br> ";
$ This-> ro_exist = true;
$ This-> link_ro = $ this-> link;
If ($ this-> cur_db ){
// If you have already selected a database, you need to perform the operation once.
@ Mysql_select_db ($ this-> cur_db, $ this-> link_ro );
}
} Else {
// Connection failed
// Echo "link ro failed! <Br> ";
$ This-> link = & $ this-> link_rw;
}
}
// Set a series of read-only databases and connect to one of them
Function set_ro_list ($ ro_list ){
If (is_array ($ ro_list )){
// Select one of them randomly
$ Link_ro = $ ro_list [array_rand ($ ro_list)];
$ This-> connect_ro ($ link_ro ['dbhost'], $ link_ro ['dbuser'], $ link_ro ['dbpw ']);
}
}
Function select_db ($ dbname ){
// Operate the connection between the two databases at the same time
$ This-> cur_db = $ dbname;
If ($ this-> ro_exist ){
@ Mysql_select_db ($ dbname, $ this-> link_ro );
}
Return @ mysql_select_db ($ dbname, $ this-> link_rw );
}
Function fetch_array ($ query, $ result_type = MYSQL_ASSOC ){
Return mysql_fetch_array ($ query, $ result_type );
}
Function fetch_one_array ($ SQL, $ type = ''){
$ Qr = $ this-> query ($ SQL, $ type );
Return $ this-> fetch_array ($ qr );
}
Function query ($ SQL, $ type = ''){
$ This-> link = & $ this-> link_rw;
// Determine whether a select statement is used
If ($ this-> ro_exist & preg_match ("/^ (\ s *) select/I", $ SQL )){
$ This-> link = & $ this-> link_ro;
}
$ Func = $ type = 'unbuffered' & @ function_exists ('mysql _ unbuffered_query ')?
'Mysql _ unbuffered_query ': 'mysql _ query ';
If (! ($ Query = $ func ($ SQL, $ this-> link) & $ type! = 'Silent '){
$ This-> halt ('mysql Query error', $ SQL );
}
$ This-> querynum ++;
Return $ query;
}
Function affected_rows (){
Return mysql_affected_rows ($ this-> link );
}
Function error (){
Return ($ this-> link )? Mysql_error ($ this-> link): mysql_error ());
}
Function errno (){
Return intval ($ this-> link )? Mysql_errno ($ this-> link): mysql_errno ());
}
Function result ($ query, $ row ){
$ Query = @ mysql_result ($ query, $ row );
Return $ query;
}
Function num_rows ($ query ){
$ Query = mysql_num_rows ($ query );
Return $ query;
}
Function num_fields ($ query ){
Return mysql_num_fields ($ query );
}
Function free_result ($ query ){
Return mysql_free_result ($ query );
}
Function insert_id (){
Return ($ id = mysql_insert_id ($ this-> link)> = 0? $ Id: $ this-> result ($ this-> query ("SELECT last_insert_id ()"), 0 );
}
Function fetch_row ($ query ){
$ Query = mysql_fetch_row ($ query );
Return $ query;
}
Function fetch_fields ($ query ){
Return mysql_fetch_field ($ query );
}
Function version (){
Return mysql_get_server_info ($ this-> link );
}
Function close (){
Return mysql_close ($ this-> link );
}
Function halt ($ message = '', $ SQL = ''){
$ Dberror = $ this-> error ();
$ Dberrno = $ this-> errno ();
Echo "<div style = \" position: absolute; font-size: 11px; font-family: verdana, arial; background: # EBEBEB; padding: 0.5em; \ ">
<B> MySQL Error </B> <br>
<B> Message </B>: $ message <br>
<B> SQL </B>: $ SQL <br>
<B> Error </B>: $ dberror <br>
<B> Errno. </B>: $ dberrno <br>
</Div> ";
Exit ();
}
}
?>