CodeIgniter 3.0 Support Database read/write separation mode

There are some methods on the Internet that support read-write separation, but too much copy, and some only support 2.0 version, now improve one, support 3.0 version of read-write separation

The environment for this modification is:

• CodeIgniter 3.0.3

• MySQL 5.5+

• PHP 5.5.9

• Nginx 1.1.8

Step One: Modify application/config/database.php

Configuration of database Read and write connection parameters.

$active _group= ' Default ';$query _builder=TRUE;$db[' Default '] =Array(    ' DSN ' = ' = ', ' hostname ' = ' 127.0.0.1 ', ' username ' + ' root ', ' password ' + = ', ' database ' =&gt ; ' xxx ', ' dbdriver ' = ' mysqli ', ' dbprefix ' = ', ' pconnect 'FALSE, ' Db_debug ' + 1, ' cache_on ' =FALSE, ' cachedir ' = ', ' char_set ' = ' utf8 ', ' dbcollat ' = ' utf8_general_ci ', ' swap_pre ' = ', ' E Ncrypt ' =FALSE, ' compress ' =FALSE, ' Stricton ' =FALSE,//failover Configuring an alternate node' Failover ' =Array(        /* Set up multiple standby database hosts * array (' hostname ' = ' localhost1 ', ' username ' = ' = ', ' Passwo            Rd ' = = ', ' database ' = ', ' dbdriver ' = ' mysqli ', ' dbprefix ' = ', ' ' Pconnect ' = True, ' db_debug ' = = True, ' cache_on ' = FALSE, ' Cachedir ' =&G T            ', ' char_set ' = ' utf8 ', ' dbcollat ' and ' utf8_general_ci ', ' swap_pre ' = ', ' ' Encrypt ' = false, ' compress ' = False, ' Stricton ' and false), array (' hostname ' = ' localhost2 ', ' username ' and ' = ', ' password ' and ' = ', ' da            Tabase ' + ', ' dbdriver ' = ' mysqli ', ' dbprefix ' + ', ' pconnect ' and ' = TRUE ',  ' Db_debug ' + TRUE, ' cache_on ' = FALSE, ' cachedir ' = ', ' Char_set '       = ' UTF8 ',     ' Dbcollat ' = ' utf8_general_ci ', ' swap_pre ' = ', ' encrypt ' and ' = FALSE, ' com Press ' = False, ' Stricton ' = False)*/    ), ' save_queries ' =TRUE);//open $db [' write '] supports read and write separation$db [' write '] = Array (' DSN ' = = ', ' hostname ' = ' 127.0.0.1 ', ' username ' = ' root ', ' password '    = = ', ' database ' = ' xxx ', ' dbdriver ' = ' mysqli ', ' dbprefix ' + ', ' pconnect ' and ' = FALSE ', ' Db_debug ' = 1, ' cache_on ' and FALSE, ' cachedir ' = ', ' char_set ' = ' utf8 ', ' dbcollat ' + ' UT    F8_general_ci ', ' swap_pre ' = ', ' encrypt ' = false, ' compress ' = False, ' Stricton ' = False, Failover Configuration Alternate node ' failover ' = = Array (), ' save_queries ' = TRUE);

Step two, modify system/core/controller.php add the following code

Public $db _write = null;

Step three, modify the system/database/db.php

Found it

$DB->initialize ();

Add on top

//supports read and write separations    if(!Empty($db[' Write '])){        $CI=&get_instance (); $CI->db_write =New $driver($db[' Write ']); $DB->is_single_instance =false; $CI->db_write->is_single_instance =false; $CI->db_write->Initialize (); }Else{        $DB->is_single_instance =true; }

Step four, modify the system/database/db_driver.php

Add a database connection to SQL Select Routing feature.

Add an instance variable

 Public $is _single_instance false;

and replace the following method

 Public functionSimple_query ($sql)    {        if( !$this-conn_id) {            $this-Initialize (); }        if($this-is_single_instance) {            //non-read and write separation            return $this->_execute ($sql); }Else{            //read/write separation            if(Preg_match("/^\s*select/",Strtolower($sql)))            {                return $this->_execute ($sql); }            Else            {                $CI=&get_instance (); //The Main library is selected by default! This is important, and if you have an unknown function, you can keep the data intact.                $rrr=$CI->db_write->_execute ($sql); return $rrr; }        }    }

Step five: If you are using the default mysqli connection, please comment out the following method of system/database/drivers/mysqli/mysqli_driver.php

 Public function insert_id () {
return $this->conn_id->insert_id;

}

and add a new method to the system/database/db_driver.php .

/** * Insert ID * * @return int*/     Public functioninsert_id () {//return $this->conn_id->insert_id;        if($this-is_single_instance) {            return $this->conn_id->insert_id; }Else{            //read/write separation            $CI=&get_instance (); return $CI->db_write->conn_id->insert_id; }    }

Sixth step: Modify The Close method inside the system/database/db_driver.php

/** * Close DB Connection * * @return void*/     Public functionClose () {if($this-is_single_instance) {            if($this-conn_id) {                $this-_close (); $this->conn_id =FALSE; }        }Else{            //read/write separation            $CI=&get_instance (); $CI->db_write->conn_id =FALSE; $this->conn_id =FALSE; }    }

At this point, the CodeIgniter 3.0 perfectly solves the read-write separation operation

This article refers to some of the resources on the Internet

CodeIgniter 3.0 Support Database read/write separation mode