CI数据库类

文章目录

今天在查看CI的用户指南数据库类时，提示连接多个数据库时要用

$DB1 = $this->load->database('group_one', TRUE);
$DB2 = $this->load->database('group_two', TRUE);

通过设置函数的第二个参数为TRUE(boolean)来返回一个数据库对象。

当你使用这种方法，你将用对象名来执行操作命令而不是用户向导模式，也就是说，你将用以下方式执行数据库操作：

$DB1->query();
$DB1->result();
etc...

而不是：

$this->db->query();
$this->db->result();
etc...

译注：要连接多个数据库请先设置 config/database.php 中的 $db[‘xxxxxx’][‘pconnect’] = FALSE; 这是 mysql_pconnect() 造成的问题，和 CI 无关。

我借用BI项目测试后返回一个对象，具体内容是这样的：

CI_DB_mysql_driver Object
    (
        [dbdriver] => mysql
        [_escape_char] => `
        [_like_escape_str] => 
        [_like_escape_chr] => 
        [delete_hack] => 1
        [_count_string] => SELECT COUNT(*) AS 
        [_random_keyword] =>  RAND()
        [use_set_names] => 
        [ar_select] => Array
            (
            )

        [ar_distinct] => 
        [ar_from] => Array
            (
            )

        [ar_join] => Array
            (
            )

        [ar_where] => Array
            (
            )

        [ar_like] => Array
            (
            )

        [ar_groupby] => Array
            (
            )

        [ar_having] => Array
            (
            )

        [ar_keys] => Array
            (
            )

        [ar_limit] => 
        [ar_offset] => 
        [ar_order] => 
        [ar_orderby] => Array
            (
            )

        [ar_set] => Array
            (
            )

        [ar_wherein] => Array
            (
            )

        [ar_aliased_tables] => Array
            (
            )

        [ar_store_array] => Array
            (
            )

        [ar_caching] => 
        [ar_cache_exists] => Array
            (
            )

        [ar_cache_select] => Array
            (
            )

        [ar_cache_from] => Array
            (
            )

        [ar_cache_join] => Array
            (
            )

        [ar_cache_where] => Array
            (
            )

        [ar_cache_like] => Array
            (
            )

        [ar_cache_groupby] => Array
            (
            )

        [ar_cache_having] => Array
            (
            )

        [ar_cache_orderby] => Array
            (
            )

        [ar_cache_set] => Array
            (
            )

        [ar_no_escape] => Array
            (
            )

        [ar_cache_no_escape] => Array
            (
            )

        [username] => root
        [password] => 
        [hostname] => localhost
        [database] => ga
        [dbprefix] => 
        [char_set] => utf8
        [dbcollat] => utf8_general_ci
        [autoinit] => 1
        [swap_pre] => 
        [port] => 
        [pconnect] => 
        [conn_id] => Resource id #112
        [result_id] => Resource id #113
        [db_debug] => 1
        [benchmark] => 0.00244402885437
        [query_count] => 1
        [bind_marker] => ?
        [save_queries] => 1
        [queries] => Array
            (
                [0] => SELECT *
					FROM (`apps`)
					WHERE `appid` =  1009
            )

        [query_times] => Array
            (
                [0] => 0.00244402885437
            )

        [data_cache] => Array
            (
            )

        [trans_enabled] => 1
        [trans_strict] => 1
        [_trans_depth] => 0
        [_trans_status] => 1
        [cache_on] => 
        [cachedir] => 
        [cache_autodel] => 
        [CACHE] => 
        [_protect_identifiers] => 1
        [_reserved_identifiers] => Array
            (
                [0] => *
            )

        [stmt_id] => 
        [curs_id] => 
        [limit_used] => 
        [stricton] => 
    )

变量非常多，例如 [queries] 也会记录着查询过的语句，[query_time] 记录着相应语句查询所需要的时间等等。