MySqli查询在phpmyadmin中工作，而不是在php脚本中工作

我遇到了一个问题。

我尝试做简单的查询：

        $this->db->query("  INSERT INTO prognosis(stamp,day_ep,day_ep_sum,day_time,day_time_sum,week_ep,week_ep_sum,week_time,week_time_sum,month_ep,month_ep_sum,month_time,month_ep_sum,year_ep,year_ep_sum,year_time,year_time_sum)
                        VALUES('$stamp',$today_ep,$today_ep_sum,$today_time,$today_time_sum,$week_ep,$week_ep_sum,$week_time,$week_time_sum,$month_ep,$month_ep_sum,$month_time,$month_time_sum,$year_ep,$year_ep_sum,$year_time,$year_time_sum)
                    ");

和表仍然是空的，所以我使用echo:将带有值的完整查询打印到html文件（meta字符集=utf-8）

INSERT INTO prognosis ( stamp, day_ep, day_ep_sum, day_time, day_time_sum, week_ep, week_ep_sum, week_time, week_time_sum, month_ep, month_ep_sum, month_time, month_time_sum, year_ep, year_ep_sum, year_time, year_time_sum ) VALUES ( '2016-01-09', 7, 5544, 318, 210948, 53, 5547, 2240, 211040, 289, 5744, 12844, 219835, 3366, 8822, 151232, 358223 )

ctrl+C、ctrl+V到phpmyadmin和表接受该查询（为什么？）

描述：

Array
(
[0] => Array
    (
        [Field] => id
        [Type] => int(11)
        [Null] => NO
        [Key] => PRI
        [Default] => 
        [Extra] => auto_increment
    )
[1] => Array
    (
        [Field] => stamp
        [Type] => date
        [Null] => YES
        [Key] => 
        [Default] => 
        [Extra] => 
    )
[2] => Array
    (
        [Field] => day_ep
        [Type] => int(11)
        [Null] => YES
        [Key] => 
        [Default] => 
        [Extra] => 
    )
[3] => Array
    (
        [Field] => day_ep_sum
        [Type] => int(11)
        [Null] => YES
        [Key] => 
        [Default] => 
        [Extra] => 
    )
[4] => Array
    (
        [Field] => day_time
        [Type] => int(11)
        [Null] => YES
        [Key] => 
        [Default] => 
        [Extra] => 
    )
[5] => Array
    (
        [Field] => day_time_sum
        [Type] => int(11)
        [Null] => YES
        [Key] => 
        [Default] => 
        [Extra] => 
    )
[6] => Array
    (
        [Field] => week_ep
        [Type] => int(11)
        [Null] => YES
        [Key] => 
        [Default] => 
        [Extra] => 
    )
[7] => Array
    (
        [Field] => week_ep_sum
        [Type] => int(11)
        [Null] => YES
        [Key] => 
        [Default] => 
        [Extra] => 
    )
[8] => Array
    (
        [Field] => week_time
        [Type] => int(11)
        [Null] => YES
        [Key] => 
        [Default] => 
        [Extra] => 
    )
[9] => Array
    (
        [Field] => week_time_sum
        [Type] => int(11)
        [Null] => YES
        [Key] => 
        [Default] => 
        [Extra] => 
    )
[10] => Array
    (
        [Field] => month_ep
        [Type] => int(11)
        [Null] => YES
        [Key] => 
        [Default] => 
        [Extra] => 
    )
[11] => Array
    (
        [Field] => month_ep_sum
        [Type] => int(11)
        [Null] => YES
        [Key] => 
        [Default] => 
        [Extra] => 
    )
[12] => Array
    (
        [Field] => month_time
        [Type] => int(11)
        [Null] => YES
        [Key] => 
        [Default] => 
        [Extra] => 
    )
[13] => Array
    (
        [Field] => month_time_sum
        [Type] => int(11)
        [Null] => YES
        [Key] => 
        [Default] => 
        [Extra] => 
    )
[14] => Array
    (
        [Field] => year_ep
        [Type] => int(11)
        [Null] => YES
        [Key] => 
        [Default] => 
        [Extra] => 
    )
[15] => Array
    (
        [Field] => year_ep_sum
        [Type] => int(11)
        [Null] => YES
        [Key] => 
        [Default] => 
        [Extra] => 
    )
[16] => Array
    (
        [Field] => year_time
        [Type] => int(11)
        [Null] => YES
        [Key] => 
        [Default] => 
        [Extra] => 
    )
[17] => Array
    (
        [Field] => year_time_sum
        [Type] => int(11)
        [Null] => YES
        [Key] => 
        [Default] => 
        [Extra] => 
    )

)

我注意到一件有趣的事情：当我试图找到这种行为的原因时，我会尝试执行较短的查询：

        $this->db->query("  INSERT INTO prognosis(stamp,year_ep,year_ep_sum,year_time,year_time_sum)
                        VALUES('$stamp',$year_ep,$year_ep_sum,$year_time,$year_time_sum)

它工作得很好，但我必须执行完整版本的查询。