mysql - Mysql Group_concat 与 concat

Question

我正在使用下面的查询来获取数据，但我得到的结果被截断

SELECT group_concat(concat(`cl`.`payment_info`, '<=>', `cl`.`total_amount`) SEPARATOR '<==>') AS payment_info

Array
(
    [0] => Array
        (
            [payment_info] => [{"payment_date":"12\/12\/2016","payment_percentage":"30.00","payment_status"
:"Paid"},{"payment_date":"13\/12\/2016","payment_percentage":"20.00","payment_status":"Unpaid"},{"payment_date"
:"","payment_percentage":"","payment_status":"Unpaid"},{"payment_date":"","payment_percentage":"","payment_status"
:"Unpaid"},{"payment_date":"","payment_percentage":"","payment_status":"Unpaid"}]<=>0.00<==>[{"payment_date"
:"12\/12\/2016","payment_percentage":"50.00","payment_status":"Paid"},{"payment_date":"13\/12\/2016"
,"payment_percentage":"40.00","payment_status":"Unpaid"},{"payment_date":"","payment_percentage":"","payment_status"
:"Unpaid"},{"payment_date":"","payment_percentage":"","payment_status":"Unpaid"},{"payment_date":"","payment_percentage"
:"","payment_status":"Unpaid"}]<=>548.43<==>[{"payment_date":"12\/12\/2016","payment_percentage":"30
.00","payment_status":"Paid"},{"payment_date":"13\/12\/2016","payment_percentage":"20.00","payment_status"
:"Unpaid"},{"payment_date":"","payment_percentage":"","payment_status":"
        )

)

当数据很大时，我遇到这个问题，否则这个查询工作正常，请告诉我哪里出错了。

付款信息中保存的是json格式数据，金额中保存的是金额。 payment_info 数据类型为文本

Answer 1

您必须设置group_concat_max_len。默认长度为 1024 个字符。请参阅手册信息

group_concat_max_len

Description: Maximum length in bytes of the returned result for a GROUP_CONCAT() function.
Commandline: --group-concat-max-len=#
Scope: Global, Session
Dynamic: Yes
Data Type: numeric
Default Value: 1024
Range - 32-bit: 4 to 4294967295
Range - 64-bit: 4 to 18446744073709547520