Warning: file_get_contents(/data/phpspider/zhask/data//catemap/8/mysql/59.json): failed to open stream: No such file or directory in /data/phpspider/zhask/libs/function.php on line 167

Warning: Invalid argument supplied for foreach() in /data/phpspider/zhask/libs/tag.function.php on line 1116

Notice: Undefined index: in /data/phpspider/zhask/libs/function.php on line 180

Warning: array_chunk() expects parameter 1 to be array, null given in /data/phpspider/zhask/libs/function.php on line 181

Warning: file_get_contents(/data/phpspider/zhask/data//catemap/4/json/15.json): failed to open stream: No such file or directory in /data/phpspider/zhask/libs/function.php on line 167

Warning: Invalid argument supplied for foreach() in /data/phpspider/zhask/libs/tag.function.php on line 1116

Notice: Undefined index: in /data/phpspider/zhask/libs/function.php on line 180

Warning: array_chunk() expects parameter 1 to be array, null given in /data/phpspider/zhask/libs/function.php on line 181
查询持有JSON的MYSQL长文本_Mysql_Json - Fatal编程技术网

查询持有JSON的MYSQL长文本

查询持有JSON的MYSQL长文本,mysql,json,Mysql,Json,我有一个具有以下结构的表: CREATE TABLE `Event` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(255) NOT NULL, `created` datetime(6) NOT NULL, `last_updated` datetime(6) NOT NULL, `info` longtext NOT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUT

我有一个具有以下结构的表:

CREATE TABLE `Event` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) NOT NULL,
  `created` datetime(6) NOT NULL,
  `last_updated` datetime(6) NOT NULL,
  `info` longtext NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=720 DEFAULT CHARSET=latin1
我需要使用
info
列(其中包含JSON字符串)来查询它

如果我质疑它在做什么:

SELECT e.id, e.created, JSON_TYPE(e.info) AS info
  FROM Event e
它在INFO列上返回OBJECT,但如果我尝试获取JSON的特定列,我会收到:

SQL错误[3144][22001]:数据截断:无法从字符集为“binary”的字符串创建JSON值

我正在运行的SQL:

SELECT INFO - > '$User'
  FROM (SELECT e.id, e.created, JSON_TYPE(e.info) AS info
          FROM Event e) as X
将列的类型更改为json不是一个选项

然后您可以尝试更改为json

SELECT info -> '$.User', info_type
  FROM (SELECT e.id, e.created, 
               JSON_TYPE( CAST( info AS JSON ) ) AS info_type, 
               CAST( info AS JSON ) AS info
          FROM Event e) as X
因为JSON值接受函数(
JSON_TYPE()
)中的字符串值不起作用

顺便说一句,对于您的案例,您不需要带JSON类型,只需要带JSON

更新:您也可以通过使用
JSON\u EXTRACT()
作为

SELECT JSON_EXTRACT( CAST( info AS JSON ) , '$.A' ) AS info,
       JSON_TYPE( CAST( info AS JSON ) ) AS info_type
  FROM Event

@BarbarosÖzhan就在我面前!谢谢我会接受你的回答:)我实际上只是使用了cast(没有JSON类型)。。。对于JSON_类型,它是failingsure@Walucas,因为它不返回JSON,而是返回类型。