http://www.cnblogs.com/chuanzhang053/p/9139624.html
需求描述:
今天看mysql中的json数据类型,涉及到一些使用,使用到了函数json_extract来
获取json字段中某个key的值,在此记录下.
操作过程:
| 2 | {"Tel": "13390989765", "name": "Mike", "address": "Guangzhou"} |
+----+----------------------------------------------------------------+
2 rows in set (0.00 sec)
备注:data字段就是json的数据类型,由键值对组成.
备注:这个查询时直接对json对象进行操作.
3.对tab_json表使用json_extract函数
mysql> select json_extract(data,'$.name') from tab_json;
+-----------------------------+
| json_extract(data,'$.name') |
+-----------------------------+
| "david" |
| "Mike" |
+-----------------------------+
2 rows in set (0.00 sec)
mysql> select json_extract(data,'$.name'),json_extract(data,'$.tel') from tab_json; #如果查询没有的key,那么是可以查询,不过返回的是NULL.
+-----------------------------+----------------------------+
| json_extract(data,'$.name') | json_extract(data,'$.tel') |
+-----------------------------+----------------------------+
| "david" | NULL |
| "Mike" | NULL |
+-----------------------------+----------------------------+
2 rows in set (0.00 sec)
mysql> select json_extract(data,'$.name'),json_extract(data,'$.address') from tab_json;
+-----------------------------+--------------------------------+
| json_extract(data,'$.name') | json_extract(data,'$.address') |
+-----------------------------+--------------------------------+
| "david" | "Beijing" |
| "Mike" | "Guangzhou" |
+-----------------------------+--------------------------------+
2 rows in set (0.00 sec)
备注:通过json_extract函数,获取到了json对象的特定key的值.