更新 MySQL 中具有 JSON 格式的列?


要以 JSON 格式显示记录,请使用 MySQL concat()。我们首先创建一个表 −

mysql> create table DemoTable1373
   -> (
   -> StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,
   -> StudentDetails text
   -> );
Query OK, 0 rows affected (0.86 sec)

使用 insert 命令向表中插入一些记录。在这里,我们还没有插入任何内容 −

mysql> insert into DemoTable1373 values();
Query OK, 1 row affected (0.27 sec)
mysql> insert into DemoTable1373 values();
Query OK, 1 row affected (0.08 sec)
mysql> insert into DemoTable1373 values();
Query OK, 1 row affected (0.18 sec)

使用 select 语句从表中显示所有记录 −

mysql> select * from DemoTable1373;

这将生成以下输出 −

+-----------+----------------+
| StudentId | StudentDetails |
+-----------+----------------+
|         1 | NULL           |
|         2 | NULL           |
|         3 | NULL           |
+-----------+----------------+
3 rows in set (0.00 sec)

以下是使用 JSON 格式更新 MySQL 字段的查询 −

mysql> update DemoTable1373 set StudentDetails=concat("{" "StudentName:", " John ,"," StudentAge:", 21,","," StudentCountryName: "," US","} ");
Query OK, 3 rows affected (0.14 sec)
Rows matched: 3  Changed: 3 Warnings: 0

让我们再次检查表记录 −

mysql> select * from DemoTable1373;

这将生成以下输出 −

+-----------+---------------------------------------------------------------+
| StudentId | StudentDetails                                                |
+-----------+---------------------------------------------------------------+
|         1 | {StudentName: John , StudentAge:21, StudentCountryName:  US}  |
|         2 | {StudentName: John , StudentAge:21, StudentCountryName:  US}  |
|         3 | {StudentName: John , StudentAge:21, StudentCountryName:  US}  |
+-----------+---------------------------------------------------------------+
3 rows in set (0.00 sec)

更新于: 11-Nov-2019

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