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I_am_feminist
Asked: 2017-04-28 20:53:31 +0800 CST

如何将值插入到添加到现有表中的新列中？

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SQL 截图 如果您知道如何将值插入到添加到现有表中的新列中，请回答我。您的回答将不胜感激

mysql

1 个回答

  1. Best Answer

    您需要更新现有表。

    mysql> create table tbl1(id int);
Query OK, 0 rows affected (0.04 sec)

mysql> insert into tbl1 values(1);
Query OK, 1 row affected (0.00 sec)

mysql> insert into tbl1 values(2);
Query OK, 1 row affected (0.00 sec)

mysql> alter table tbl1 add column name varchar(20);
Query OK, 0 rows affected (0.13 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> select * from tbl1;
+------+------+
| id   | name |
+------+------+
|    1 | NULL |
|    2 | NULL |
+------+------+
2 rows in set (0.00 sec)

mysql> update tbl1 set name='Jay' where id=1;
Query OK, 1 row affected (0.09 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from tbl1;
+------+------+
| id   | name |
+------+------+
|    1 | Jay  |
|    2 | NULL |
+------+------+
2 rows in set (0.00 sec)

mysql> update tbl1 set name='Joe' where id=2;
Query OK, 1 row affected (0.01 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from tbl1;
+------+------+
| id   | name |
+------+------+
|    1 | Jay  |
|    2 | Joe  |
+------+------+
2 rows in set (0.00 sec)
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