Mysql将数据从一个表插入另一个表

Question

INSERT INTO table2 (firstname, lastname, middlename) SELECT firstname, lastname FROM table1 WHERE id = 1

如何为table2'middlename'列插入数据？在我的table1中，只有两列'firstname'和'lastname'

Answer 1

从列表中删除middlename列：

INSERT INTO table2 (firstname,lastname) 
SELECT firstname, lastname FROM table1 WHERE id = 1

Answer 2

尝试此查询

INSERT INTO table2 (firstname, lastname, middlename) SELECT firstname, lastname, "NA" FROM table1 WHERE id = 1

Answer 3

INSERT INTO table2 (firstname,lastname) SELECT firstname, lastname FROM table1

将table2中的中间名留空，因为你没有

的记录

Answer 4

如果它是必填列（即NOT NULL且未定义默认值），则必须选择常量。 像

这样的东西

insert into table2 (firstname, lastname, middlename)
select firstname, lastname, 'N/A' from table1 where id = 1;

如果列是可选的，请忽略列列表中的列。像

insert into table2 (firstname, lastname)
select firstname, lastname from table1 where id = 1;