问题描述
我有两张桌子
TABLE1 TABLE2 COLUMN1 COLUMN2 COLUMN1 COLUMN2 John 56 56 A Bob 45 45 B Eva 68 68 C
并且我需要将列添加到一个表中,事实上我将使用函数 join 从其他表中插入新列值
And I need add column to one table with fact I will insert into new column value from other table using function join
TABLE1 COLUMN1 COLUMN2 COLUMN3 John 56 A Bob 45 B Eva 68 C ALTER TABLE [dbo].[Table1] ADD Column3 nvarchar(255); INSERT INTO [dbo].[Table1] (column3) SELECT table2.column2 from [dbo].[Table2] left join [dbo].[table1] on table1.column2 = table2.column1
但是我得到了
TABLE1 COLUMN1 COLUMN2 COLUMN3 John 56 A Bob 45 B Eva 68 C NULL NULL A NULL NULL B NULL NULL C
你能帮我修理我的插入物吗?
Can you help me to fix my insert?
推荐答案
真的需要更新表设置column3
Really you need to UPDATE the table setting column3
UPDATE t1 SET column3 = t2.column2 FROM [dbo].[Table1] t1 JOIN [dbo].[table2] t2 ON t1.column2 = t2.column1