Question

我有一个SQL Server Express数据库，其中包含一个我不想操作的系统生成的表，所以我创建了另一个表。

TABLE_1

AreaName
Area_1       
Area_2
Area_3
Area_4

TABLE_2

Area_1
Area_2

我想搜索表之间的差异（我已经对它进行了排序）
与Table_1相比，Table_2中丢失的值应作为新行插入。

这可以在一个声明中做到吗？

SELECT 
    MIN (TableName) AS TableName,
    Area 
FROM 
    (SELECT 
        'Table A' AS TableName, 
        Table_2.Area
     FROM Table_2 

     UNION ALL

     SELECT 
        'Table B' AS TableName, 
        Area
     FROM [Table_1]) tmp 
GROUP BY 
   Area
HAVING 
   COUNT(*) = 1 
ORDER BY 
   Area;

这是我现在用来排序的SQL ......

Answer 1

直截了当的做法：

INSERT INTO Table_2 (AreaName)
SELECT AreaName FROM Table_1
WHERE AreaName NOT IN (SELECT AreaName FROM Table_2)

Answer 2

Insert into table1 (columns)
select Columns from table2 a
where not exists(select * from table3 b where a.ID =b.ID)

SQL - 查找表中的差异并插入/更新表缺失值

2 个答案: