Question

name table a            
1.budy                  
2.rendy                
3.rona                  
4.sandi
5.susi

table b
1.budy
2.rendy
3.rona

我怎样才能在桌子上用sql显示表b b sandi和susi？

Answer 1

测试：http://rextester.com/HDZ43705

这将满足您的需求：

select * from A 
except 
select * from B

Answer 2

您可以使用TableA中的LEFT JOIN或NOT EXISTS检查TableB中是否存在数据，TableB中不存在，然后插入INSERT INTO tableb(name) SELECT A.name FROM tableA A LEFT JOIN tableB B ON B.name = A.name WHERE B.name IS NULL

SELECT A.name 
FROM tableA A
WHERE NOT EXISTS(SELECT 1 FROM tableB B WHERE B.name = A.name)

或

SET @datetime = '2018-04-22'; SELECT date(datetime) as day ,(CASE WHEN (SELECT content FROM logs WHERE date(datetime) = @datetime ORDER BY datetime LIMIT 1) > (SELECT content FROM logs WHERE date(datetime) = @datetime ORDER BY datetime desc LIMIT 1) THEN min(content) - max(content) ELSE max(content) - min(content) END) as diffN FROM logs WHERE Name = 'Foo' AND date(datetime) = @datetime GROUP BY day(datetime) ORDER BY datetime ;

Answer 3

试一试： -

INSERT INTO tableb
SELECT tablea.id,tablea.name,tableb.id,tableb.name
 FROM tablea
   LEFT JOIN tableb
      ON tablea.name = tableb.name;

Answer 4

可能不是最优化的解决方案，但猜猜它会起作用：

SELECT name 
FROM TableB

UNION

SELECT name 
FROM TableA

如果那是你要查找的（表的连接视图），将在两个表中返回数据的DISTINCT版本。

如果你只想在A中显示不在B中的名字，那么就像这样：

SELECT name FROM TableA WHERE name NOT IN (SELECT name FROM TableB)

我认为这与DEEPAK提出的基本相同，只是他更紧凑和现代。

Answer 5

使用此

INSERT INTO tableb

SELECT tablea.id，tablea.name FROM dbo.tablea

LEFT JOIN dbo.tableb

ON tablea.id = tableb.id

WHERE tableb.id为null

SQL如何插入和左连接

5 个答案: