Question

如何获取nname为＆＃34; new5＆＃34;的表名。在所有表中？。我已经尝试了下面的查询，但我没有得到解决方案（我不认为查询是对的）。我真的很感激任何帮助。谢谢你提前。

CREATE TABLE if not exists tblC1
(
id int(11) NOT NULL auto_increment ,
nname varchar(255),
 PRIMARY KEY (id)
);

INSERT INTO tblC1 (id, nname) VALUES
('1', 'new1'),
('2', 'new2'),
('3', 'new3'),
('4', 'new4'),
('5', 'new5');


CREATE TABLE if not exists tblC2
(
id int(11) NOT NULL auto_increment ,
nname varchar(255),
 PRIMARY KEY (id)
);

INSERT INTO tblC2 (id, nname) VALUES
('1', 'new1'),
('2', 'new21'),
('3', 'new31'),
('4', 'new41'),
('5', 'new51');

CREATE TABLE if not exists tblC3
(
id int(11) NOT NULL auto_increment ,
nname varchar(255),
 PRIMARY KEY (id)
);

INSERT INTO tblC3 (id, nname) VALUES
('1', 'new1'),
('2', 'new21'),
('3', 'new31'),
('4', 'new41'),
('5', 'new5');

查询：

SELECT  * 
FROM (SELECT  * FROM   tblC1 
      UNION SELECT * FROM tblC2  
      UNION SELECT * FROM tblC3 ) as t2  
where nname = "new5"

Answer 1

将表名添加到您的单个选择中：

SELECT * FROM (
    SELECT 
        'tblC1' as tbl, tblC1.*
     FROM   tblC1 
      UNION SELECT 'tblC2', tblC2.* FROM tblC2  
      UNION SELECT 'tblC3', tblC3.* FROM tblC3 
) t
where t.nname = "new5"

应该这样做。对于每个联合选择，您需要外部选择或where子句。而且你必须指定表名，

Fiddle

获取列中变量匹配的表名

1 个答案: