Question

我想插入一行，如果该行不存在且存在，我想更新该行。我目前正在使用mysql 5.1.67

这是我的MYSQL代码：

IF EXISTS(select * from tabSingles where `doctype` = 'Control Panel' and `field` = 'time_zone') 
THEN
update tabSingles SET `value` = 'Asia/Calcutta' where `doctype` = 'Control Panel' and `field` = 'time_zone'
ELSE 
insert into tabSingles (`doctype`,`field`,`value`) VALUES ('Control Panel','time_zone','Asia/Calcutta')

但这总是会引发错误：

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'IF EXISTS(select * from tabSingles where `doctype` = 'Control Panel' AND `fi' at line 1

我知道我可以使用＆＃34; REPLACE＆＃34;或＆＃34; INSERT .... ON DUPLICATE KEY＆＃34;执行此操作但问题是此表中没有PRIMARY KEY或UNIQUE KEY，并且我正在处理的项目是OPEN-SOURCE，因此我们无法更改DATABASE SCHEMA。如果我们这样做，那么每次我们从他们那里得到新的更新时我们都必须继续这个过程。

所以任何人都可以帮助我。

由于

Answer 1

试试这个。

IF EXISTS(SELECT * FROM tabSingles WHERE `doctype` LIKE 'Control Panel' AND `field` LIKE 'time_zone'); 
 BEGIN 
  UPDATE tabSingles SET `value` = 'Asia/Calcutta' WHERE `doctype` LIKE 'Control Panel' AND `field` LIKE 'time_zone' 
 END;
ELSE 
 BEGIN 
      INSERT INTO tabSingles (`doctype`,`field`,`value`) VALUES ('Control Panel','time_zone','Asia/Calcutta') 
 END IF;

OR

IF NOT EXISTS(SELECT * FROM [tabSingles] WHERE `doctype` LIKE 'Control Panel' AND `field` LIKE 'time_zone'); 
 BEGIN 
  INSERT INTO [tabSingles] (`doctype`,`field`,`value`) VALUES ('Control Panel','time_zone','Asia/Calcutta');
 END;
ELSE  
  BEGIN 
    UPDATE [tabSingles] SET `value` = 'Asia/Calcutta' WHERE `doctype` LIKE 'Control Panel' AND `field` LIKE 'time_zone'  
  END IF;

或者，手动试用

$result = mysql_query("SELECT * FROM tabSingles WHERE `doctype` LIKE 'Control Panel' AND `field` LIKE 'time_zone';");       
IF (mysql_affected_rows()==0) 
{
 $result = mysql_query("INSERT INTO tabSingles (`doctype`,`field`,`value`) VALUES ('Control Panel','time_zone','Asia/Calcutta');");
}  
ELSE 
{
 $result = mysql_query("UPDATE tabSingles SET `value` = 'Asia/Calcutta' WHERE `doctype` LIKE 'Control Panel' AND `field` LIKE 'time_zone';"); 
}

Answer 2

Replace首先删除行（通过唯一索引），然后插入一个新行。如果您愿意，可以手动执行此操作，而不是通过唯一索引。如果没有要删除的行，那就没问题了。这和replace一样贵，只要确保你有一个适当的删除索引，你就可以了。

DELETE FROM tabsingles 
WHERE ` doctype ` = 'Control Panel' 
      AND ` field ` = 'time_zone'; 

INSERT INTO tabsingles 
            ( ` doctype ` , 
             ` field ` , 
             ` value ` ) 
VALUES      ('Control Panel', 
             'time_zone', 
             'Asia/Calcutta');

如果没有插入或更新

2 个答案: