php 如何判断 MySQL UPDATE 何时成功与实际更新的数据？
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How do I tell when a MySQL UPDATE was successful versus actually updated data?
提问by zechdc
How do I tell when a MySQL UPDATE was successful versus actually updated data?
如何判断 MySQL UPDATE 何时成功与实际更新的数据？
Example:
例子：
TABLE
id city_name
1 Union
2 Marthasville
If I run the following:
如果我运行以下命令：
$data = array('city_name', 'Marthasville');
//update record 2 from Marthasville to the same thing, Marthasville.
$this->db->where('id', 2);
$this->db->update('table', $data);
if($this->db->affected_rows() > 0)
{
//I need it to return TRUE when the MySQL was successful even if nothing was actually updated.
return TRUE;
}else{
return FALSE;
}
This will return TRUEevery time the UPDATE statement is successful, but FALSE when no rows were actually updated.
这将在TRUE每次 UPDATE 语句成功时返回，但在没有实际更新行时返回FALSE。
I need it to return TRUEevery time the UPDATE statement was successfully executed even if it doesn't actually change any records.
TRUE每次成功执行 UPDATE 语句时我都需要它返回，即使它实际上没有更改任何记录。
回答by 472084
Have a look at mysql_affected_rows()
It should tell you if anything was actually updated as opposed to nothing was successfully updated resulting in a return of true.
它应该告诉您是否实际更新了任何内容，而不是没有成功更新导致返回 true。
php.net says:
php.net 说：
mysql_affected_rows()
Returns the number of affected rows on success, and -1 if the last query failed.
mysql_affected_rows()
成功时返回受影响的行数，如果最后一次查询失败，则返回 -1。
You could use the following to achieve your desired results:
您可以使用以下方法来实现您想要的结果：
if($this->db->affected_rows() >= 0){ }
回答by lnguyen55
Then you would use mysql_query:
然后你会使用mysql_query：
SQL statements, INSERT, UPDATE, DELETE, DROP, etc, mysql_query() returns TRUE on success or FALSE on error.
SQL 语句、INSERT、UPDATE、DELETE、DROP 等，mysql_query() 成功时返回 TRUE，错误时返回 FALSE。
Simple like this:
简单像这样：
$result = $this->db->update('table', $data);
if($result)
{
//without error even no row updated
} else {
}
