如何在Mysql查询中为有条件的记录提供序列号

Question

我有一张桌子，其中存储了两种类型的产品。一个表用于具有唯一 ID 的单个项目，另一个表用于组合具有相同 ID 的项目组合，如下图所示：

我必须在我的 SQL 中运行更新查询，它会为此提供序列号 Sno。 如果DealCode 相同，则分配相同的序列号，否则递增。请注意，如果DealCode 为 0，则应递增。 0 代表不同的产品。

Answer 1

也许这会对你有所帮助-

您可以通过为此创建存储过程来执行上述任务

假设您有一个名为“product”的表

存储过程定义 --

DELIMITER $$ 
DROP PROCEDURE IF EXISTS assignSerialNo$$ 
CREATE PROCEDURE `assignSerialNo`() 
BEGIN 
DECLARE x  INT; 
DECLARE y  INT; 
DECLARE data  INT; 
DECLARE countNonZeroRecord  INT; 
DECLARE countZeroRecord  INT;

SET x = 1; 
SET countNonZeroRecord = ( SELECT count(*) FROM  product where DealCode != 0 ); 
SET countZeroRecord = ( SELECT count(*) FROM  product where DealCode = 0 );


WHILE x  <= countZeroRecord  DO 
SET data = ( SELECT WebTransactionDetailNo from product WHERE Sno = 0 LIMIT 1 ); 
UPDATE product SET Sno = x WHERE  WebTransactionDetailNo = data; SET  x = x + 1;  
END WHILE;

SET y = 1; 
WHILE y  <= countNonZeroRecord  DO 
SET data = ( SELECT DealCode from product WHERE Sno = 0 AND DealCode !=0 LIMIT 1 ); 
UPDATE product SET Sno = x WHERE  DealCode = data; SET  x = x + 1;  
SET  y = y + 1; 
END WHILE;

END

调用程序设置序列号。使用语法获取记录 -

调用assignSerialNo()

**

对于 PHP：

如果你想用核心 php 完成上述任务，那么你可以使用下面的代码：
希望这个能对您有所帮助

$connection = mysqli_connect("hostName","userName","password","databaseName");
$x=0; 

$nonZeroDealCodeResult = runQuery("SELECT count(*) as countRecords FROM  product where DealCode != 0",$connection);
$zeroDealCodeResult = runQuery("SELECT count(*) as countRecords FROM  product where DealCode = 0",$connection);

while($zeroDealCodeResult['countRecords']) { 
$x++;
$searchQuery = "SELECT WebTransactionDetailNo from product WHERE Sno = 0 AND DealCode = 0  LIMIT 1";
$data = runQuery($searchQuery,$connection);
mysqli_query($connection, "UPDATE product SET Sno = {$x} WHERE  WebTransactionDetailNo = {$data['WebTransactionDetailNo']}"); 
$zeroDealCodeResult['countRecords']--;
}

while($nonZeroDealCodeResult['countRecords']) {
$x++;  
$searchQuery = "SELECT DealCode from product WHERE Sno = 0 AND DealCode !=0 LIMIT 1";
$data = runQuery($searchQuery,$connection);
mysqli_query($connection, "UPDATE product SET Sno = {$x} WHERE  DealCode = {$data['DealCode']}"); 
$nonZeroDealCodeResult['countRecords']--;
}

function runQuery($searchQuery,$connection) {
$dataQuery = mysqli_query($connection, $searchQuery); 
$data = mysqli_fetch_assoc($dataQuery) ;
return $data;
}

?>