php - 如果右连接不返回任何行，则 mysql 设置为 null 或 0

Question

我有以下查询，它不返回任何行。但是，如果发生这种情况，我想将值设置为 0 或 null。我该怎么做呢？

UPDATE `hdb`.`projects` 
RIGHT JOIN (
  SELECT jobs.PROJID, round(SUM(jobs.value),2) AS SumOfJobValues, round(Sum(jobs.Earned),2) AS SumOfEarnedValues 
  FROM jobs
  WHERE projects.PROJID = 1312184
  GROUP BY jobs.PROJID
) as temp ON projects.PROJID = temp.PROJID
SET 
  projects.VALUE = round(SumOfJobValues,2), 
  projects.WIP = round(SumOfEarnedValues,2)

我重写了使用左连接的查询，它在 mysql 中工作。但是，当我使用 php Yii 框架运行它时，我无法正常工作。

UPDATE `hdb`.`projects` 
left JOIN (
  SELECT 
    jobs.PROJID, 
    round(SUM(jobs.value),2) AS SumOfJobValues,
    round(Sum(jobs.Earned),2) AS SumOfEarnedValues 
  FROM jobs         
  GROUP BY jobs.PROJID
) as temp ON projects.PROJID = temp.PROJID
SET 
  projects.VALUE = round(SumOfJobValues,2), 
  projects.WIP = round(SumOfEarnedValues,2)
WHERE projects.PROJID = 1312184

在 php Yii 上运行相同的查询

$sql = "UPDATE `hdb`.`projects` 
   LEFT JOIN (
     SELECT 
       jobs.PROJID, round(SUM(jobs.value),2) AS SumOfJobValues,
       round(Sum(jobs.Earned),2) AS SumOfEarnedValues 
     FROM jobs  
     WHERE jobs.PROJID = :pid                                       
     GROUP BY jobs.PROJID
     as temp ON projects.PROJID = temp.PROJID                               
     SET
       projects.VALUE = round(SumOfJobValues,2), 
       projects.WIP = round(SumOfEarnedValues,2)
     WHERE projects.PROJID = :pid";

$command=$connection->createCommand($sql);
$command->bindValue(":pid",$model->PROJID,PDO::PARAM_INT);
$command->execute();

Answer 1

你忘记在 Yii 查询的第 10 行之前关闭括号。此外，如果您不想加入 NULL 值，则可以在 JOIN 定义中使用“IS NOT NULL”，例如：

UPDATE `hdb`.`projects` 
left JOIN (
  SELECT 
    jobs.PROJID, 
    round(SUM(jobs.value),2) AS SumOfJobValues,
    round(Sum(jobs.Earned),2) AS SumOfEarnedValues 
  FROM jobs         
  GROUP BY jobs.PROJID
) as temp ON (projects.PROJID = temp.PROJID) AND (temp.PROJID IS NOT NULL)
SET 
  projects.VALUE = round(SumOfJobValues,2), 
  projects.WIP = round(SumOfEarnedValues,2)
WHERE projects.PROJID = 1312184

编辑：不过，我还没有测试过。