MySQL存储过程循环遍历变量并插入临时表

Posted 2023-05-09

【中文标题】MySQL存储过程循环遍历变量并插入临时表

【英文标题】：MySQL stored procedure loop through variables and insert into temporary table

【发布时间】：2018-08-30 15:35:28

【问题描述】：

我有一个存储过程，它运行一个 select 语句，该语句返回一行并将内容插入到临时表中。 select 语句在 where 子句中有 6 个条件语句，我基本上需要遍历 3 组附加条件并将这些结果插入临时表。这是我目前所拥有的：

CREATE DEFINER=`sleuser`@`%` PROCEDURE `CostDashboard`()
BEGIN

create temporary table TempTable (
ProjectID int, 
Phase varchar(100), 
OriginalCommitments float, 
ApprovedCommitmentChanges float, 
CurrentAssigned float, 
PendingScopeChanges float,
EAC float,
PercentComplete float
);

insert into TempTable(
SELECT project_id,
'FP' as Phase,
OriginalCommitments,
ApprovedCommitmentChanges,
OriginalCommitments+ApprovedCommitmentChanges as CurrentAssigned,
sum(ProjectCostBudget.PendingChangeOrders) as PendingScopeChanges

sum(ProjectCost.CurrentWorkCompleted) + 
sum(ProjectCost.EstimateToComplete) as EAC,

(sum(ProjectCost.CurrentWorkCompleted) + 
sum(ProjectCost.EstimateToComplete) / 
(sum(ProjectCostBudget.OriginalContractPrice + 
ProjectCostBudget.RegisteredChangeOrders))) as PercentComplete

FROM `RCLY-DEV`.project

inner join ImportCost on ImportCost.ProjectID = project.pmis
inner join ProjectCostBudget on ProjectCostBudget.ProjectID = 
project.project_id
inner join ProjectCost on ProjectCost.ProjectID = project.project_id

where ImportCost.ProjectID = 'RLCY-BB-01' 
and ImportCost.Task = "020.0000.000"  
and ProjectCostBudget.ProjectID = 2 
and ProjectCostBudget.ServiceNumber = "020.0000.000" 
and ProjectCost.MonthYear != '' 
and ProjectCost.MonthYear like 'July%2018'
);

select * from TempTable
;

END

这可以工作并在 where 子句中插入带有硬编码值的一条记录，但我需要为 3 组变量运行它，所以我创建了一个额外的临时表，如下所示：

|ImpCostID|ImpCostTask |PCBID|PCBServNum  |MonthYear|
-----------------------------------------------------
|XXY-01-01|030.0000.000|3    |030.0000.000|July%2018|
|QWY-01-01|040.0000.000|4    |040.0000.000|May%2018 |
|ZXF-01-01|040.0000.000|5    |050.0000.000|June%2018|

但我不确定如何将这些值集分配给变量，然后遍历它们。有什么建议吗？

【参考方案1】：

尽可能避免 SQL 语句的序列化（可能代价高昂）。在这种情况下，您可以简单地将 JOIN 与参数表一起用于您的实际查询。如果您只是使用临时表 TempTable 为您保存结果，那么您也不需要这样做，因为您可以在一个查询中获得所有结果：

CREATE DEFINER=`sleuser`@`%` PROCEDURE `CostDashboard`()
BEGIN

create temporary table query_params_tmp (
ImpCostID varchar(20),
ImpCostTask varchar(20),
PCBID int,
PCBServNum varchar(20),
MonthYear varchar(20)
);
insert into query_params_tmp values 
('XXY-01-01', '030.0000.000', 3, '030.0000.000', 'July%2018'),
('QWY-01-01', '040.0000.000', 4, '040.0000.000', 'May%2018'),
('ZXF-01-01', '040.0000.000', 5, '050.0000.000', 'June%2018');


SELECT project_id,
  'FP' as Phase,
  OriginalCommitments,
  ApprovedCommitmentChanges,
  OriginalCommitments+ApprovedCommitmentChanges as CurrentAssigned,
  sum(ProjectCostBudget.PendingChangeOrders) as PendingScopeChanges
  sum(ProjectCost.CurrentWorkCompleted) + 
  sum(ProjectCost.EstimateToComplete) as EAC,

  (sum(ProjectCost.CurrentWorkCompleted) + 
  sum(ProjectCost.EstimateToComplete) / 
  (sum(ProjectCostBudget.OriginalContractPrice + 
  ProjectCostBudget.RegisteredChangeOrders))) as PercentComplete
FROM `RCLY-DEV`.project
  join ImportCost on ImportCost.ProjectID = project.pmis
  join ProjectCostBudget on ProjectCostBudget.ProjectID = project.project_id
  join ProjectCost on ProjectCost.ProjectID = project.project_id
  join query_params_tmp qp on 
    qp.ProjectID = ImportCost.ProjectID and 
    qp.ImpCostTask = ImportCost.Task and
    qp.PCBID = ProjectCostBudget.ProjectID and
    ProjectCost.MonthYear like qp.MonthYear
GROUP BY OriginalCommitments, ApprovedCommitmentChanges;

END

【讨论】：

我喜欢这个思考过程，但是当我运行它时它返回 0 条记录。

临时表填充中有错字。你可以再试一次。如果没有返回想要的结果，请以 SQLFiddle 的形式提供示例数据。

我实际上是在跑步之前抓住了这一点。我会尝试在 SQL Fiddle 中加入一些东西

【参考方案2】：

如果我正确理解了你的问题，那么下面将解决。

使用标识列创建临时表，然后将数据插入其中。如果临时表没有唯一列，这将有助于遍历每条记录

--declare variable
DECLARE @ID INT, 
        @Task VARCHAR(256),
        @ProjectID INT,
        ...
        ...
        ...

SELECT @ID = MIN(ID)
FROM TemporaryTable

WHILE ISNULL(@ID, '') <> ''
BEGIN
    SELECT @Task = ImpCostTask
          ,@ProjectID = PCBID
            ...
            ...
            ...
    FROM TemporaryTable
    WHERE ID = @ID

    insert into TempTable(
    SELECT project_id,
    'FP' as Phase,
    OriginalCommitments,
    ApprovedCommitmentChanges,
    ....
    ....
    ....
    ....
    FROM `RCLY-DEV`.project
    inner join ImportCost on ImportCost.ProjectID = project.pmis
    inner join ProjectCostBudget on ProjectCostBudget.ProjectID = project.project_id
    inner join ProjectCost on ProjectCost.ProjectID = project.project_id
    where ImportCost.ProjectID = @ProjectID
    and ImportCost.Task = @Task
    and ProjectCostBudget.ProjectID = @ProjectID
    ....
    ....
    ....
    ....
    ....
    ....
    ....
    );

    SELECT @ID = MIN(ID)
    FROM TemporaryTable
    WHERE ID > @ID
END

【讨论】：

语法适用于 MSSQL，而问题适用于 mysql