逐行更新SQL表中的数据

我正在使用SQLServer2008R2。我有一个链接服务器的视图[EmployeeMaster]和数据库中的表[EmployeeDetails]。我有一个每天早上12点运行的服务，它调用一个存储过程来同步表和视图。即，存储过程检查[EmployeeDetails]中的每一行，并使用视图中的匹配行更新该行。我的存储过程是这样的

CREATE PROCEDURE usp_OracleSyncUpdate
AS

CREATE TABLE #ActiveEmployees (
 RowID int IDENTITY(1, 1), 
 [EmployeeId] nvarchar(50),
)
DECLARE @NumberRecords int, @RowCount int
DECLARE @EmployeeId nvarchar(50)
        ,@EmployeeName nvarchar(50)
        ,@EmployeeLastName nvarchar(50)
        ,@EmployeeCategory nvarchar(50)
        ,@ContactNo nvarchar(50)
        ,@Email nvarchar(50)
        ,@Gender nvarchar(50)
        ,@JoiningDate DATETIME

-- into the temporary table
INSERT INTO #ActiveEmployees ([EmployeeId])
SELECT [EMPLOYEE_NUMBER]
FROM [dbo].[EmployeeMaster]
WHERE [EMPLOYEE_NUMBER] IN (
        SELECT EmployeeId
        FROM [dbo].[EmployeeDetails]
        )

-- Get the number of records in the temporary table
SET @NumberRecords = @@ROWCOUNT
SET @RowCount = 1

-- loop through all records in the temporary table
-- using the WHILE loop construct
WHILE @RowCount <= @NumberRecords
BEGIN
 SELECT @EmployeeId = EmployeeId
 FROM #ActiveEmployees
 WHERE RowID = @RowCount

 SELECT @EmployeeName = EmployeeName FROM [dbo].[EmployeeDetails] WHERE [EmployeeId] = @EmployeeId
 IF(LTRIM(RTRIM(@EmployeeName)) <> (SELECT LTRIM(RTRIM([FIRST_NAME])) FROM [dbo].[EmployeeMaster] WHERE [EMPLOYEE_NUMBER] = @EmployeeId))
    BEGIN
        UPDATE [dbo].[EmployeeDetails] SET EmployeeName = (SELECT LTRIM(RTRIM([FIRST_NAME])) FROM [dbo].[EmployeeMaster] WHERE [EMPLOYEE_NUMBER] = @EmployeeId)
        WHERE EmployeeId = @EmployeeId
    END
 SELECT @EmployeeLastName = EmployeeLastName FROM [dbo].[EmployeeDetails] WHERE [EmployeeId] = @EmployeeId
 IF(LTRIM(RTRIM(@EmployeeLastName)) <> (SELECT LTRIM(RTRIM([LAST_NAME])) FROM [dbo].[EmployeeMaster] WHERE [EMPLOYEE_NUMBER] = @EmployeeId))
    BEGIN
        UPDATE [dbo].[EmployeeDetails] SET EmployeeLastName = (SELECT LTRIM(RTRIM([LAST_NAME])) FROM [dbo].[EmployeeMaster] WHERE [EMPLOYEE_NUMBER] = @EmployeeId)
        WHERE EmployeeId = @EmployeeId
    END
 SELECT @EmployeeCategory = [Category] FROM [dbo].[EmployeeCategory] WHERE [EmployeeCategoryId] = (SELECT [EmployeeCategoryId] FROM [dbo].[EmployeeDetails] WHERE [EmployeeId] = @EmployeeId)
 IF(LTRIM(RTRIM(@EmployeeCategory)) <> (SELECT LTRIM(RTRIM([JOB_NAME])) FROM [dbo].[EmployeeMaster] WHERE [EMPLOYEE_NUMBER] = @EmployeeId))
    BEGIN
        UPDATE [dbo].[EmployeeDetails] SET [EmployeeCategoryId] = (SELECT [EmployeeCategoryId] FROM [dbo].[EmployeeCategory] WHERE [Category] = (SELECT LTRIM(RTRIM([JOB_NAME])) FROM [dbo].[EmployeeMaster] WHERE [EMPLOYEE_NUMBER] = @EmployeeId)) 
        WHERE EmployeeId = @EmployeeId
    END
 SELECT @Email = Email FROM [dbo].[EmployeeDetails] WHERE [EmployeeId] = @EmployeeId
 IF(LTRIM(RTRIM(@Email)) <> (SELECT LTRIM(RTRIM([EMAIL_ADDRESS])) FROM [dbo].[EmployeeMaster] WHERE [EMPLOYEE_NUMBER] = @EmployeeId))
    BEGIN
        UPDATE [dbo].[EmployeeDetails] SET Email = (SELECT LTRIM(RTRIM([EMAIL_ADDRESS])) FROM [dbo].[EmployeeMaster] WHERE [EMPLOYEE_NUMBER] = @EmployeeId)
        WHERE EmployeeId = @EmployeeId
    END
 SELECT @Gender = Gender FROM [dbo].[EmployeeDetails] WHERE [EmployeeId] = @EmployeeId
 IF(LTRIM(RTRIM(@Gender)) <> (SELECT LTRIM(RTRIM([GENDER])) FROM [dbo].[EmployeeMaster] WHERE [EMPLOYEE_NUMBER] = @EmployeeId))
    BEGIN
        UPDATE [dbo].[EmployeeDetails] SET Gender = (SELECT LTRIM(RTRIM([GENDER])) FROM [dbo].[EmployeeMaster] WHERE [EMPLOYEE_NUMBER] = @EmployeeId)
        WHERE EmployeeId = @EmployeeId
    END
 SELECT @JoiningDate = JoiningDate FROM [dbo].[EmployeeDetails] WHERE [EmployeeId] = @EmployeeId
 IF(LTRIM(RTRIM(@JoiningDate)) <> (SELECT LTRIM(RTRIM([DATE_OF_JOINING])) FROM [dbo].[EmployeeMaster] WHERE [EMPLOYEE_NUMBER] = @EmployeeId))
    BEGIN
        UPDATE [dbo].[EmployeeDetails] SET JoiningDate = (SELECT LTRIM(RTRIM([DATE_OF_JOINING])) FROM [dbo].[EmployeeMaster] WHERE [EMPLOYEE_NUMBER] = @EmployeeId)
        WHERE EmployeeId = @EmployeeId
    END

 SET @RowCount = @RowCount + 1
END

-- drop the temporary table
DROP TABLE #ActiveEmployees

---

谢谢@marc_s

好吧，不用循环，而是在一条sql语句中完成它，然后用它来完成。真的

我看到了一个循环，看到了大量的独立语句，我可以想象这只是一个UPATE语句

---

在顶部，这不是“休表”。它很小。超小的。一百万行很小。这还不到27000行。你只是通过“程序员方法”——循环，太多的语句来滥用服务器。使用基于集合的方法，您的整个循环可以写成一条语句。

摆脱RBAR（一行一行）处理-关系数据库在数据集合中工作-使用单个基于集合的

语句，您就完成了

大致如下：

CREATE PROCEDURE usp_OracleSyncUpdate
AS
    CREATE TABLE #ActiveEmployees (
     RowID int IDENTITY(1, 1), 
     [EmployeeId] nvarchar(50),
    )

    -- into the temporary table
    INSERT INTO #ActiveEmployees ([EmployeeId])
      SELECT [EMPLOYEE_NUMBER]
      FROM [dbo].[EmployeeMaster]
      WHERE [EMPLOYEE_NUMBER] IN (SELECT EmployeeId
                              FROM [dbo].[EmployeeDetails])

    UPDATE dbo.EmployeeDetails
    SET ed.EmployeeName = LTRIM(RTRIM(ae.FIRST_NAME)),
        ed.EmployeeLastName = (SELECT LTRIM(RTRIM(ae.LAST_NAME)), 
            ed.EmployeeCategoryId = ec.EmployeeCategoryId,
            ed.Email = ae.Email,
            ed.Gender = ae.Gender,
            ed.JoiningDate = ae.JoiningDate
        FROM dbo.EmployeeDetails ed
        INNER JOIN #ActiveEmployees ae ON ed.EmployeeId = ae.EmployeeId
        INNER JOIN dbo.EmployeeCategory ec ON .......
        WHERE EmployeeId = @EmployeeId

我不知道

EmployeeCategory

表是如何链接到其他表的-您需要在那里的

内部联接

行中添加

JOIN

条件

---

另外，您也可以完全删除临时表，直接从

EmployeeMaster

更新

EmployeeDetails

，作为节省内存和处理时间的第二步。

请更改标题：更新超小表。甚至没有一百万行——这是很小的。优化的一种方法是避免RBAR（一行接一行）处理，而是使用基于集合的

UPDATE

语句……感谢您的快速响应。我将实施这一计划，并让所有人都知道结果。非常感谢。

CREATE PROCEDURE usp_OracleSyncUpdate
AS
    CREATE TABLE #ActiveEmployees (
     RowID int IDENTITY(1, 1), 
     [EmployeeId] nvarchar(50),
    )

    -- into the temporary table
    INSERT INTO #ActiveEmployees ([EmployeeId])
      SELECT [EMPLOYEE_NUMBER]
      FROM [dbo].[EmployeeMaster]
      WHERE [EMPLOYEE_NUMBER] IN (SELECT EmployeeId
                              FROM [dbo].[EmployeeDetails])

    UPDATE dbo.EmployeeDetails
    SET ed.EmployeeName = LTRIM(RTRIM(ae.FIRST_NAME)),
        ed.EmployeeLastName = (SELECT LTRIM(RTRIM(ae.LAST_NAME)), 
            ed.EmployeeCategoryId = ec.EmployeeCategoryId,
            ed.Email = ae.Email,
            ed.Gender = ae.Gender,
            ed.JoiningDate = ae.JoiningDate
        FROM dbo.EmployeeDetails ed
        INNER JOIN #ActiveEmployees ae ON ed.EmployeeId = ae.EmployeeId
        INNER JOIN dbo.EmployeeCategory ec ON .......
        WHERE EmployeeId = @EmployeeId