SQL 卡住，否则语法错误答案

【问题标题】：SQL stuck on and else syntax errorSQL 卡住，否则语法错误
【发布时间】：2018-08-28 13:23:41
【问题描述】：

我遇到了一个 ELSE 语法错误，非常感谢第二双眼睛告诉我哪里出了问题！我正在使用 SSMS v17.3。我收到的消息是：

消息 156，级别 15，状态 1，第 98 行

关键字“ELSE”附近的语法不正确。

第 98 行是 go 之前的最后一个 ELSE。在整个语句的结尾上方大约 6 行。提前谢谢你！

DECLARE @GroupID uniqueidentifier
DECLARE @fCompID int
DECLARE @fPropID int
DECLARE @fCompGUID uniqueidentifier

Set @GroupID = 'E63DC5E7-C8C8-4EA3-B1BF-75712DD83EF4'
SET @fCompID = '0'
SET @fPropID = '0'

WHILE @fCompID <= '999'
    BEGIN
    IF @fCompID = (SELECT fID FROM tSCCompany WHERE fID = @fCompID)
        SET @fCompGUID = (SELECT fCompanyID FROM tSCCompany WHERE fID = @fCompID)
        WHILE @fPropID <='999'
            BEGIN
            IF @fPropID = (SELECT fID FROM tSCProperty WHERE fID = @fPropID AND fCompanyID = @fCompGUID)
                BEGIN
                INSERT INTO zPropTest(fGroupID, fPropertyID)
                    Select @GroupID, (select fPropertyID from tSCProperty where fID = @fPropID AND fCompanyID = @fCompGUID)
                SET @fPropID = @fPropID + 1
                END
            ELSE
                BEGIN
                SET @fPropID = @fPropID + 1
                END
            END
    ELSE
        BEGIN
        SET @fCompID = @fCompID + 1
        SET @fPropID = '0'
        END
    END
GO

【问题讨论】：

您忘记使用 BEGIN AND END 指示第一个 if 块。尝试在 SET @fCompGUID = (SELECT fCompanyID FROM tSCCompany WHERE fID = @fCompID) 之前写 BEGIN 并在结尾 while 之后写 END
旁白：看起来您已经学习了一门过程语言，并且正在将这些课程应用于 SQL。 SQL 最适合用于处理数据集并允许数据库优化实际处理，例如使用insert into zPropTest ( fGroupId, fPropertyId ) select @GroupId, tSCPropertyId from tSCProperty where fCompanyId = @fCompGUID where fPropertyId <= 999;。您还在混合数据类型，例如@fCompId < '999' 根据data type precedence 的规则将int 与字符串进行比较。

标签： tsql if-statement while-loop sql-server-2012

【解决方案1】：

我认为你错过了 TOP 1

DECLARE @GroupID uniqueidentifier
DECLARE @fCompID int
DECLARE @fPropID int
DECLARE @fCompGUID uniqueidentifier

Set @GroupID = 'E63DC5E7-C8C8-4EA3-B1BF-75712DD83EF4'
SET @fCompID = '0'
SET @fPropID = '0'

WHILE @fCompID <= '999'
    BEGIN
        IF @fCompID = (SELECT fID FROM tSCCompany WHERE fID = @fCompID) -- Need top 1?
            SET @fCompGUID = (SELECT fCompanyID FROM tSCCompany WHERE fID = @fCompID) -- Need top 1?
            WHILE @fPropID <='999'
                BEGIN
                    IF @fPropID = (SELECT fID FROM tSCProperty WHERE fID = @fPropID AND fCompanyID = @fCompGUID) -- Need top 1?
                        BEGIN
                            INSERT INTO zPropTest(fGroupID, fPropertyID)
                                Select @GroupID, 
                                    (select top 1 fPropertyID from tSCProperty 
                                        where fID = @fPropID AND fCompanyID = @fCompGUID)
                            SET @fPropID = @fPropID + 1
                        END
                    ELSE
                        BEGIN
                            SET @fPropID = @fPropID + 1
                        END
                END
        ELSE
            BEGIN
                SET @fCompID = @fCompID + 1
                SET @fPropID = '0'
            END
    END
GO

【讨论】：

【解决方案2】：

您似乎缺少一个开始块。请尝试如下：

DECLARE @GroupID uniqueidentifier
DECLARE @fCompID int
DECLARE @fPropID int
DECLARE @fCompGUID uniqueidentifier

Set @GroupID = 'E63DC5E7-C8C8-4EA3-B1BF-75712DD83EF4'
SET @fCompID = '0'
SET @fPropID = '0'
BEGIN-- MISSING!!
WHILE @fCompID <= '999'
    BEGIN
    IF @fCompID = (SELECT fID FROM tSCCompany WHERE fID = @fCompID)

        SET @fCompGUID = (SELECT fCompanyID FROM tSCCompany WHERE fID = @fCompID)
        WHILE @fPropID <='999'
            BEGIN
            IF @fPropID = (SELECT fID FROM tSCProperty WHERE fID = @fPropID AND fCompanyID = @fCompGUID)
                BEGIN
                INSERT INTO zPropTest(fGroupID, fPropertyID)
                    Select @GroupID, (select fPropertyID from tSCProperty where fID = @fPropID AND fCompanyID = @fCompGUID)
                SET @fPropID = @fPropID + 1
                END
            ELSE
                BEGIN
                SET @fPropID = @fPropID + 1
                END
            END
      END-- MISSING
    ELSE
        BEGIN
        SET @fCompID = @fCompID + 1
        SET @fPropID = '0'
        END
    END
GO

【讨论】：

【解决方案3】：

欢迎来到 Stack Overflow！

您的If 语句需要块指示符。查看我添加的两行

DECLARE @GroupID uniqueidentifier
DECLARE @fCompID int
DECLARE @fPropID int
DECLARE @fCompGUID uniqueidentifier

Set @GroupID = 'E63DC5E7-C8C8-4EA3-B1BF-75712DD83EF4'
SET @fCompID = '0'
SET @fPropID = '0'

WHILE @fCompID <= '999'
    BEGIN
    IF @fCompID = (SELECT fID FROM tSCCompany WHERE fID = @fCompID)
        Begin  --  I added this
            SET @fCompGUID = (SELECT fCompanyID FROM tSCCompany WHERE fID = @fCompID)
            WHILE @fPropID <='999'
                BEGIN
                IF @fPropID = (SELECT fID FROM tSCProperty WHERE fID = @fPropID AND fCompanyID = @fCompGUID)
                    BEGIN
                    INSERT INTO zPropTest(fGroupID, fPropertyID)
                        Select @GroupID, (select fPropertyID from tSCProperty where fID = @fPropID AND fCompanyID = @fCompGUID)
                    SET @fPropID = @fPropID + 1
                    END
                ELSE
                    BEGIN
                    SET @fPropID = @fPropID + 1
                    END
                End
        End  --  I added this, too 
    ELSE
        BEGIN
        SET @fCompID = @fCompID + 1
        SET @fPropID = '0'
        END
    END
GO

【讨论】：