检查存储过程：转换时区的特定城市的日期时间到另一个

Question

我试图创建存储过程谁时区的特定城市的日期时间转换为另一种使用这篇文章：Effectively Converting dates between UTC and Local (ie. PST) time in SQL 2005

ALTER PROCEDURE [dbo].[Get_TimeOfTimeZone] 
    (
     @DateTimeFrom datetime, 
     @CityNameFrom nvarchar(MAX), 
     @CityNameTo  nvarchar(MAX), 
     @ResultDate  datetime OUTPUT 
    ) 

AS 
    SET NOCOUNT ON 

    SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED 

    Declare @Query nvarchar(1000) 
    Declare @ParmDefinition nvarchar (500) 

    SET @Query = N'' 
    SET @Query = @Query + N'SELECT tz.Offset, tz.TimeZoneID ' 
    SET @Query = @Query + N'FROM TimeZoneCity, TimeZones tz WITH (NOLOCK) ' 
    --SET @Query = @Query + N'INNER JOIN TimeZones WITH (NOLOCK) ON TimeZoneCity.TimeZoneID = tz.TimeZoneID ' 
    SET @Query = @Query + N'LEFT JOIN TimeZoneDaylightSavings WITH (NOLOCK) ON TimeZoneDaylightSavings.TimeZoneID = tz.TimeZoneID ' 
    SET @Query = @Query + N' WHERE TimeZoneCity.CityName = @CityNameTo ' 
    SET @Query = @Query + N' AND TimeZoneCity.TimeZoneID = tz.TimeZoneID ' 
    SET @Query = @Query + N'  AND @DateTimeFrom >= TimeZoneDaylightSavings.BeginDst AND @DateTimeFrom < TimeZoneDaylightSavings.EndDst ' 

    SET @Query = @Query + N'SET @ResultDate = DATEADD(HH, tz.Offset + CASE WHEN tz.TimeZoneID IS NOT NULL THEN 1 ELSE 0 END, ' 
    SET @Query = @Query + N'       DATEADD(HH, (SELECT TimeZones.Offset ' 
    SET @Query = @Query + N'           FROM TimeZones, TimeZoneCity WITH (NOLOCK) ' 
    SET @Query = @Query + N'           WHERE TimeZoneCity.CityName = @CityNameFrom ' 
    SET @Query = @Query + N'           AND TimeZoneCity.TimeZoneID = TimeZones.TimeZoneID), ' 
    SET @Query = @Query + N'         @DateTimeFrom)) ' 

    SET @ParmDefinition = N'@ResultDate datetime, @DateTimeFrom datetime, @CityNameFrom nvarchar(MAX), @CityNameTo nvarchar(MAX) ' 

    EXECUTE sp_executesql @Query, @ParmDefinition, @ResultDate = @ResultDate, @DateTimeFrom = @DateTimeFrom, @CityNameFrom = @CityNameFrom, @CityNameTo = @CityNameTo 

    SET NOCOUNT OFF 
RETURN 

当我执行它，我有这些错误：

Msg 4104, Level 16, State 1, Line 1 
The multi-part identifier "tz.Offset" could not be bound. 
Msg 4104, Level 16, State 1, Line 1 
The multi-part identifier "tz.TimeZoneID" could not be bound. 

任何人可以检查我的存储过程，并帮助我吗？非常感谢

Answer 1

您在查询中混合了JOIN类型。下面一行用逗号连接和WHERE条款

FROM TimeZoneCity, TimeZones tz WITH (NOLOCK) 

因为你是混合联接语法，别名tz不可用。你应该始终使用相同的语法。这条线应该是：

SET @Query = @Query + N'FROM TimeZoneCity 
         INNER JOIN TimeZones tz WITH (NOLOCK) 
           ON TimeZoneCity.TimeZoneID = tz.TimeZoneID'