尝试使用内部联接进行更新查询，并使集合反映当前月数。
需要语法帮助来更新包含月份列的联接表，需要更新月份（date（））+1，+2。尝试使用下面嵌套的iif作为“iif（month（date（））=”1”，（set table.c=table2.c2……）完成下面的代码。
结果是语法错误
使用用于更新的值更新sql tablelinked excel的示例数据

Update dbo_MasterSalesForecast_Test

INNER JOIN MasterSalesForecastUpdate

ON (dbo_MasterSalesForecast_Test.SubTo=MasterSalesForecastUpdate.Item) AND( dbo_MasterSalesForecast_Test.Planner=MasterSalesForecastUpdate.Planner)

IIF(Month(Date()) ="1",( SET

dbo_MasterSalesForecast_Test.[YY:1] = [MasterSalesForecastUpdate].[YYJan],

dbo_MasterSalesForecast_Test.[YY:2] = [MasterSalesForecastUpdate].[YYFan],

dbo_MasterSalesForecast_Test.[YY:3] = [MasterSalesForecastUpdate].[YYMar])

,

IIF(Month(Date())="2",( SET

dbo_MasterSalesForecast_Test.[YY:2]=[MasterSalesForecastUpdate].[YYFeb],

dbo_MasterSalesForecast_Test.[YY:3]=[MasterSalesForecastUpdate].[YYMar],

dbo_MasterSalesForecast_Test.[YY:4]=[MasterSalesForecastUpdate].[YYApr])

,

IIF(Month(Date())="3",( SET

dbo_MasterSalesForecast_Test.[YY:3]=[MasterSalesForecastUpdate].[YYMar],

dbo_MasterSalesForecast_Test.[YY:4]=[MasterSalesForecastUpdate].[YYApr],

dbo_MasterSalesForecast_Test.[YY:5]=[MasterSalesForecastUpdate].[YYMay])

,

IIF(Month(Date())="4",(SET

dbo_MasterSalesForecast_Test.[YY:4]=[MasterSalesForecastUpdate].[YYApr],

dbo_MasterSalesForecast_Test.[YY:5]=[MasterSalesForecastUpdate].[YYMay],

dbo_MasterSalesForecast_Test.[YY:6]=[MasterSalesForecastUpdate].[YYJun])

,

IIF(Month(Date())="5",(SET

dbo_MasterSalesForecast_Test.[YY:5]=[MasterSalesForecastUpdate].[YYMay],

dbo_MasterSalesForecast_Test.[YY:6]=[MasterSalesForecastUpdate].[YYJun],

dbo_MasterSalesForecast_Test.[YY:7]=[MasterSalesForecastUpdate].[YYJul])

,

IIF(Month(Date())="6",(SET

dbo_MasterSalesForecast_Test.[YY:6]=[MasterSalesForecastUpdate].[YYJun],

dbo_MasterSalesForecast_Test.[YY:7]=[MasterSalesForecastUpdate].[YYJul],

dbo_MasterSalesForecast_Test.[YY:8]=[MasterSalesForecastUpdate].[YYAug])

,

IIF(Month(Date())="7",(SET

dbo_MasterSalesForecast_Test.[YY:7]=[MasterSalesForecastUpdate].[YYJul],

dbo_MasterSalesForecast_Test.[YY:8]=[MasterSalesForecastUpdate].[YYAug],

dbo_MasterSalesForecast_Test.[YY:9]=[MasterSalesForecastUpdate].[YYSep])

,

IIF(Month(Date())="8",(SET

dbo_MasterSalesForecast_Test.[YY:8]=[MasterSalesForecastUpdate].[YYAug],

dbo_MasterSalesForecast_Test.[YY:9]=[MasterSalesForecastUpdate].[YYSep],

dbo_MasterSalesForecast_Test.[YY:10]=[MasterSalesForecastUpdate].[YYOct])

,

IIF(Month(Date())="9",(SET

dbo_MasterSalesForecast_Test.[YY:9]=[MasterSalesForecastUpdate].[YYSep],

dbo_MasterSalesForecast_Test.[YY:10]=[MasterSalesForecastUpdate].[YYOct],

dbo_MasterSalesForecast_Test.[YY:11]=[MasterSalesForecastUpdate].[YYNov])

,

IIF(Month(Date())="10",(SET

dbo_MasterSalesForecast_Test.[YY:10]=[MasterSalesForecastUpdate].[YYOct],

dbo_MasterSalesForecast_Test.[YY:11]=[MasterSalesForecastUpdate].[YYNov],

dbo_MasterSalesForecast_Test.[YY:12]=[MasterSalesForecastUpdate].[YYDec])

,

IIF(Month(Date())="11",(SET

dbo_MasterSalesForecast_Test.[YY:11]=[MasterSalesForecastUpdate].[YYNov],

dbo_MasterSalesForecast_Test.[YY:12]=[MasterSalesForecastUpdate].[YYDec],

dbo_MasterSalesForecast_Test.[YY+1:1]=[MasterSalesForecastUpdate].[YY+1Jan])

,

IIF(Month(Date())="12"(SET

dbo_MasterSalesForecast_Test.[YY:12]=[MasterSalesForecastUpdate].[YYDec],

dbo_MasterSalesForecast_Test.[YY+1:1]=[MasterSalesForecastUpdate].[YY+1Jan],

dbo_MasterSalesForecast_Test.[YY+1:02]=[MasterSalesForecastUpdate].[YY+1Feb])

)))))))))));