更新查询，MS Access：查询表达式中的语法错误（缺少运算符）

Question

Simple straightforward example: I have two similar tables containing Key and Val fields.简单直接的示例：我有两个相似的表，其中包含Key和Val字段。

Then I try to update one table with the values from the other:然后我尝试用另一个表的值更新一个表：

docmd.RunSQL "UPDATE [t-dest] SET [t-dest].val = [t-source].val " & _
   " FROM [t-source] WHERE [t-source].key = [t-dest].key"

and receive this Syntax Error message:并收到此语法错误消息：

Syntax error (missing operator) in query expression 
'[t-source].val FROM [t-source]'

Please help to find the cause of this error!请帮忙找出这个错误的原因！

Answer 1

DoCmd.RunSQL "UPDATE [t-dest] INNER JOIN [t-source] " & _
    "ON [t-source].key = [t-dest].key " & _
    "SET [t-dest].val = [t-source].val"