错误：缺少Table的From-Clause条目

Question

我无法在postgresql中找到答案：

SELECT Week1.Material, Week1.VALa, Week1.MVGavgprice, concat(Week1.Material, Week1.VALa)

FROM "Week1"

错误：

  

缺少FROM-clause条目表＃34;第1周和第34天;   第1行：选择Week1.Material，Week1.VALa，Week1.MVGavgprice，concat ...                  ^   SQL状态：42P01   性格：8