FROM子句中的SQL语法错误

Question

下面是我遇到错误的代码：

FROM
    IndexPID
    INNER JOIN Demographics ON
        IndexPID.NDoc_Number = Demographics.NDoc_Number,
    PatientSupply
    INNER JOIN Demographics ON
        PatientSupply.NDocNum = Demographics.NDoc_Number

我也是这样尝试的：

FROM
    IndexPID, PatientSupply
    INNER JOIN Demographics ON
        IndexPID.NDoc_Number = Demographics.NDoc_Number
    INNER JOIN Demographics ON
        PatientSupply.NDocNum = Demographics.NDoc_Number

但是没有雪茄。有人告诉我我哪里做错了吗？

Answer 1

你们很接近了：

FROM IndexPID
INNER JOIN Demographics 
   ON IndexPID.NDoc_Number = Demographics.NDoc_Number
INNER JOIN PatientSupply
   ON Demographics.NDoc_Number = PatientSupply.NDocNum

Answer 2

如果你张贴整个SQL会更容易些！

试一试

FROM
IndexPID
INNER JOIN Demographics ON
    IndexPID.NDoc_Number = Demographics.NDoc_Number
INNER JOIN PatientSupply ON
    PatientSupply.NDocNum = Demographics.NDoc_Number

Answer 3

您在这里以一种奇怪的方式混合了隐式(逗号分隔)和显式JOIN。它应该如下所示，仅使用显式INNER JOIN，表名或ON子句之间不能有逗号：

FROM
  IndexPID
  INNER JOIN Demographics 
    ON IndexPID.Ndoc_Number = Demographics.NDoc_Number
  INNER JOIN PatientSupply 
    ON PatientSupply.NDocNum = Demographics.NDoc_Number