sql - FROM 子句中的 SQL 语法错误

Question

这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

我也试过这样：

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。有人告诉我我做错了什么吗？

Answer 1

如果您发布整个 SQL 会更容易！

尝试

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

Answer 2

你非常接近：

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

Answer 3

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

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

Answer 4

您使用内部联接，因此您可以使用：

FROM Demographics
inner join IndexPID on Demographics.NDoc_Number=IndexPID.NDoc_Number
inner join PatientSupply on Demographics.NDoc_Number=PatientSupply.NDocNum