Question

我在SQLite语法方面遇到了一些麻烦。

我能够让以下工作：

create table A as select * from DocumentFolders where DocumentFolders.folderId =202
create table B as select * from DocumentFolders where DocumentFolders.folderId =35 
create table C as select * from A join B on A.documentId = B.documentId

但我不能让这个复合语句起作用

select * from DocumentFolders where DocumentFolders.folderId =202 as A join select *
from DocumentFolders where DocumentFolders.folderId =35 as B on A.documentId =  
B.documentId

希望得到一些提示吗？

由于

标记

Answer 1

使用连接时，您仍然只有一个SELECT语句，它只能有一个FROM / WHERE子句：

SELECT *
FROM DocumentFolders AS A
JOIN DocumentFolders AS B USING (documentId)
WHERE A.folderId = 202
  AND B.folderId = 35

或者，您可以将完整的查询移动到子查询中：

SELECT *
FROM (SELECT * FROM DocumentFolders WHERE folderId = 202)
JOIN (SELECT * FROM DocumentFolders WHERE folderId = 35)  USING (documentId)

在SQLite 3.8.3或更高版本中，您可以使用公用表表达式：

WITH
A AS (SELECT * FROM DocumentFolders WHERE folderId = 202),
B AS (SELECT * FROM DocumentFolders WHERE folderId = 35)
SELECT *
FROM A
JOIN B USING (documentId)

SQLite内部联接

1 个答案: