今天做項目的時候遇到這樣一個問題:
項目中執行sql語句,報錯,說是沒有M.id這個列。
sql語句:
select distinct M.[id],M.[book_id],M.[mark_title],M.[mark_content],M.[type],M.[chapter_id],M.[chapter_filename],M.[filename],M.[create_time],M.[param1],M.[param2],M.[numchapter],M.[flag],M.[extra],N.[numchapter]from(select A.[id],A.[book_id],A.[mark_title],A.[mark_content],A.[type],A.[chapter_id],A.[chapter_filename],A.[filename],A.[create_time],B.[param1],B.[param2],A.[numchapter],A.[flag],A.[extra]from book_new_mark A left join book_mark_rowindex Bon (A.[book_id] = B.[book_id] or A.[filename] = B.[book_id]) and A.[type] = B.[type]and (A.[extra] = B.[account] or ((A.[extra] is null or A.[extra] = '')and(B.[account] is null or B.[account] = ''))) order by A.[create_time],A.[id] asc) M left join book_case N on M.[book_id] = N.[bookid]
但是我在SQLite工具上測試sql可用,而且應用上也有類似的語句成功運行。
我折騰了半天,最後改成這樣:
select distinct M.id,M.book_id,M.mark_title,M.mark_content,M.type,M.chapter_id,M.chapter_filename,M.filename,M.create_time,M.param1,M.param2, M.numchapter,M.flag,M.extra,N.numchapter from(select *from book_new_mark A left join book_mark_rowindex Bon (A.book_id = B.book_id or A.filename = B.book_id)and A.type = B.type and (A.extra = B.account or ((A.extra is null or A.extra = '')and(B.account is null or B.account = ''))) order by A.create_time,A.id asc) M left join book_case Non M.book_id = N.bookid
這樣就可以了,我懷疑是因為長度問題,但是搜了一下沒有說明,執行sql方法的API也沒有說明。求大拿說明?