我还是新手,这是我第一次使用这些多表查询。为什么我会出现这样的错误?这是我的代码:
String selectQuery =
" select *" +
" from tableassign left outer join\n" +
" tableacc\n" +
" on tableassign.signeeid = tableacc.userid left outer join\n" +
" tableinfo\n" +
" on tableassign.signeeid = tableinfo.userid left outer join\n" +
" WHERE tableassign.signeedepid =?";
Cursor data = db.rawQuery(selectQuery , new String[]{ signeedep });
错误:
android.database.sqlite.SQLiteException: near "WHERE": syntax error (code 1):
, while compiling: select * from tableassign left outer join tableacc on
tableassign.signeeid = tableacc.userid left outer join tableinfo on
tableassign.signeeid = tableinfo.userid left outer join WHERE
tableassign.signeedepid =?
看来你有一个复制/粘贴问题。删除left outer join
之前的最后一个where
:
String selectQuery =
" select *" +
" from tableassign left outer join\n" +
" tableacc\n" +
" on tableassign.signeeid = tableacc.userid left outer join\n" +
" tableinfo\n" +
" on tableassign.signeeid = tableinfo.userid\n" +
" WHERE tableassign.signeedepid =?";
Cursor data = db.rawQuery(selectQuery , new String[]{ signeedep });
我的格式有点不同,主要是为了便于阅读:
String selectQuery =
" SELECT *\n" +
" FROM tableassign\n" +
" LEFT JOIN tableacc ON tableassign.signeeid = tableacc.userid\n" +
" LEFT JOIN tableinfo ON tableassign.signeeid = tableinfo.userid\n" +
" WHERE tableassign.signeedepid =?";
Cursor data = db.rawQuery(selectQuery , new String[]{ signeedep });
虽然我不确定您正在使用哪种结构化语言进行查询,但问题似乎在于您使用JOIN运算符。有关LEFT OUTER JOIN的Oracle文档显示了它的正确用法,其语法为:
TableExpression LEFT [ OUTER ] JOIN TableExpression
{
ON booleanExpression |
USING clause
}
最后的LEFT OUTER JOIN紧接在WHERE子句之前,而没有定义TableExpression。删除LEFT OUTER JOIN子句以删除错误。
String selectQuery =
" select *" +
" from tableassign left outer join\n" +
" tableacc\n" +
" on tableassign.signeeid = tableacc.userid left outer join\n" +
" tableinfo\n" +
" on tableassign.signeeid = tableinfo.userid" +
" WHERE tableassign.signeedepid =?";
Cursor data = db.rawQuery(selectQuery , new String[]{ signeedep });