sqlserver top 异常

SQL语句：

 

String sql = "select top ? * from bbs_posts where p_fid=? order by p_addtime desc";
         prepStmt = conn.prepareStatement(sql);
         prepStmt.setInt(1, xxx);
         prepStmt.setInt(2, xx);
         prepStmt.executeQuery()

 

预编译：
Exception：

 

java.sql.SQLException: '@P0' 附近有语法错误。
     at net.sourceforge.jtds.jdbc.SQLDiagnostic.addDiagnostic(SQLDiagnostic.java:368)
     at net.sourceforge.jtds.jdbc.TdsCore.tdsErrorToken(TdsCore.java:2816)
     at net.sourceforge.jtds.jdbc.TdsCore.nextToken(TdsCore.java:2254)
     at net.sourceforge.jtds.jdbc.TdsCore.getMoreResults(TdsCore.java:631)
     at net.sourceforge.jtds.jdbc.JtdsStatement.executeSQLQuery(JtdsStatement.java:477)
     at net.sourceforge.jtds.jdbc.JtdsPreparedStatement.executeQuery(JtdsPreparedStatement.java:777)
     at yixun.wap.db.DBConnection.executeQuery(DBConnection.java:41)
     at yixun.wap.bbs.dao.ForumDAO.get500WANforum(ForumDAO.java:282)
     at yixun.wap.bbs.BbsCache.get500WANforumCache(BbsCache.java:91)
     at yixun.wap.bbs.service.ForumBO.get500WANforum(ForumBO.java:143)
     at _jsp._page._bbs._space._second__jsp._jspService(_second__jsp.java:83)

 

原因：sql不支持为select top ? 预编译，换成动态拼接

 

String sql = "select top %s * from bbs_posts where p_fid=? order by p_addtime desc";
         sql = String.format(sql, num);

 

    或者是：

String sql = "select top (?) * from bbs_posts where p_fid=? order by p_addtime desc";   
         prepStmt = conn.prepareStatement(sql);   
         prepStmt.setInt(1, xxx);   
         prepStmt.setInt(2, xx);   
         prepStmt.executeQuery()