求助 代码有错
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'where book.bookclass=bookclass.Id order by book.Id desc limit 0, 10' at line 1
sqlStr="select book.id,book.bookname,book.bookclass,bookclass.classname,"+
"book.author,book.publish,book.bookno,book.content,book.prince,book.amount,"+
"book.Leav_number,book.regtime,book.picturefrombook ,bookclass "+
"where book.bookclass=bookclass.Id";
if(!classid.equals("")&&keyword.equals("")){
if(page==1)
{
sqlStr=sqlStr+"andbook.bookclass='"+classid+"'"+
"orderbybook.Iddesc";
}else{
sqlStr=sqlStr+"andbook.bookclass='"+classid+"limit"+
(recordCount-pageSize*page)+","+(recordCount-pageSize*(page-
1));
}
}else if(!keyword.equals("")){
if(page==1){
if(!classid.equals("")){
sqlStr=sqlStr+"andbook.Bookclass='"+
classid+"'and(upper(book.bookname)like'%"+
keyword+"%'orupper(book.content)like'%"+
keyword+"%') orderbybook.Iddesc";
}else{
sqlStr=sqlStr+"and(upper(book.bookname)like'%"+
keyword+"%'orupper(book.content)like'%"+
keyword+"%')orderbybook.Iddesc";
}
}else{
if(!classid.equals("")){
sqlStr=sqlStr+"andbook.Bookclass='"+
classid+"'and(upper(book.bookname)like'%"+
keyword+"%'orupper(book.content)like'%"+
keyword+"%')limit"+(recordCount-pageSize*page)+","+
(recordCount-pageSize*(page-1));
}else{
sqlStr=sqlStr+"and(upper(book.bookname)like'%"+
keyword+"%'orupper(book.content)like'%"+
keyword+"%')limit"+(recordCount-pageSize*page)+","+
(recordCount-pageSize*(page-1));
}
}
}else{
if(page==1){
// sqlStr=sqlStr+" order by book.id desc limit 0,"+pageSize;
// sqlStr=sqlStr+" order by Id desc "+pageSize;
sqlStr=sqlStr+" order by book.Id desc limit 0, "+pageSize;
}else{
sqlStr=sqlStr+"limit"+(recordCount-pageSize*page)+","+
(recordCount-pageSize*(page-1));
}
}
try {
rs=stmt.executeQuery(sqlStr);
booklist=new Vector(rscount);
。。。。。。。。。。。。。。。。。。
。。。。。。。。。。。。。。。。。。。。。。。。。。 }
rs.close();
return true;
}catch(Exception e){
System.out.println(e.getMessage());
return false;
}
}
public boolean insert() throws Exception{
。。。。。。。。。。。。。。。。。。。。。。。。。
。。。。。。。。。。。。。。。。。。。。
}
}
public boolean delete(int aid) throws Exception{
sqlStr="delete from book where id=" +aid;
try
{ DataBase db=new DataBase();
db.connect();
stmt=db.conn.createStatement();
stmt.execute(sqlStr);
return true;
}
catch(SQLException e)
{
System.out.println(e);
return false;
}
}
public boolean getOnebook(int newid) throws Exception{
DataBase db=new DataBase();
db.connect();
stmt=db.conn.createStatement();
try{
sqlStr="select book.id,book.bookname,book.bookclass,bookclass.classname,book.author,"+
"book.publish,book.bookno,book.content,book.prince,book.amount,book.Leav_number,"+
"book.regtime,book.picturefrombook ,bookclass where book.Bookclass="+
"bookclass.Id and book.Id="+newid;
rs=stmt.executeQuery(sqlStr);
if(rs.next())
{ booklist=new Vector(1);
book book=new book();
book.setId(rs.getLong("id"));
book.setBookName(rs.getString("bookname"));
book.setBookClass(rs.getInt("bookclass"));
book.setClassname(rs.getString("classname"));
book.setAuthor(rs.getString("author"));
book.setPublish(rs.getString("publish"));
book.setBookNo(rs.getString("Bookno"));
book.setContent(rs.getString("content"));
book.setPrince(rs.getFloat("prince"));
book.setAmount(rs.getInt("amount"));
book.setLeav_number(rs.getInt("leav_number"));
book.setRegTime(rs.getString("regtime"));
book.setPicture(rs.getString("picture"));
booklist.addElement(book);
}else{
rs.close();
return false;
}
rs.close();
return true;
}
catch(SQLException e)
{
return false;
}
}
}
[解决办法]
sqlStr="select book.id,book.bookname,book.bookclass,bookclass.classname,"+
"book.author,book.publish,book.bookno,book.content,book.prince,book.amount,"+
"book.Leav_number,book.regtime,book.picturefrombook ,bookclass "+
"where book.bookclass=bookclass.Id";这个SQL语句有错 怎么没有看到from这个关键字 你要从哪张表里面查数据啊就要加上from哪张表
