当我尝试做下面的编码时,我得到和错误。我无法理解这个netbeans错误。错误如下:
Mar 21, 2013 2:28:19 AM timetable.generator.JFTTGenerator6 jButton2ActionPerformed
SEVERE: null
java.sql.SQLException: Before start of result set
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1073)
请帮帮我!!!!
String subj=(String) jTable1.getValueAt(0,1 );
Connection con = Driver.connect();
ResultSet lec1=Handler.getData(con,
"select lec_id from lecdetails,subjects where subjects.sub_code=lecdetails.sub_code
and subjects.sub_name='"+subj+"'");
ResultSet rst1= Handler.getData(con, "select sub_name from subjects,lecdetails
where subjects.sub_code=lecdetails.sub_code and subjects.sem='2nd' and
lecdetails.lec_id <> '"+lec1.getString(1) +"' order by rand() limit 1 ");
jTable2.setValueAt(lec1.getString(1), 0, 1);
在使用lec.getString(1)
之前,您必须调用next()
。
那么,在语句之前ResultSet rst1= Handler.getData
,
if (lec1.next()){
//second result set statement.
//set value in jtable
}