int i=0; while(i<=5) { ..... String sql="select * from menu where parent_id="+i; ResultSet rs1 = stmt1.executeQuery(sql); ..... i++; } 这样做的话会访问数据库6次 如果只是为了取得数据你可以这么写: String sql="select * from menu where parent_id between 0 and 5"; ResultSet rs1 = stmt1.executeQuery(sql);
我在下面还有个rs1.next()的循环,用你的方法,同样不能用
建议楼主能一次把问题准确的描述清楚。否则没有人会猜出你下面还有一个rs1.next()这样你直接用一楼提供的第二种方法String sql="select * from menu where parent_id between 0 and 5"; // or String sql="select * from menu where parent_id in (0,1,2,3,4,5)"; ResultSet rs1 = stmt1.executeQuery(sql); while (not rs1.eof) { }
while(i<=5)
{
.....
String sql="select * from menu where parent_id="+i;
ResultSet rs1 = stmt1.executeQuery(sql);
.....
i++;
}
这样做的话会访问数据库6次 如果只是为了取得数据你可以这么写:
String sql="select * from menu where parent_id between 0 and 5";
ResultSet rs1 = stmt1.executeQuery(sql);
建议楼主能一次把问题准确的描述清楚。否则没有人会猜出你下面还有一个rs1.next()这样你直接用一楼提供的第二种方法String sql="select * from menu where parent_id between 0 and 5";
// or String sql="select * from menu where parent_id in (0,1,2,3,4,5)";
ResultSet rs1 = stmt1.executeQuery(sql);
while (not rs1.eof)
{
}