小编Aka*_*glo的帖子

我有以下代码验证从SQL Server检索到的用户ID和密码，但是我希望密码的验证区分大小写。

    Dim frm As New MarksEntryFrm
    Dim flag As Boolean
    flag = False
    cmd = New SqlCommand("Select a.Form,a.AcademicYear,b.SubjectID,b.UserID,b.Password,c.Term from StudentDetails.Programmes a, StudentDetails.Subjects b,RegistrationDetails.Registration c where b.SubjectID='" & cboSubjCode.SelectedItem & "' and b.UserID='" & txtUserName.Text & "' and b.Password='" & txtPassword.Text & "'", cn)
    dr1 = cmd.ExecuteReader
    ctr = ctr + 1
    If dr1.Read Then
        frm.Show()
        ctr = 0
        Me.Hide()
    ElseIf ctr < 3 Then
        MessageBox.Show("Incorrect Subject Code,User Name or Password. Please try again.", "Wrong data entered", MessageBoxButtons.OK, MessageBoxIcon.Asterisk)
    Else …

给定a = 1,b = 5和c = 6的值,x的值应该是-2和-3,但是下面的程序给出x的值为6和-11,这是不正确的.如果有人能弄清楚该计划有什么问题,我将不胜感激.

#include<iostream.h>
#include<conio.h>

int main()
{
    char reply;
    int a,b,c,q,z;

    do
    {
        cout<<"Enter the value of a: ";
        cin>>a;
        cout<<"\nEnter the value of b: ";
        cin>>b;
        cout<<"\nEnter the value of c: ";
        cin>>c;

       q=(-b-(b*b-4*a*c)sqrt(b))/2/a;

       z=(-b+(b*b-4*a*c)sqrt(b))/2/a;

        cout<<"\nThe values of x are "<<q<<" and "<<z;
        cout<<"\nDo you want to find another values of x(y/n)?";
        cin>>reply;
    }
    while(reply=='y');

    getch();
    return 0;
}