gradesearch.cs

这是用SQL数据库做的学生信息管理系统。简明

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlClient;

namespace 学生与成绩
{
	/// <summary>
	/// GradeSearch 的摘要说明。
	/// </summary>
	public class GradeSearch : System.Windows.Forms.Form
	{
		private DataSet ds=new DataSet();
		private string sendStrSQL;
		private string sendTableName="成绩表";
		private DataTable myTable;
		private LinkDataBase link=new LinkDataBase();
		private System.Windows.Forms.Label label1;
		private System.Windows.Forms.Label label2;
		private System.Windows.Forms.ComboBox cobClass;
		private System.Windows.Forms.ComboBox cobCourse;
		private System.Windows.Forms.Button btnSearch;
		private System.Windows.Forms.DataGrid dataGrid1;
		/// <summary>
		/// 必需的设计器变量。
		/// </summary>
		private System.ComponentModel.Container components = null;

		public GradeSearch()
		{
			//
			// Windows 窗体设计器支持所必需的
			//
			InitializeComponent();

			//
			// TODO: 在 InitializeComponent 调用后添加任何构造函数代码
			//
		}

		/// <summary>
		/// 清理所有正在使用的资源。
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if(components != null)
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		#region Windows 窗体设计器生成的代码
		/// <summary>
		/// 设计器支持所需的方法 - 不要使用代码编辑器修改
		/// 此方法的内容。
		/// </summary>
		private void InitializeComponent()
		{
			this.label1 = new System.Windows.Forms.Label();
			this.label2 = new System.Windows.Forms.Label();
			this.cobClass = new System.Windows.Forms.ComboBox();
			this.cobCourse = new System.Windows.Forms.ComboBox();
			this.btnSearch = new System.Windows.Forms.Button();
			this.dataGrid1 = new System.Windows.Forms.DataGrid();
			((System.ComponentModel.ISupportInitialize)(this.dataGrid1)).BeginInit();
			this.SuspendLayout();
			// 
			// label1
			// 
			this.label1.Location = new System.Drawing.Point(35, 24);
			this.label1.Name = "label1";
			this.label1.TabIndex = 0;
			this.label1.Text = "选择班级";
			this.label1.TextAlign = System.Drawing.ContentAlignment.MiddleCenter;
			// 
			// label2
			// 
			this.label2.Location = new System.Drawing.Point(318, 24);
			this.label2.Name = "label2";
			this.label2.TabIndex = 1;
			this.label2.Text = "选择课程";
			this.label2.TextAlign = System.Drawing.ContentAlignment.MiddleCenter;
			// 
			// cobClass
			// 
			this.cobClass.Location = new System.Drawing.Point(166, 27);
			this.cobClass.Name = "cobClass";
			this.cobClass.Size = new System.Drawing.Size(121, 20);
			this.cobClass.TabIndex = 2;
			// 
			// cobCourse
			// 
			this.cobCourse.Location = new System.Drawing.Point(449, 27);
			this.cobCourse.Name = "cobCourse";
			this.cobCourse.Size = new System.Drawing.Size(121, 20);
			this.cobCourse.TabIndex = 3;
			// 
			// btnSearch
			// 
			this.btnSearch.Location = new System.Drawing.Point(601, 24);
			this.btnSearch.Name = "btnSearch";
			this.btnSearch.TabIndex = 4;
			this.btnSearch.Text = "查询";
			this.btnSearch.Click += new System.EventHandler(this.btnSearch_Click);
			// 
			// dataGrid1
			// 
			this.dataGrid1.DataMember = "";
			this.dataGrid1.HeaderForeColor = System.Drawing.SystemColors.ControlText;
			this.dataGrid1.Location = new System.Drawing.Point(20, 72);
			this.dataGrid1.Name = "dataGrid1";
			this.dataGrid1.ReadOnly = true;
			this.dataGrid1.Size = new System.Drawing.Size(672, 376);
			this.dataGrid1.TabIndex = 0;
			// 
			// GradeSearch
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
			this.ClientSize = new System.Drawing.Size(712, 466);
			this.Controls.Add(this.dataGrid1);
			this.Controls.Add(this.btnSearch);
			this.Controls.Add(this.cobCourse);
			this.Controls.Add(this.cobClass);
			this.Controls.Add(this.label2);
			this.Controls.Add(this.label1);
			this.Name = "GradeSearch";
			this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
			this.Text = "班级成绩查询";
			this.Load += new System.EventHandler(this.GradeSearch_Load);
			((System.ComponentModel.ISupportInitialize)(this.dataGrid1)).EndInit();
			this.ResumeLayout(false);

		}
		#endregion

		private void GradeSearch_Load(object sender, System.EventArgs e)
		{
			this.dataGrid1.CaptionText="班级成绩查询";
			myTable=new DataTable();
			myTable.Columns.Add("学号",typeof(char));
			myTable.Columns.Add("姓名",typeof(char));
			myTable.Columns.Add("成绩",typeof(char));
			this.dataGrid1.DataSource=myTable;
			//设置列表框下拉列表
			string StrConn="workstation id=localhost;Integrated Security=SSPI;database=stu01";
			SqlConnection conn=new SqlConnection(StrConn);
			conn.Open();
			SqlCommand cmd=conn.CreateCommand();
			cmd.CommandText="select 班级名称 from 班级";
			SqlDataReader dr=cmd.ExecuteReader();
			
			while(dr.Read())
			{
				this.cobClass.Items.Add(dr.GetValue(0).ToString().Trim());
			}
			this.GetCourse();
		}
		/*private void DataGridStateControl()
		{
			DataGridTableStyle ts=new DataGridTableStyle();
			ts.AlternatingBackColor=Color.Gray;
			ts.MappingName=ds.Tables[0].TableName;
			this.dataGrid1.TableStyles.Add(ts);
		}*/
		private void GetCourse()
		{
			string StrConn="workstation id=localhost;Integrated Security=SSPI;database=stu01";
			SqlConnection conn=new SqlConnection(StrConn);
			conn.Open();
			SqlCommand cmd=conn.CreateCommand();
			cmd.CommandText="select 名称 from 课程表";
			SqlDataReader dr=cmd.ExecuteReader();
			
			while(dr.Read())
			{
				this.cobCourse.Items.Add(dr.GetValue(0).ToString().Trim());
			}

		}

		private void btnSearch_Click(object sender, System.EventArgs e)
		{
			if(this.cobCourse.Text==""||this.cobClass.Text=="")
			{
				MessageBox.Show("查询条件不完整","信息",MessageBoxButtons.OK,MessageBoxIcon.Warning);
				return;
			}
			string classID=this.GetClassID();
			string courseID=this.GetCourseID();
			this.sendStrSQL="select STU.学号, STU.姓名, 成绩表.成绩 FROM STU INNER JOIN 班级 ON STU.班级编号 = 班级.班级编号 INNER JOIN 成绩表 ON STU.学号 = 成绩表.学号 AND 班级.班级编号 = 成绩表.班级编号 INNER JOIN 课程表 ON 成绩表.课程编号 = 课程表.编号"
				+" where (成绩表.班级编号='"+classID.Trim()+"') AND (成绩表.课程编号='"+courseID.Trim()+"')";
			this.ds=link.SelectDataBase(sendStrSQL,sendTableName);
			this.dataGrid1.DataSource=ds;
			this.dataGrid1.DataMember="成绩表";
			//this.DataGridStateControl();
		}
		//班级名称和班级编号的转换
		private string GetClassID()
		{
			string StrConn="workstation id=localhost;Integrated Security=SSPI;database=stu01";
			SqlConnection conn=new SqlConnection(StrConn);
			conn.Open();
			SqlCommand cmd=conn.CreateCommand();
			cmd.CommandText="select 班级编号 from 班级 where(班级名称='"+this.cobClass.Text.Trim()+"')";
			object classID=cmd.ExecuteScalar();
			return classID.ToString();
		}
		private string GetCourseID()
		{
			string StrConn="workstation id=localhost;Integrated Security=SSPI;database=stu01";
			SqlConnection conn=new SqlConnection(StrConn);
			conn.Open();
			SqlCommand cmd=conn.CreateCommand();
			cmd.CommandText="select 编号 from 课程表 where(名称='"+this.cobCourse.Text.Trim()+"')";
			object courseID=cmd.ExecuteScalar();
			return courseID.ToString();
		}
	}
}