C#自选字段条件报表

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

using System.Data.SqlClient;

namespace FindOperator

{

    public partial class Frm_Main : Form

    {

        public Frm_Main()

        {

            InitializeComponent();

        }

        private void Frm_Main_Load(object sender, EventArgs e)

        {

            cbox_Field.DataSource = GetField("tb_student");//设置数据源

            cbox_Field.DisplayMember = "Name";//设置显示的属性

            dgv_Message.DataSource = GetMessage();//设置数据源

        }

        private void btn_Select_Click(object sender, EventArgs e)

        {

            dgv_Message.DataSource = GetStudent(SQLGenerator(//设置数据源

                "tb_Student", cbox_Field.Text, cbox_Operator.Text,

                txt_Condition.Text));

        }

        /// <summary>

        /// 查询数据表中字段信息

        /// </summary>

        /// <returns>方法返回DataTable对象</returns>

        private List<StudentField> GetField(string TableName)

        {

            string P_Str_ConnectionStr = string.Format(//创建数据库连接字符串

                @"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\DataBase\db_TomeTwo.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True");

            string P_Str_SqlStr = string.Format(//创建SQL查询字符串

                "select c.name from syscolumns c,sysobjects a where a.name='{0}' and a.id=c.id",

                TableName);

            SqlDataAdapter P_SqlDataAdapter = new SqlDataAdapter(//创建数据适配器

                P_Str_SqlStr, P_Str_ConnectionStr);

            DataTable P_dt = new DataTable();//创建数据表

            P_SqlDataAdapter.Fill(P_dt);//填充数据表

            List<StudentField> P_List_StudentField = new List<StudentField>();

            for (int i = 0; i < P_dt.Rows.Count; i++)

            {

                P_List_StudentField.Add(new StudentField()//向集合添加数据

                { Name = P_dt.Rows[i][0].ToString() });

            }

            return P_List_StudentField;//返回数据表

        }

        /// <summary>

        /// 动态生成SQL语句

        /// </summary>

        /// <param name="Table">表名</param>

        /// <param name="Field">字段名</param>

        /// <param name="Operator">操作符</param>

        /// <param name="Condition">条件</param>

        /// <returns>方法返回SQL语句</returns>

        private string SQLGenerator(string Table,string Field,string Operator,string Condition)

        {

            string P_Str = "SELECT * FROM "+Table;//生成SQL语句

            switch (Operator)

            {

                case "%Like%":

                    P_Str += string.Format(" WHERE {0} Like '%{1}%'",Field,Condition);//添加字符串

                    break;

                case "Like%":

                    P_Str += string.Format(" WHERE {0} Like '{1}%'", Field, Condition);//添加字符串

                    break;

                case "%Like":

                    P_Str += string.Format(" WHERE {0} Like '%{1}'", Field, Condition);//添加字符串

                    break;

                default:

                    if (Condition==string.Empty)

                    {

                        P_Str += string.Format(" WHERE {0} IS null OR {0}=''", Field);//添加字符串

                        break;

                    }

                    P_Str += string.Format(" WHERE {0} {1} '{2}'",//添加字符串

                        Field, Operator, Condition);

                    break;

            }

            return P_Str;//方法返回字符串对象

        }

        /// <summary>

        /// 根据指定SQL语句查询数据库信息

        /// </summary>

        /// <returns>方法返回DataTable对象</returns>

        private DataTable GetStudent(string SQL)

        {

            string P_Str_ConnectionStr = string.Format(//创建数据库连接字符串

                @"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\DataBase\db_TomeTwo.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True");

            SqlDataAdapter P_SqlDataAdapter = new SqlDataAdapter(//创建数据适配器

                SQL, P_Str_ConnectionStr);

            DataTable P_dt = new DataTable();//创建数据表

            P_SqlDataAdapter.Fill(P_dt);//填充数据表

            return P_dt;//返回数据表

        }

        /// <summary>

        /// 查询数据库信息

        /// </summary>

        /// <returns>方法返回DataTable对象</returns>

        private DataTable GetMessage()

        {

            string P_Str_ConnectionStr = string.Format(//创建数据库连接字符串

                @"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\DataBase\db_TomeTwo.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True");

            string P_Str_SqlStr = string.Format(//创建SQL查询字符串

                "SELECT * FROM tb_Student");

            SqlDataAdapter P_SqlDataAdapter = new SqlDataAdapter(//创建数据适配器

                P_Str_SqlStr, P_Str_ConnectionStr);

            DataTable P_dt = new DataTable();//创建数据表

            P_SqlDataAdapter.Fill(P_dt);//填充数据表

            return P_dt;//返回数据表

        }

    }

    class StudentField

    {

        public string Name { get; set; }//定义属性

        public override string ToString()//重写ToString方法

        {

            return Name.ToString();

        }

    }

}