这段程序错哪了

Question

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;namespace WindowsApplication3
{
    public partial class Form1 : Form
    {
        public string Str;
        public Form1()
        {
            InitializeComponent();
        }        private void button1_Click(object sender, EventArgs e)
        {
            int length = 1;
            int count = 1;
            while(count>0)
            {
            Str = textBox1.Text.ToString();
            string Str1 = Str.Substring(0, length);
            string strConnection = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=e:/Dict.mdb;User ID=admin;Password=;Jet OLEDB:Database Password=123456";
            OleDbConnection objConnection = new OleDbConnection(strConnection);
            objConnection.Open();
            string StrCon = "select count(*) from dict where Han like '" + Str1 + "%'";
            OleDbCommand objCommand = new OleDbCommand(StrCon, objConnection);
            count = Convert.ToInt32(objCommand.ExecuteScalar());
            length = length + 1;
            if (length > Str.Length)
            {
                listBox1.Items.Add(Str1);
                break;
            }
            else
            {
                string Strsy = Str.Substring(Str1.ToString().Length, Str.ToString().Length);
                listBox2.Items.Add(Strsy);
            }            }
            
        }
    }
}我的这段程序的目的是在数据库里查询textbox控件里的字符串（比如输入的字符串是“给国家和社会造成巨大损失”，我的程序就是要先查第一个字“给”，如果库里有这个字，就接着查“给国”，如果库里有，就接着查“给国家”比如查到“给国家和社会造”，数据库里没有这个词，那么将“给国家和社会”这个字符串写入listBox1，把“造成巨大损失”写入listBox2）请教大家我的这段代码应该怎么改才符合我的要求，谢谢！

Answer 1

存储过程写把.
 select * from XX where XX like %'给'%
......
select * from XX where XX like %'给国'%

Answer 2

using System; 
using System.Collections.Generic; 
using System.ComponentModel; 
using System.Data; 
using System.Drawing; 
using System.Text; 
using System.Windows.Forms; 
using System.Data.OleDb; namespace WindowsApplication3 
{ 
    public partial class Form1 : Form 
    { 
        public string Str; 
        public Form1() 
        { 
            InitializeComponent(); 
        }         private void button1_Click(object sender, EventArgs e) 
        { 
            int length = 0; 
            int count = 1; 
            
            string Str = textBox1.Text.ToString(); 
            string strConnection = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=e:/Dict.mdb;User ID=admin;Password=;Jet OLEDB:Database Password=123456"; 
            OleDbConnection objConnection = new OleDbConnection(strConnection); 
            objConnection.Open(); 
            OleDbCommand objCommand = null;            while(count > 0) 
            {
                 length = length + 1;   
                 string Str1 = Str.Substring(0, length);
                 string StrCon = "select count(1) from dict where Han like '" + Str1 + "%'"; 
                 objCommand = new OleDbCommand(StrCon, objConnection); 
                 count = Convert.ToInt32(objCommand.ExecuteScalar));                          
            }             listBox1.Items.Clear();
            listBox2.Items.Clear();            listBox1.Items.Add(Str.SubString(0, length - 1)); 
            listBox2.Items.Add(Str.SubString(length - 1));
        } 
    } 
} 

Answer 3

using System; 
using System.Collections.Generic; 
using System.ComponentModel; 
using System.Data; 
using System.Drawing; 
using System.Text; 
using System.Windows.Forms; 
using System.Data.OleDb; namespace WindowsApplication3 
{ 
    public partial class Form1 : Form 
    { 
        public string Str; 
        public Form1() 
        { 
            InitializeComponent(); 
        }         private void button1_Click(object sender, EventArgs e) 
        { 
            int length = 1; 
            int count = 1; 
            while(count>0) 
            { 
            Str = textBox1.Text.ToString(); 
            string Str1 = Str.Substring(0, length); 
            string strConnection = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=e:/Dict.mdb;User ID=admin;Password=;Jet OLEDB:Database Password=123456"; 
            OleDbConnection objConnection = new OleDbConnection(strConnection); 
            objConnection.Open(); 
            string StrCon = "select count(*) from dict where Han like '" + Str1 + "%'"; 
            OleDbCommand objCommand = new OleDbCommand(StrCon, objConnection); 
            count = Convert.ToInt32(objCommand.ExecuteScalar()); 
            length = length + 1; 
            if (count >0) 
            { 
                listBox1.Items.Add(Str1); 
            } 
            else 
            { 
                string Strsy = Str.Substring(Str1.ToString().Length, Str.ToString().Length); 
                listBox2.Items.Add(Strsy); 
                break; 
            }             } 
            
        } 
    } 
} 

Answer 4

string StrCon = "select count(*) from dict where Han like '%" + Str1 + "%'"; 
是这个意思吗?