Ｓｅｌｅｃｔ语句的模糊查询。


/// <summary>
/// 应用程序的主入口点。
/// </summary>
[STAThread]
static void Main() 
{
Application.Run(new frmBookManage());
}

private void btnExit_Click(object sender, System.EventArgs e)
{
myCon.Close();//关闭连接
Application.Exit();//退出程序
}

private void frmBookManage_Load(object sender, System.EventArgs e)
{
//连接对象
myCon = new OleDbConnection();
myCon.ConnectionString = "Provider = Microsoft.Jet.OLEDB.4.0;"+"Data source ="+Application.StartupPath +@"\LibraryInfo.mdb";
myCon.Open();//打开数据库连接

OleDbCommand myCom = new OleDbCommand("select SortName from SortInfo",myCon);

myRd = myCom.ExecuteReader();
while(myRd.Read()==true)
{
cmbInfo.Items.Add(myRd["SortName"]);
}
myRd.Close();
}

private void btnView_Click(object sender, System.EventArgs e)
{
if(cmbInfo.Text=="" && txtBookName.Text=="" && txtAuthor.Text=="")
{
OleDbDataAdapter myAd = new OleDbDataAdapter("select BookId as 类别名称,BookName as 图书名称,BookAuthor as 作者,BookPublish as 出版社 from BookInfo ",myCon);
DataSet myDs = new DataSet();
myAd.Fill(myDs,"BookInfo");
dataGrid1.DataSource=myDs.Tables[0];
}
else 
if(cmbInfo.Text=="" && txtBookName.Text=="")
{
OleDbDataAdapter myAd = new OleDbDataAdapter("select BookName as 图书名称,BookAuthor as 作者,BookPublish as 出版社 from BookInfo where BookAuthor='"+txtAuthor.Text+"' ",myCon);
DataSet myDs = new DataSet();
myAd.Fill(myDs,"BookInfo");
dataGrid1.DataSource=myDs.Tables[0];
}
else 
if(cmbInfo.Text=="" && txtAuthor.Text=="")
{
OleDbDataAdapter myAd = new OleDbDataAdapter("select BookName as 图书名称,BookAuthor as 作者,BookPublish as 出版社 from BookInfo where BookName='"+txtBookName.Text+"'",myCon);
DataSet myDs = new DataSet();
myAd.Fill(myDs,"BookInfo");
dataGrid1.DataSource=myDs.Tables[0];
}
else 
if(cmbInfo.Text=="")
{
OleDbDataAdapter myAd = new OleDbDataAdapter("select BookName as 图书名称,BookAuthor as 作者,BookPublish as 出版社 from BookInfo where BookName='"+txtBookName.Text+"' and BookAuthor='"+txtAuthor.Text+"'",myCon);
DataSet myDs = new DataSet();
myAd.Fill(myDs,"BookInfo");
dataGrid1.DataSource=myDs.Tables[0];
}
else 
if(cmbInfo.Text=="小说")
{
OleDbDataAdapter myAd = new OleDbDataAdapter("select BookName as 图书名称,BookAuthor as 作者,BookPublish as 出版社 from BookInfo where SortId=1",myCon);
DataSet myDs = new DataSet();
myAd.Fill(myDs,"BookInfo");
dataGrid1.DataSource=myDs.Tables[0];
}
else 
if(cmbInfo.Text=="计算机")
{
OleDbDataAdapter myAd = new OleDbDataAdapter("select BookName as 图书名称,BookAuthor as 作者,BookPublish as 出版社 from BookInfo where SortId=2",myCon);
DataSet myDs = new DataSet();
myAd.Fill(myDs,"BookInfo");
dataGrid1.DataSource=myDs.Tables[0];
}
else 
if(cmbInfo.Text=="求职")
{
OleDbDataAdapter myAd = new OleDbDataAdapter("select BookName as 图书名称,BookAuthor as 作者,BookPublish as 出版社 from BookInfo where SortId=3",myCon);
DataSet myDs = new DataSet();
myAd.Fill(myDs,"BookInfo");
dataGrid1.DataSource=myDs.Tables[0];<