连接数据库
public static String connstr = "server=.;database=test2007;trusted_connection = true";
public static DataTable ExecuteTable (String Sql,params SqlParameter [] ps)
{
using(SqlConnection conn = new SqlConnection(connstr))
{
SqlDataAdapter sda = new SqlDataAdapter(Sql, conn);
sda.SelectCommand.Parameters.AddRange(ps);
DataTable dt = new DataTable();
sda.Fill(dt);
return dt;
}
}
public static int ExecuteNoquery(String Sql,params SqlParameter [] ps)
{
using(SqlConnection conn = new SqlConnection(connstr))
{
SqlCommand cmd = new SqlCommand(Sql, conn);
cmd.Parameters.AddRange(ps);
conn.Open();
return cmd.ExecuteNonQuery();
}
}
}
查询并写入文件
if (textBox1.Text.Length<1)
{
MessageBox.Show("姓名不能为空");
return;
}
DataTable dt = SqlHelper.ExecuteTable("select ENAME,OFFER,employee.DNO as DNO,DNAME,response from employee,department where employee.DNO = department.DNO and ENAME = @ENAME",new SqlParameter ("@ENAME",textBox1.Text));
dataGridView1.DataSource=dt;
if (dt.Rows.Count < 1)
{
MessageBox.Show("无相关信息");
}
WriteTxt(dt);
写入文件
StreamWriter wr;
if (File.Exists("aaa.txt"))
{
wr = File.AppendText("aaa.txt");
}
else
{
wr = File.CreateText("aaa.txt");
}
wr.WriteLine("姓名\t工资\t部门编号\t部门名字\t负责人");
foreach (DataRow dr in dt.Rows)
{
wr.WriteLine(dr[0].ToString() + "\t" + dr[1].ToString() + "\t" + dr[2].ToString() + "\t" + dr[3].ToString() + "\t" + dr[4].ToString());
}
wr.Close();
增删
private void button1_Click(object sender, EventArgs e)
{
int rows=SqlHelper.ExecuteNoquery("insert into employee values(@A,@B,@C,@D)", new SqlParameter("@A", textBox1.Text), new SqlParameter("@B", textBox2.Text), new SqlParameter("@C", textBox3.Text),new SqlParameter("@D",comboBox1.Text));
if (rows >= 1)
{
MessageBox.Show("添加成功");
}
}
private void button2_Click(object sender, EventArgs e)
{
int rows = SqlHelper.ExecuteNoquery("delete from employee where ENO = @ENO", new SqlParameter("@ENO", textBox1.Text));
if (rows >= 1)
{
MessageBox.Show("删除成功");
}
}
public static String connstr = "server=.;database=test2007;trusted_connection = true";
public static DataTable ExecuteTable (String Sql,params SqlParameter [] ps)
{
using(SqlConnection conn = new SqlConnection(connstr))
{
SqlDataAdapter sda = new SqlDataAdapter(Sql, conn);
sda.SelectCommand.Parameters.AddRange(ps);
DataTable dt = new DataTable();
sda.Fill(dt);
return dt;
}
}
public static int ExecuteNoquery(String Sql,params SqlParameter [] ps)
{
using(SqlConnection conn = new SqlConnection(connstr))
{
SqlCommand cmd = new SqlCommand(Sql, conn);
cmd.Parameters.AddRange(ps);
conn.Open();
return cmd.ExecuteNonQuery();
}
}
}
查询并写入文件
if (textBox1.Text.Length<1)
{
MessageBox.Show("姓名不能为空");
return;
}
DataTable dt = SqlHelper.ExecuteTable("select ENAME,OFFER,employee.DNO as DNO,DNAME,response from employee,department where employee.DNO = department.DNO and ENAME = @ENAME",new SqlParameter ("@ENAME",textBox1.Text));
dataGridView1.DataSource=dt;
if (dt.Rows.Count < 1)
{
MessageBox.Show("无相关信息");
}
WriteTxt(dt);
写入文件
StreamWriter wr;
if (File.Exists("aaa.txt"))
{
wr = File.AppendText("aaa.txt");
}
else
{
wr = File.CreateText("aaa.txt");
}
wr.WriteLine("姓名\t工资\t部门编号\t部门名字\t负责人");
foreach (DataRow dr in dt.Rows)
{
wr.WriteLine(dr[0].ToString() + "\t" + dr[1].ToString() + "\t" + dr[2].ToString() + "\t" + dr[3].ToString() + "\t" + dr[4].ToString());
}
wr.Close();
增删
private void button1_Click(object sender, EventArgs e)
{
int rows=SqlHelper.ExecuteNoquery("insert into employee values(@A,@B,@C,@D)", new SqlParameter("@A", textBox1.Text), new SqlParameter("@B", textBox2.Text), new SqlParameter("@C", textBox3.Text),new SqlParameter("@D",comboBox1.Text));
if (rows >= 1)
{
MessageBox.Show("添加成功");
}
}
private void button2_Click(object sender, EventArgs e)
{
int rows = SqlHelper.ExecuteNoquery("delete from employee where ENO = @ENO", new SqlParameter("@ENO", textBox1.Text));
if (rows >= 1)
{
MessageBox.Show("删除成功");
}
}