C#和SQL Server2000数据库连接,查询语句总结

using System.Data;

using System.Data.SqlClient;

private SqlConnection myconn;

private SqlCommand mycomm;

一.单表

try
{

//插入记录
this.myconn=new SqlConnection();
this.myconn.ConnectionString= "workstation id=3BB9B810500D4AC;packet size=4096;integrated security=SSPI;data sou" + "rce=3BB9B810500D4AC;persist security info=False;initial catalog=Maintenance";
this.myconn.Open();

string insertString = string.Format(
"INSERT INTO salary VALUES ('{0}','{1}','{2}',{3},{4},'{5}')"
,number++,workerName,time,salary,prize,details);

this.mycomm=new SqlCommand();
this.mycomm.CommandText=insertString;
this.mycomm.Connection=this.myconn;

this.mycomm.ExecuteNonQuery();

MessageBox.Show(this,"员工工资的信息录入成功!","提示信息",
MessageBoxButtons.OK,MessageBoxIcon.Information);

this.txtSalary.Text="";
this.txtPrize.Text="";
this.txtDetails.Text="";
}
catch
{
MessageBox.Show(this,"员工工资的信息保存失败!","提示信息",
MessageBoxButtons.OK,MessageBoxIcon.Information);
}
finally
{
this.myconn.Close();
}

//修改记录

try
{
this.myconn=new SqlConnection();
this.myconn.ConnectionString= "workstation id=3BB9B810500D4AC;packet size=4096;integrated security=SSPI;data sou" +
"rce=3BB9B810500D4AC;persist security info=False;initial catalog=Maintenance";
this.myconn.Open();

string updateString="UPDATE salary SET 基本工资="+salary+",奖金="+prize+",备注='"+details+"' WHERE 员工姓名='"+workerName+"' AND 年月份='"+time+"'";

this.mycomm=new SqlCommand();
this.mycomm.CommandText=updateString;
this.mycomm.Connection=this.myconn;

this.mycomm.ExecuteNonQuery();

MessageBox.Show(this,"员工工资的信息保存成功!","提示信息",
MessageBoxButtons.OK,MessageBoxIcon.Information);

this.btnSaveUpdate.Enabled=false;

this.txtSalary.Text="";
this.txtPrize.Text="";
this.txtDetails.Text="";
}
catch
{
MessageBox.Show(this,"员工工资的信息保存失败!","提示信息",
MessageBoxButtons.OK,MessageBoxIcon.Information);
}
finally
{
this.myconn.Close();
}

//删除信息
if(result==DialogResult.OK)
{
try
{
string deleteString=String.Format("DELETE FROM worker_archives WHERE 员工姓名='{0}'",workerName);

this.myConn=new SqlConnection();
this.myConn.ConnectionString= "workstation id=3BB9B810500D4AC;packet size=4096;integrated security=SSPI;data sou" +
"rce=3BB9B810500D4AC;persist security info=False;initial catalog=Maintenance";
this.myConn.Open();

myComm=new SqlCommand();
myComm.Connection=this.myConn;
myComm.CommandText=deleteString;
myComm.ExecuteNonQuery();

this.rbBoy.Checked=false;
this.rbGirl.Checked=false;
this.txtAge.Text="";
this.txtAddress.Text="";
this.txtPhone.Text="";
this.txtMobilePhone.Text="";
this.txtStatus.Text="";
this.txtEmail.Text="";
}
finally
{
this.myConn.Close();
}

二.多表

//多表查询
string cmdText="SELECT RealName,Role_Name,Role_Description FROM Staff "
+"INNER JOIN StaffRole ON Staff.Staff_ID=StaffRole.Staff_ID "
+"INNER JOIN Role ON Role.Role_ID=StaffRole.Role_ID "
+"WHERE Staff.Staff_Name="
+"'"+sUserName+"'";

SqlConnection myConn=new SqlConnection(STRCONNECTION);
SqlCommand myComm=new SqlCommand(cmdText,myConn);

myConn.Open();
SqlDataReader dr=myComm.ExecuteReader();
string result="真实姓名为:";
if(dr.Read())
{
result+=dr["RealName"].ToString();
result+="<br>用户角色名为:";
result+=dr["Role_Name"].ToString();
result+="<br>角色描述为:";
result+=dr["Role_Description"].ToString();
result+="<br>";
}
else
{
result+="<br>用户角色为:";
result+="<br>角色描述为:";
}
dr.Close();
myConn.Close();