C#使用Ado.Net读写数据库

C#使用Ado.Net读写数据库

记性不好，记几个C#使用Ado.Net读写数据库的方式，以便随时取用.

1.使用DataReader方式读取资料

String connString = ConfigurationManager.ConnectionStrings["astt"].ConnectionString;

//如果数据库连接字符串有加密,可以经过解密后重新获得连接字符串
DbConnectionStringBuilder connBuilder = new DbConnectionStringBuilder();
connBuilder.ConnectionString = connString;
connBuilder["Data Source"] = connBuilder["Data Source"];  //可加上解密方法
connBuilder["User ID"] = connBuilder["User ID"];          //可加上解密方法
connBuilder["Password"] = connBuilder["Password"];        //可加上解密方法
connString = connBuilder.ConnectionString;

using (OleDbConnection conn = new OleDbConnection(connString))
{
try
{
conn.Open();

using (OleDbCommand cmd = new OleDbCommand())
{
cmd.CommandText = "select * from s_userm where rownum <= ?";
cmd.CommandType = CommandType.Text;
cmd.Connection = conn;
cmd.Parameters.Add("?", OleDbType.Integer).Value = 5;  //cmd.Parameters.Add(new OleDbParameter("?", 5));

using (OleDbDataReader reader = cmd.ExecuteReader())
{
while (reader.Read())
{
MessageBox.Show(reader.GetString(1), "资料");
}
}
}
conn.Close();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "error");
return;
}
}

2.使用DataAdapter与DataSet方式读取资料.

String connString = ConfigurationManager.ConnectionStrings["astt"].ConnectionString;
using (OleDbConnection conn = new OleDbConnection(connString))
{
try
{
using (OleDbCommand cmd = new OleDbCommand())
{
cmd.CommandText = "select * from s_userm where rownum <= ?";
cmd.CommandType = CommandType.Text;
cmd.Connection = conn;
cmd.Parameters.Add("?", OleDbType.Integer).Value = 5;  //cmd.Parameters.Add(new OleDbParameter("?", 5));

DataSet ds = new DataSet();
OleDbDataAdapter adapter = new OleDbDataAdapter(cmd);

adapter.Fill(ds, "s_userm");

foreach (DataRow dr in ds.Tables[0].Rows)
{
MessageBox.Show(Convert.ToString(dr["user_nm"]), "资料");
}

//listBox1.DataSource = ds.Tables[0].DefaultView;
//listBox1.DisplayMember = "user_nm";
//listBox1.ValueMember = "user_no";
listBox1.DataSource = ds;
listBox1.DisplayMember = "s_userm.user_nm";
listBox1.ValueMember = "s_userm.user_no";

dataGridView1.DataSource = ds.Tables[0].DefaultView;
dataGridView1.ReadOnly = true;
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "error");
return;
}
}

3.使用DataAdapter与DataSet对单表的增删改查，根据Command的查询语法，使用CommandBuilder自动生成增删改的语法.

String connString = ConfigurationManager.ConnectionStrings["astt"].ConnectionString;

using (OleDbConnection conn = new OleDbConnection(connString))
{
OleDbCommand cmd = new OleDbCommand();
cmd.CommandText = "select * from s_userm where rownum <= ?";
cmd.CommandType = CommandType.Text;
cmd.Connection = conn;
cmd.Parameters.Add("?", OleDbType.Integer).Value = 5;
OleDbDataAdapter adapter = new OleDbDataAdapter(cmd);

//使用DataAdapter更新单表，可以使用CommandBuilder来自动生成InsertCommand,UpdateCommand,DeleteCommand
OleDbCommandBuilder cmdbuilder = new OleDbCommandBuilder(adapter); //将自动生成InsertCommand,UpdateCommand,DeleteCommand
MessageBox.Show(cmdbuilder.GetUpdateCommand().CommandText, "updcommand");

//select
DataSet ds = new DataSet();
adapter.Fill(ds,"s_userm");
dataGridView1.DataSource = ds.Tables["s_userm"].DefaultView;

//insert
DataRow updateRow = ds.Tables["s_userm"].NewRow();
updateRow["user_no"] = "TEST1";
updateRow["user_nm"] = "test1";
ds.Tables["s_userm"].Rows.Add(updateRow);
adapter.Update(ds, "s_userm");

MessageBox.Show(Convert.ToString(ds.Tables["s_userm"].Rows[0]["user_no"]), "user");

//update
ds.Tables[0].Rows[1]["EMAIL"] = "gymsoft@163.com";
adapter.Update(ds, "s_userm");

//delete
ds.Tables["s_userm"].Rows[0].Delete();
adapter.Update(ds, "s_userm");
}

4.使用DataAdapter与DataSet进行增删改查，手动指定增删改查的语法。

String connString = ConfigurationManager.ConnectionStrings["astt"].ConnectionString;

using (OleDbConnection conn = new OleDbConnection(connString))
{
DataSet ds = new DataSet();
OleDbDataAdapter adapter = new OleDbDataAdapter();

//指定DataAdapter的select语句
OleDbCommand selectCmd = new OleDbCommand();
selectCmd.CommandText = "select * from s_userm where rownum <= ?";
selectCmd.CommandType = CommandType.Text;
selectCmd.Connection = conn;
selectCmd.Parameters.Add("?", OleDbType.Integer).Value = 5;
adapter.SelectCommand = selectCmd;

//指定DataAdapter的Insert语句
OleDbCommand insertCmd = new OleDbCommand();
insertCmd.CommandText = "insert into s_userm(user_no,user_nm) values(?,?)";
insertCmd.CommandType = CommandType.Text;
insertCmd.Connection = conn;
insertCmd.Parameters.Add("?", OleDbType.VarChar, 30, "user_no");
insertCmd.Parameters.Add("?", OleDbType.VarChar, 80, "user_nm");
adapter.InsertCommand = insertCmd;

//指定DataAdapter的Update语句
OleDbCommand updateCmd = new OleDbCommand();
updateCmd.CommandText = "update s_userm set email = ? where user_no = ?";
updateCmd.CommandType = CommandType.Text;
updateCmd.Connection = conn;
updateCmd.Parameters.Add("?", OleDbType.VarChar, 50, "email");
OleDbParameter parmUpdPk = updateCmd.Parameters.Add("?", OleDbType.VarChar, 30, "user_no");
parmUpdPk.SourceVersion = DataRowVersion.Original;
adapter.UpdateCommand = updateCmd;

//指定DataAdapter的Delete语句
OleDbCommand deleteCmd = new OleDbCommand();
deleteCmd.CommandText = "delete from s_userm where user_no = ?";
deleteCmd.CommandType = CommandType.Text;
deleteCmd.Connection = conn;
OleDbParameter parmDelPk = deleteCmd.Parameters.Add("?", OleDbType.VarChar, 30, "user_no");
parmDelPk.SourceVersion = DataRowVersion.Original;
adapter.DeleteCommand = deleteCmd;

MessageBox.Show(adapter.SelectCommand.CommandText, "command");

//select
adapter.Fill(ds, "s_userm");
dataGridView1.DataSource = ds.Tables["s_userm"].DefaultView;

//insert
DataRow updateRow = ds.Tables["s_userm"].NewRow();
updateRow["user_no"] = "TEST2";
updateRow["user_nm"] = "test2";
ds.Tables["s_userm"].Rows.Add(updateRow);
adapter.Update(ds, "s_userm");

MessageBox.Show(Convert.ToString(ds.Tables["s_userm"].Rows[3]["user_no"]), "user");

//update
ds.Tables[0].Rows[3]["EMAIL"] = "gymsoft@163.com";
adapter.Update(ds, "s_userm");

//delete
ds.Tables["s_userm"].Rows[3].Delete();
adapter.Update(ds, "s_userm");
}

5.使用DataGridView绑定数据源进行编辑，使用DataAdapter与DataSet进行增删改查，手动指定增删改查的语法。

public partial class Form1 : Form
{
String connString;
OleDbConnection conn;
DataSet ds;
OleDbDataAdapter adapter;

public Form1()
{
InitializeComponent();
}

private void buttonQuery_Click(object sender, EventArgs e)
{
connString = ConfigurationManager.ConnectionStrings["astt"].ConnectionString;
conn = new OleDbConnection(connString);

ds = new DataSet();
adapter = new OleDbDataAdapter();

//指定DataAdapter的select语句
OleDbCommand selectCmd = new OleDbCommand();
selectCmd.CommandText = "select * from s_userm where rownum <= ?";
selectCmd.CommandType = CommandType.Text;
selectCmd.Connection = conn;
selectCmd.Parameters.Add("?", OleDbType.Integer).Value = 5;
adapter.SelectCommand = selectCmd;

//指定DataAdapter的Insert语句
OleDbCommand insertCmd = new OleDbCommand();
insertCmd.CommandText = "insert into s_userm(user_no,user_nm) values(?,?)";
insertCmd.CommandType = CommandType.Text;
insertCmd.Connection = conn;
insertCmd.Parameters.Add("?", OleDbType.VarChar, 30, "user_no");
insertCmd.Parameters.Add("?", OleDbType.VarChar, 80, "user_nm");
adapter.InsertCommand = insertCmd;

//指定DataAdapter的Update语句
OleDbCommand updateCmd = new OleDbCommand();
updateCmd.CommandText = "update s_userm set email = ? where user_no = ?";
updateCmd.CommandType = CommandType.Text;
updateCmd.Connection = conn;
updateCmd.Parameters.Add("?", OleDbType.VarChar, 50, "email");
OleDbParameter parmUpdPk = updateCmd.Parameters.Add("?", OleDbType.VarChar, 30, "user_no");
parmUpdPk.SourceVersion = DataRowVersion.Original;
adapter.UpdateCommand = updateCmd;

//指定DataAdapter的Delete语句
OleDbCommand deleteCmd = new OleDbCommand();
deleteCmd.CommandText = "delete from s_userm where user_no = ?";
deleteCmd.CommandType = CommandType.Text;
deleteCmd.Connection = conn;
OleDbParameter parmDelPk = deleteCmd.Parameters.Add("?", OleDbType.VarChar, 30, "user_no");
parmDelPk.SourceVersion = DataRowVersion.Original;
adapter.DeleteCommand = deleteCmd;

//MessageBox.Show(adapter.SelectCommand.CommandText, "command");

//select
adapter.Fill(ds, "s_userm");
dataGridView1.DataSource = ds.Tables["s_userm"].DefaultView;
}

private void buttonSave_Click(object sender, EventArgs e)
{
adapter.Update(ds, "s_userm");

ds.Clear();
adapter.Fill(ds, "s_userm");
dataGridView1.DataSource = ds.Tables["s_userm"].DefaultView;
}
}

6.使用DataAdapter与DataSet，以事务的方式进行增删改查。

String connString = ConfigurationManager.ConnectionStrings["astt"].ConnectionString;

using (OleDbConnection conn = new OleDbConnection(connString))
{
DataSet ds = new DataSet();
OleDbDataAdapter adapter = new OleDbDataAdapter();

//指定DataAdapter的select语句
OleDbCommand selectCmd = new OleDbCommand();
selectCmd.CommandText = "select * from s_userm where rownum <= ?";
selectCmd.CommandType = CommandType.Text;
selectCmd.Connection = conn;
selectCmd.Parameters.Add("?", OleDbType.Integer).Value = 5;
adapter.SelectCommand = selectCmd;

//指定DataAdapter的Insert语句
OleDbCommand insertCmd = new OleDbCommand();
insertCmd.CommandText = "insert into s_userm(user_no,user_nm) values(?,?)";
insertCmd.CommandType = CommandType.Text;
insertCmd.Connection = conn;
insertCmd.Parameters.Add("?", OleDbType.VarChar, 30, "user_no");
insertCmd.Parameters.Add("?", OleDbType.VarChar, 80, "user_nm");
adapter.InsertCommand = insertCmd;

//指定DataAdapter的Update语句
OleDbCommand updateCmd = new OleDbCommand();
updateCmd.CommandText = "update s_userm set email = ? where user_no = ?";
updateCmd.CommandType = CommandType.Text;
updateCmd.Connection = conn;
updateCmd.Parameters.Add("?", OleDbType.VarChar, 50, "email");
OleDbParameter parmUpdPk = updateCmd.Parameters.Add("?", OleDbType.VarChar, 30, "user_no");
parmUpdPk.SourceVersion = DataRowVersion.Original;
adapter.UpdateCommand = updateCmd;

//指定DataAdapter的Delete语句
OleDbCommand deleteCmd = new OleDbCommand();
deleteCmd.CommandText = "delete from s_userm where user_no = ?";
deleteCmd.CommandType = CommandType.Text;
deleteCmd.Connection = conn;
OleDbParameter parmDelPk = deleteCmd.Parameters.Add("?", OleDbType.VarChar, 30, "user_no");
parmDelPk.SourceVersion = DataRowVersion.Original;
adapter.DeleteCommand = deleteCmd;

//MessageBox.Show(adapter.SelectCommand.CommandText, "command");

conn.Open();
using (OleDbTransaction tran = conn.BeginTransaction(IsolationLevel.ReadCommitted))
{
adapter.SelectCommand.Transaction = tran;
adapter.InsertCommand.Transaction = tran;
adapter.UpdateCommand.Transaction = tran;
adapter.DeleteCommand.Transaction = tran;

try
{
//select
adapter.Fill(ds, "s_userm");
dataGridView1.DataSource = ds.Tables["s_userm"].DefaultView;

//insert
DataRow updateRow = ds.Tables["s_userm"].NewRow();
updateRow["user_no"] = "TEST2";
updateRow["user_nm"] = "test2";
ds.Tables["s_userm"].Rows.Add(updateRow);
adapter.Update(ds, "s_userm");

//MessageBox.Show(Convert.ToString(ds.Tables["s_userm"].Rows[3]["user_no"]), "user");

//update
ds.Tables[0].Rows[3]["EMAIL"] = "gymsoft@163.com";
adapter.Update(ds, "s_userm");

//delete
ds.Tables["s_userm"].Rows[3].Delete();
adapter.Update(ds, "s_userm");

tran.Commit();
}
catch (Exception ex)
{
try
{
tran.Rollback();
}
catch (Exception exc)
{
MessageBox.Show(exc.Message, "error");
}
MessageBox.Show(ex.Message, "error");
}
}
conn.Close();
}