C# 数据库的操作
一：数据库连接代码：
SqlConnection objSqlConnection = new SqlConnection ("server = 127.0.0.1;uid = sa; pwd =;database =test");
objSqlConnection.Open();
二：数据库的添加记录代码： int i = 0;
string s1 = "", s2 = "";
i = Convert.ToInt16(textBox1.Text); s1 = textBox2.Text; s2 = textBox3.Text;
SqlConnection objSqlConnection = new SqlConnection("server = 127.0.0.1;uid = sa; pwd =;database =test");
objSqlConnection.Open();
MessageBox.Show("数据库连接成功", "好"); try {
SqlCommand sqlcom = new SqlCommand("insert into info(id,name,sex) values( " + i + ",'" + s1 + "','" + s2 + "')", objSqlConnection); sqlcom.ExecuteNonQuery();
MessageBox.Show("添加成功！", "啊"); }
catch (Exception a) {
MessageBox.Show(a.ToString()); }
MessageBox.Show("添加成功！", "啊"); }
三：数据库的修改代码： int i = 0;
string s1 = "", s2 = ""; s1 = textBox2.Text; s2 = textBox3.Text;
if (textBox1.Text.Length == 0) i = 0; else
i = Convert.ToInt32(textBox1.Text);
SqlConnection objSqlConnection = new SqlConnection("server = 127.0.0.1;uid = sa; pwd =;database =test");
objSqlConnection.Open();
MessageBox.Show("数据库连接成功", "好"); try {
SqlCommand
sqlcom = new SqlCommand("update info set
name='"+s1+"',sex='"+s2+"'"+"where id=" + i, objSqlConnection); sqlcom.ExecuteNonQuery();
MessageBox.Show("修改成功！", "啊"); objSqlConnection.Close(); }
catch (Exception a) {
MessageBox.Show(a.ToString()); }
四：数据库的删除代码： int i = 0;
string s1 = "", s2 = ""; s1 = textBox2.Text; s2 = textBox3.Text; if(textBox1.Text.Length==0) i=0;
else
i = Convert.ToInt16(textBox1.Text);
SqlConnection objSqlConnection = new SqlConnection("server = 127.0.0.1;uid = sa; pwd =;database =test");
objSqlConnection.Open();
MessageBox.Show("数据库连接成功", "好");
try {
SqlCommand sqlcom = new SqlCommand("delete from info where id="+i, objSqlConnection);
sqlcom.ExecuteNonQuery();
MessageBox.Show("删除成功！", "啊"); objSqlConnection.Close(); }
catch (Exception a) {
MessageBox.Show(a.ToString()); }
五：数据库的查询代码： 1.类开始：
DataTable dt1 = new DataTable();
SqlDataAdapter da1 = new SqlDataAdapter(); 2.按钮代码：
int i = 0,n=0;
string s1 = "", s2 = ""; s1 = textBox2.Text; s2 = textBox3.Text;
if (textBox1.Text.Length == 0) i = 0; else
i = Convert.ToInt32(textBox1.Text);
SqlConnection objSqlConnection = new SqlConnection("server = 127.0.0.1;uid = sa; pwd =;database =test");
objSqlConnection.Open();
MessageBox.Show("数据库连接成功", "好"); string query = "SELECT * from info where id="+i; DataSet objDataSet = new DataSet();
SqlDataAdapter obj = new SqlDataAdapter();
obj.SelectCommand = new SqlCommand(query, objSqlConnection); obj.Fill(objDataSet, "info");
SqlCommand objSqlCommand = new SqlCommand(query, objSqlConnection); SqlDataReader objSqlReader = objSqlCommand.ExecuteReader(); while (objSqlReader.Read())
{
n += 1;
MessageBox.Show("编号: " + objSqlReader.Getvalue(0) + " 姓名:" + objSqlReader.Getvalue(1) + " 性别" + objSqlReader.Getvalue(2)); }
if (n == 0)
MessageBox.Show("数据库中没有这样的记录！"); 六：数据库的查询代码： int i = 0;
// int n = 0;
string s1 = "", s2 = ""; string sql;
s1 = textBox2.Text;
s2 = textBox3.Text;
if (textBox1.Text.Length == 0) { i = 0; } else
i = Convert.ToInt32(textBox1.Text);
SqlConnection objSqlConnection = new SqlConnection("server = 127.0.0.1;uid = sa; pwd =;database =test");
objSqlConnection.Open();
MessageBox.Show("数据库连接成功", "好"); string query = "SELECT * from info where id="+i; if(i==0)
sql = "select * from info "; else
sql = "select * from info where id=" + i; da1 = new SqlDataAdapter(sql, objSqlConnection);
dt1.Clear();
da1.Fill(dt1);
dataGridView1.DataSource = dt1;
数据库的封装类代码： class DBClass {
public void dbclass(string sql) { try {
SqlConnection sqlcon = new SqlConnection("server = 127.0.0.1;uid = sa; pwd =;database =test");
sqlcon.Open();
SqlTransaction objt = sqlcon.BeginTransaction(); //事物开始
SqlCommand sqlcom = new SqlCommand(sql, sqlcon);
sqlcom.Transaction = objt; //将Command 对象设置为事物处理的对象
sqlcom.ExecuteNonQuery(); objt.Commit(); //提交事物 sqlcon.Close(); }
catch (Exception a) {
MessageBox.Show(a.ToString()); } } }
--db2 数据库连接代码：
string strcon = "Provider = IBMDADB2; Data Source=hfzd;User
Id=db2admin;Password=db2admin";
//string sql = "select * from ADMINISTRATOR.HFZD";
string sql = "delete from ADMINISTRATOR.HFZD where ID=1"; OleDbConnection olecon = new OleDbConnection(strcon); olecon.Open();
MessageBox.Show("数据库已连接上"); dt.Clear();
da = new OleDbDataAdapter(sql, olecon); da.Fill(dt);
dataGridView1.DataSource = dt; olecon.Close();
