C#数据库操作——新建表、查询、删除、添加、更新等

转载自 豆夫 2010-7-5

数据库名：data.mdb;

内含一个表:table1;

table1有三列:日期、地点、人物，日期设为主键;

//////////////////////声明与定义////////////////////////

usingSystem.Data.OleDb

private string strCon = "Provider=Microsoft.Jet.OLEDB.4.0;DataSource=\"data.mdb\"";

private string strTableName;

private OleDbCommand myCommand = new OleDbCommand();

private OleDbConnection myConnection = new OleDbConnection();

private OleDbDataAdapter myAdapter = new OleDbDataAdapter();

private DataSet myDataSet = new DataSet();

////////////数据库记录操作的Sql语句/////////////////////////

查询：string strSearch = "SELECT * FROM table1 WHERE日期>=#" + this.dmBegin.ToString() + "# and日期<=#" + this.dmEnd.ToString() + "#";

string strSearch = "SELECT * FROM table1 WHERE 日期LIKE '%" + dm.ToString() + "%' OR 地点 LIKE '%" +this.textBox1.Text + "'";

删除：string strDel = "DELETE * FROM table1 WHERE 日期= '"+dm.ToString() + "'";

添加：string strInst = "INSERT INTO table1(日期,地点,人物) VALUES ('" +this.textBox1.Text + "','" + this.textBox2.Text + "','" +this.textBox3.Text + "')";

更新：string strUpdate = "UPDATE table1 SET" + " 地点='" +this.textBox1.Text + "',人物='" + this.textBox6.Text+ "'WHERE 日期='" + this.textBox5.Text + "'";

////////// 数据库操作代码//////////////////////////////

///获得数据库中的所有表的名称

this.myConnection.ConnectionString= this.strCon;

this.myConnection.Open(); ;

DataTable dt =myConnection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, newobject[] { null, null, null, "TABLE" });

foreach (DataRow dr in dt.Rows)

{

this.strTableName+=(String)dr["TABLE_NAME"]+"\n";

}

this.myConnection.Close();

//新建一个表，并增加记录,新表的名字为table2，第一列“日期”，date型数据，后面几列均为文本型

DataTable dtCurrent = new DataTable();

int nr = dtCurrent.Rows.Count;

int nc = dtCurrent.Columns.Count;

string StrCmd = "CREATE TABLE table2(" +dtCurrent.Columns[0].ColumnName.ToString() + " date,";

string strCol = dtCurrent.Columns[0].ColumnName.ToString() +",";

for (int i = 1; i < nc - 1; i++)

{

StrCmd =StrCmd + dtCurrent.Columns[i].ColumnName.ToString() + "nvarchar(200),";

strCol =strCol + dtCurrent.Columns[i].ColumnName.ToString() + ",";

}

StrCmd = StrCmd + dtCurrent.Columns[nc - 1].ColumnName.ToString() +" nvarchar(200))";

strCol = strCol + dtCurrent.Columns[nc -1].ColumnName.ToString();

this.myConnection.ConnectionString =this.strCon;

this.myCommand.Connection = this.myConnection;

this.myCommand.CommandText = StrCmd;

this.myConnection.Open();

this.myCommand.ExecuteNonQuery();

for (int i = 0; i < nr - 1; i++)

{

stringstrInsert = " INSERT INTO table2(" + strCol + ") VALUES ( '";

strInsert +=Convert.ToDateTime(dtCurrent.Rows[i][0].ToString()) + "','";

for (int j =1; j < nc - 1; j++)

{

strInsert += dtCurrent.Rows[i][j].ToString() + "','";

}

strInsert +=dtCurrent.Rows[i][nc - 1].ToString() + "')";

this.myCommand.CommandText = strInsert;

this.myCommand.ExecuteNonQuery();

}

this.myConnection.Close();

//查询读取记录

public voiddbSearch()

{

this.myConnection.Open();

try

{

this.myCommand.CommandText = strSearch ;//查询多有用"SELECT * FROMtable1";

this.myCommand.Connection = this.myConnection;

this.myAdapter.SelectCommand =this.myCommand;

this.myDataSet.Clear();

this.myAdapter.Fill(this.myDataSet);

this.myConnection.Close();

dataGridViewBook.DataSource = this.myDataSet.Tables[0];

}

catch(Exception ex)

{

this.myConnection.Close();

MessageBox.Show(ex.Message);

}

this.myConnection.Close();

}

//新建记录

private void dbInst()

{

this.myCommand.CommandText = strInst

this.myAdapter.InsertCommand = this.myCommand;

try

{

this.myAdapter.InsertCommand.Connection.Open();

this.myAdapter.InsertCommand.ExecuteNonQuery();

}

catch(Exception ex)

{

this.myAdapter.InsertCommand.Connection.Close();

MessageBox.Show(ex.Message);

}

this.myAdapter.InsertCommand.Connection.Close();

}

//删除记录

private void dbDel()

{

this.myCommand.CommandText = strDel;

this.myAdapter.DeleteCommand = this.myCommand;

this.myAdapter.DeleteCommand.Connection.Open();

try

{

this.myAdapter.DeleteCommand.ExecuteNonQuery();

}

catch(Exception ex)

{

this.myAdapter.DeleteCommand.Connection.Close();

MessageBox.Show(ex.Message);

}

this.myAdapter.DeleteCommand.Connection.Close();

}

//更新记录

private void dbUpdate()

{

this.myCommand.CommandText = strUpdate;

this.myAdapte.UpdateCommand =this.myCommand;

try

{

this.myAdapter.UpdateCommand.Connection.Open();

this.myAdapter.UpdateCommand.ExecuteNonQuery();

}

catch(Exception ex)

{

this.myAdapter.UpdateCommand.Connection.Close();

MessageBox.Show(ex.Message);

}

this.myAdapter.UpdateCommand.Connection.Close();

}

//上下移动数据库的记录

privateBindingManagerBase Mybind;

this.Mybind = this.BindingContext[this.myDataSet.Tables[0]];

this.Mybind.Position = 0;

Mybind.Position--;

Mybind.Position++;