C # Connect to an Access database, C # Connect to an Excel database, C # Connect SQL Server database, C # connect MySQL database summary

Sophomore writing next semester, now graduated one months, finishing

Well, the previous writing is very naïve, only self-understanding, online a lot of, probably the meaning of the next bar

mysql=========================================

http://user.qzone.qq.com/652768664/blog/1347859952

To connect MySQL needs to install MySQL, in the MySQL C-disk installation directory has a connection lib, will change the Lib Add reference with the project OK;

 static            void Main (string[] args) {list<string> lstdb =mysqlconn ();            foreach (string s in Lstdb) {Console.WriteLine (s);        } console.read (); } public static list<string> Mysqlconn () {list<string> lstconn = new list<string&            gt; ();            Mysqlconnection objconn = new Mysqlconnection (); objconn.connectionstring = "server=127.0.0.1; User Id=root; password=000000;            Persist Security info=true;database=test ";            objConn.Open ();            Mysqlcommand objcmd = new Mysqlcommand ("SELECT * from Maya", objconn);            Mysqldatareader dr = Objcmd.executereader (); while (Dr. Read ()) {Lstconn. ADD (Dr[0].            ToString ());            } objconn.close ();        return lstconn; }    }

access==========================================

http://user.qzone.qq.com/652768664/blog/1334636397

Access2007 and Access 2003 have different connection strings, one ADO version 12.0 and one is 4.0;

1,

 Public list<string> Access2007 (string accdbpath,string tablename) {list<string> Lstdata =            New List<string> ();            String strconn = @ "Provider=microsoft.ace.oledb.12.0;data source=" + Accdbpath + "'";            OleDbConnection conn = new OleDbConnection (strconn); Conn.            Open ();            String cmdtext = "SELECT * from" + tablename+ "";            OleDbDataAdapter apdate = new OleDbDataAdapter (CMDTEXT, conn);            DataTable table = new DataTable (); Apdate.            Fill (table); if (table. Rows.Count > 0) {for (int irow = 0; irow < table. Rows.Count; irow++) for (int icol = 0; icol < table. Columns.count; icol++) Lstdata. Add ("Row:" + IRow + "Column:" + Icol + "ColumnName:" + table. Columns[icol]. ColumnName + "Value:" + table. Rows[irow][table. Columns[icol]. CoLumnname]);        } return lstdata; }

2,

Namespace message Board _access database _{public partial class _default:system.web.ui.page {string strconnection = "Provid er=microsoft.jet.oledb.4.0;        Data source=f:\\ message board. mdb ";        string sex; protected void Page_Load (object sender, EventArgs e) {OleDbConnection coon = new OleDbConnection (Strcon            Nection); Coon.            Open (); Response.Write ("Access database connection Status display:" + coon.)            State); Coon.            Close ();            Label1.text=datetime.now.tostring ();            if (radiobutton1.checked) {sex = "male";}        else {sex = "female";}        } protected void button1_click (object sender, EventArgs e) {TextBox2.Text = ""; } public void Seek (string str) {using (OleDbConnection coon = new OleDbConnection (strconnection)                ) {OleDbCommand cmd = new OleDbCommand (str, coon); try {coon.                    Open (); OleDbDataReader R= cmd.                    ExecuteReader (); while (R.read ()) TextBox3.Text = string.                Format ("message person: {0}; Gender: {1}; message content: {2}; message time {3}", R[0], r[1], r[2],r[4]); } catch (Exception ee) {Response.Write (EE.                Message); }}} public void Insert (string str) {using (OleDbConnection coon = new OLE DB                Connection (strconnection)) {OleDbCommand cmd = new OleDbCommand (str, coon); try {coon.                    Open (); Cmd.                    ExecuteNonQuery (); Response.Write ("<script>window.alert (' data added successfully! ');                                    </script> "); } catch (Exception ee) {Response.Write (EE.                Message); }}} protected void Button2_Click (object sender, EventArgs e) {Seek ("Select* from message board WHERE name = ' "+ TextBox1.Text.Trim () +" ' "); } protected void Button3_Click (object sender, EventArgs e) {Insert ("INSERT into message board (name, gender, message content, left The words time) VALUES (' "+textbox1.text.trim () +" ', ' "+sex.            Trim () + "', '" +textbox2.text.trim () + "', '" +label1.text+ "')");        Button2_Click (sender,e); }    }}

excel==========================================

http://user.qzone.qq.com/652768664/blog/1350139919

Class Excelinandout
{
Reading an Excel document
</summary>
<param name= "Path" > File name </param>
<returns> Returns a dataset </returns>
Public DataSet exceltods (string Path)
{
String strconn = "provider=microsoft.jet.oledb.4.0;" + "Data source=" + Path + ";" + "Extended properties=excel 8.0;";
OleDbConnection conn = new OleDbConnection (strconn);
Conn. Open ();
String strexcel = "";
OleDbDataAdapter mycommand = null;
DataSet ds = null;
Strexcel = "SELECT * FROM [sheet1$]";
mycommand = new OleDbDataAdapter (Strexcel, strconn);
ds = new DataSet ();
Mycommand.fill (ds, "Table1");
return DS;
}
}

SQL Server and sqllite==========================================

A server name is. A server name of. \SQLExpress