C # Database access method, used during an interview.

A database connection string that adds a SqlDataSource control to the page vs can be automatically generated and saved in a webconfig file.

<summary>
Description: Execsql is used to execute SQL statements. Used to perform query operations.
Return value: Whether the operation succeeded (True/false).
Parameters: SQL SQL string
Date Created: 2008-04-08
Create Person: Tianyu
</summary>
Public Boolean Execsql (String sql)
{

using (OleDbConnection con = new OleDbConnection (Sqlcon))
{
Con. Open ();
OleDbCommand DbCommand = new OleDbCommand (sql, con);
Try
{
Dbcommand.executenonquery ();
Con. Close ();
}
Catch
{
Con. Close ();
return false;
}
return true;
}
}

<summary>
Description: GetDataSet data set, return data set
Return Value: DataSet DataSet
Parameters: SQL SQL string, tablename temporary data table name
Date Created: 2008-04-08
Create Person: Tianyu
</summary>
Public System.Data.DataSet GetDataSet (String sql, string tablename)
{
using (OleDbConnection con = new OleDbConnection (Sqlcon))
{
Try
{
Con. Open ();
OleDbDataAdapter dbadapter = new OleDbDataAdapter (sql, con);
DataSet DataSet = new DataSet ();
Dbadapter.fill (DataSet, TableName);
Con. Close ();
return dataset;
}
Catch
{
Con. Close ();
return null;
}
}
}

<summary>
Get a dataset that intercepts a fixed row
</summary>
<param name= "SQL" > executed SQL statements </param>
<param name= "Start" > Start line </param>
<param name= "End" > Ending line </param>
<param name= "TableName" > The name of the temporary table generated </param>
<returns></returns>
Public System.Data.DataSet Getcutdataset (String sql, int start, int end, string tablename)
{
using (OleDbConnection con = new OleDbConnection (Sqlcon))
{
Try
{
Con. Open ();
OleDbDataAdapter dbadapter = new OleDbDataAdapter (sql, con);
DataSet DataSet = new DataSet ();
Dbadapter.fill (DataSet, Start, end, TableName);
Con. Close ();
return dataset;
}
Catch
{
Con. Close ();
return null;
}
}
}

<summary>
Determine whether data exists in the database based on the SQL statement.
The SQL statement to execute cannot include the count () statement.
</summary>
<param name= "SQL" > string to Query </param>
<returns> returns false </returns> if there is data return true
public bool HasData (String sql)
{
using (OleDbConnection con = new OleDbConnection (Sqlcon))
{
OleDbDataReader Dr;
Con. Open ();
OleDbCommand DbCommand = new OleDbCommand (sql, con);
Dr= Dbcommand.executereader ();
Try
{

if (Dr. Read ())
{
Dr. Close ();
Con. Close ();
return true;
}
Else
{
Dr. Close ();
Con. Close ();
return false;
}
}
Catch
{
Dr. Close ();
Con. Close ();
return false;
}

}

}