C # Database Access static classes support multiple SQL statement transaction operations

Using System; <br/> using System. data; <br/> using System. data. sqlClient; <br/> using System. collections; </p> <p> namespace ReCard <br/>{< br/> public static class DB <br/>{</p> <p> private static SqlConnection connection = null; <br/> private static SqlCommand command = null; <br/> private static SqlDataAdapter adapter = null; <br/> private static string errorString; <br/> public static string ErrorStr Ing <br/>{< br/> get {return errorString ;} <br/>}</p> <p> // <summary> <br/> // initialization <br/> /// </summary> <br/> public static void Init (string ConnectionString) <br/>{< br/> connection = new SqlConnection (ConnectionString); <br/> command = connection. createCommand (); <br/> adapter = new SqlDataAdapter (); <br/> adapter. selectCommand = command; <br/>}</p> <p> // <summary> <br/> // open the connection. <br/> /// </Summary> <br/> /// <returns> </returns> <br/> public static bool Connect () <br/>{< br/> try <br/>{< br/> if (connection. state = ConnectionState. closed) <br/>{< br/> connection. open (); <br/>}< br/> return true; <br/>}< br/> catch (Exception) <br/>{< br/> return false; <br/>}</p> <p> // <summary> <br/> // close the connection <br/> // </summary> <br/> // <returns> </returns> <br/> public stat Ic bool CloseConnect () <br/>{< br/> try <br/>{< br/> if (connection. state = ConnectionState. open) <br/>{< br/> connection. close (); <br/>}< br/> return true; <br/>}< br/> catch (Exception) <br/>{< br/> return false; <br/>}</p> <p> // <summary> <br/> // retrieve data from the database based on the query statement <br/> /// </summary> <br/> /// <param name = "strSelect"> query statement </param> <br/> /// <returns> has the data returns the DataTable object, otherwise, null is returned. </r Eturns> <br/> public static DataTable DTSelect (string SelectString) <br/>{< br/> errorString = ""; <br/> try <br/> {<br/> if (connection. state = ConnectionState. closed) <br/>{< br/> connection. open (); <br/>}< br/> adapter. selectCommand. commandType = CommandType. text; <br/> adapter. selectCommand. commandText = SelectString; <br/> DataTable myDT = new DataTable (); <br/> adapter. fill (myDT); <br/> Return myDT; <br/>}< br/> catch (Exception ex) <br/>{< br/> errorString = "Data Query failed:" + ex. message; <br/> return null; <br/>}</p> <p> // <summary> <br/> // update the database based on SQL statements <br/>/ /// </summary> <br/> /// <param name = "UpdataString"> Update statement </param> <br/> /// <returns> returns true </returns> <br/> public static bool dbUpdate (string UpdataString) <br/>{< br/> errorString = ""; <br/> try <br/> {<br /> If (connection. state = ConnectionState. closed) <br/>{< br/> connection. open (); <br/>}< br/> command. commandType = CommandType. text; <br/> command. commandText = UpdataString; <br/> int intCount = command. executeNonQuery (); <br/> return intCount> 0; <br/>}< br/> catch (Exception ex) <br/>{< br/> errorString = "failed to update database:" + ex. message; <br/> return false; <br/>}</p> <p> // <summary> <Br/> // execute multiple SQL statements to implement database transactions. <Br/> /// </summary> <br/> /// <param name = "SQLStringList"> Multiple SQL statements </param> <br/> public static bool ExecuteSqlTran (ArrayList SQLStringList) <br/>{</p> <p> SqlTransaction tx = connection. beginTransaction (); <br/> command. transaction = tx; <br/> try <br/> {<br/> for (int n = 0; n <SQLStringList. count; n ++) <br/>{< br/> string strsql = SQLStringList [n]. toString (); <br/> if (strsql. trim (). length> 1) <br/>{< br/> command. commandText = strsql; <br/> command. executeNonQuery (); <br/>}< br/> tx. commit (); <br/> return true; <br/>}< br/> catch (Exception Etranca) <br/>{< br/> tx. rollback (); <br/> errorString = "database operation failed:" + Etranca. message; <br/> return false; <br/>}</p> <p >}< br/>