using System;using System.Data;using System.Text.RegularExpressions;using System.Xml;using System.IO;using System.Collections;using System.Data.SQLite;namespace DBUtility.SQLite{ /// <summary> /// SQLiteHelper is a utility class similar to "SQLHelper" in MS /// Data Access Application Block and follows similar pattern. /// </summary> public class SQLiteHelper {  /// <summary>  /// Creates a new <see cref="SQLiteHelper"/> instance. The ctor is marked private since all members are static.  /// </summary>  private SQLiteHelper()  {  }  /// <summary>  /// Creates the command.  /// </summary>  /// <param name="connection">Connection.</param>  /// <param name="commandText">Command text.</param>  /// <param name="commandParameters">Command parameters.</param>  /// <returns>SQLite Command</returns>  public static SQLiteCommand CreateCommand(SQLiteConnection connection, string commandText, params SQLiteParameter[] commandParameters)  {   SQLiteCommand cmd = new SQLiteCommand(commandText, connection);   if (commandParameters.Length > 0)   {    foreach (SQLiteParameter parm in commandParameters)     cmd.Parameters.Add(parm);   }   return cmd;  }  /// <summary>  /// Creates the command.  /// </summary>  /// <param name="connectionString">Connection string.</param>  /// <param name="commandText">Command text.</param>  /// <param name="commandParameters">Command parameters.</param>  /// <returns>SQLite Command</returns>  public static SQLiteCommand CreateCommand(string connectionString, string commandText, params SQLiteParameter[] commandParameters)  {   SQLiteConnection cn = new SQLiteConnection(connectionString);   SQLiteCommand cmd = new SQLiteCommand(commandText, cn);   if (commandParameters.Length > 0)   {    foreach (SQLiteParameter parm in commandParameters)     cmd.Parameters.Add(parm);   }   return cmd;  }  /// <summary>  /// Creates the parameter.  /// </summary>  /// <param name="parameterName">Name of the parameter.</param>  /// <param name="parameterType">Parameter type.</param>  /// <param name="parameterValue">Parameter value.</param>  /// <returns>SQLiteParameter</returns>  public static SQLiteParameter CreateParameter(string parameterName, System.Data.DbType parameterType, object parameterValue)  {   SQLiteParameter parameter = new SQLiteParameter();   parameter.DbType = parameterType;   parameter.ParameterName = parameterName;   parameter.Value = parameterValue;   return parameter;  }  /// <summary>  /// Shortcut method to execute dataset from SQL Statement and object[] arrray of parameter values  /// </summary>  /// <param name="connectionString">SQLite Connection string</param>  /// <param name="commandText">SQL Statement with embedded "@param" style parameter names</param>  /// <param name="paramList">object[] array of parameter values</param>  /// <returns></returns>  public static DataSet ExecuteDataSet(string connectionString, string commandText, object[] paramList)  {   SQLiteConnection cn = new SQLiteConnection(connectionString);   SQLiteCommand cmd = cn.CreateCommand();   cmd.CommandText = commandText;   if (paramList != null)   {    AttachParameters(cmd,commandText, paramList);   }   DataSet ds = new DataSet();   if (cn.State == ConnectionState.Closed)    cn.Open();   SQLiteDataAdapter da = new SQLiteDataAdapter(cmd);   da.Fill(ds);   da.Dispose();   cmd.Dispose();   cn.Close();   return ds;  }  /// <summary>  /// Shortcut method to execute dataset from SQL Statement and object[] arrray of parameter values  /// </summary>  /// <param name="cn">Connection.</param>  /// <param name="commandText">Command text.</param>  /// <param name="paramList">Param list.</param>  /// <returns></returns>  public static DataSet ExecuteDataSet(SQLiteConnection cn, string commandText, object[] paramList)  {   SQLiteCommand cmd = cn.CreateCommand();   cmd.CommandText = commandText;   if (paramList != null)   {    AttachParameters(cmd,commandText, paramList);   }   DataSet ds = new DataSet();   if (cn.State == ConnectionState.Closed)    cn.Open();   SQLiteDataAdapter da = new SQLiteDataAdapter(cmd);   da.Fill(ds);   da.Dispose();   cmd.Dispose();   cn.Close();   return ds;  }  /// <summary>  /// Executes the dataset from a populated Command object.  /// </summary>  /// <param name="cmd">Fully populated SQLiteCommand</param>  /// <returns>DataSet</returns>  public static DataSet ExecuteDataset(SQLiteCommand cmd)  {   if (cmd.Connection.State == ConnectionState.Closed)    cmd.Connection.Open();   DataSet ds = new DataSet();   SQLiteDataAdapter da = new SQLiteDataAdapter(cmd);   da.Fill(ds);   da.Dispose();   cmd.Connection.Close();   cmd.Dispose();   return ds;  }  /// <summary>  /// Executes the dataset in a SQLite Transaction  /// </summary>  /// <param name="transaction">SQLiteTransaction. Transaction consists of Connection, Transaction, /// and Command, all of which must be created prior to making this method call. </param>  /// <param name="commandText">Command text.</param>  /// <param name="commandParameters">Sqlite Command parameters.</param>  /// <returns>DataSet</returns>  /// <remarks>user must examine Transaction Object and handle transaction.connection .Close, etc.</remarks>  public static DataSet ExecuteDataset(SQLiteTransaction transaction, string commandText, params SQLiteParameter[] commandParameters)  {   if (transaction == null) throw new ArgumentNullException("transaction");   if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rolled back or committed, please provide an open transaction.", "transaction");   IDbCommand cmd = transaction.Connection.CreateCommand();   cmd.CommandText = commandText;   foreach (SQLiteParameter parm in commandParameters)   {    cmd.Parameters.Add(parm);   }   if (transaction.Connection.State == ConnectionState.Closed)    transaction.Connection.Open();   DataSet ds = ExecuteDataset((SQLiteCommand)cmd);   return ds;  }  /// <summary>  /// Executes the dataset with Transaction and object array of parameter values.  /// </summary>  /// <param name="transaction">SQLiteTransaction. Transaction consists of Connection, Transaction, /// and Command, all of which must be created prior to making this method call. </param>  /// <param name="commandText">Command text.</param>  /// <param name="commandParameters">object[] array of parameter values.</param>  /// <returns>DataSet</returns>  /// <remarks>user must examine Transaction Object and handle transaction.connection .Close, etc.</remarks>  public static DataSet ExecuteDataset(SQLiteTransaction transaction, string commandText, object[] commandParameters)  {   if (transaction == null) throw new ArgumentNullException("transaction");   if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rolled back or committed,               please provide an open transaction.", "transaction");   IDbCommand cmd = transaction.Connection.CreateCommand();   cmd.CommandText = commandText;   AttachParameters((SQLiteCommand)cmd,cmd.CommandText, commandParameters);   if (transaction.Connection.State == ConnectionState.Closed)    transaction.Connection.Open();   DataSet ds = ExecuteDataset((SQLiteCommand)cmd);   return ds;  }  #region UpdateDataset  /// <summary>  /// Executes the respective command for each inserted, updated, or deleted row in the DataSet.  /// </summary>  /// <remarks>  /// e.g.:   /// UpdateDataset(conn, insertCommand, deleteCommand, updateCommand, dataSet, "Order");  /// </remarks>  /// <param name="insertCommand">A valid SQL statement to insert new records into the data source</param>  /// <param name="deleteCommand">A valid SQL statement to delete records from the data source</param>  /// <param name="updateCommand">A valid SQL statement used to update records in the data source</param>  /// <param name="dataSet">The DataSet used to update the data source</param>  /// <param name="tableName">The DataTable used to update the data source.</param>  public static void UpdateDataset(SQLiteCommand insertCommand, SQLiteCommand deleteCommand, SQLiteCommand updateCommand, DataSet dataSet, string tableName)  {   if (insertCommand == null) throw new ArgumentNullException("insertCommand");   if (deleteCommand == null) throw new ArgumentNullException("deleteCommand");   if (updateCommand == null) throw new ArgumentNullException("updateCommand");   if (tableName == null || tableName.Length == 0) throw new ArgumentNullException("tableName");   // Create a SQLiteDataAdapter, and dispose of it after we are done   using (SQLiteDataAdapter dataAdapter = new SQLiteDataAdapter())   {    // Set the data adapter commands    dataAdapter.UpdateCommand = updateCommand;    dataAdapter.InsertCommand = insertCommand;    dataAdapter.DeleteCommand = deleteCommand;    // Update the dataset changes in the data source    dataAdapter.Update(dataSet, tableName);    // Commit all the changes made to the DataSet    dataSet.AcceptChanges();   }  }  #endregion  /// <summary>  /// ShortCut method to return IDataReader  /// NOTE: You should explicitly close the Command.connection you passed in as  /// well as call Dispose on the Command after reader is closed.  /// We do this because IDataReader has no underlying Connection Property.  /// </summary>  /// <param name="cmd">SQLiteCommand Object</param>  /// <param name="commandText">SQL Statement with optional embedded "@param" style parameters</param>  /// <param name="paramList">object[] array of parameter values</param>  /// <returns>IDataReader</returns>  public static IDataReader ExecuteReader(SQLiteCommand cmd, string commandText, object[] paramList)  {   if (cmd.Connection == null)    throw new ArgumentException("Command must have live connection attached.", "cmd");   cmd.CommandText = commandText;   AttachParameters(cmd,commandText, paramList);   if (cmd.Connection.State == ConnectionState.Closed)    cmd.Connection.Open();   IDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);   return rdr;  }  /// <summary>  /// Shortcut to ExecuteNonQuery with SqlStatement and object[] param values  /// </summary>  /// <param name="connectionString">SQLite Connection String</param>  /// <param name="commandText">Sql Statement with embedded "@param" style parameters</param>  /// <param name="paramList">object[] array of parameter values</param>  /// <returns></returns>  public static int ExecuteNonQuery(string connectionString, string commandText, params object[] paramList)  {   SQLiteConnection cn = new SQLiteConnection(connectionString);   SQLiteCommand cmd = cn.CreateCommand();   cmd.CommandText = commandText;   AttachParameters(cmd,commandText, paramList);   if (cn.State == ConnectionState.Closed)    cn.Open();   int result = cmd.ExecuteNonQuery();   cmd.Dispose();   cn.Close();   return result;  }  public static int ExecuteNonQuery(SQLiteConnection cn, string commandText, params object[] paramList)  {   SQLiteCommand cmd = cn.CreateCommand();   cmd.CommandText = commandText;   AttachParameters(cmd,commandText, paramList);   if (cn.State == ConnectionState.Closed)    cn.Open();   int result = cmd.ExecuteNonQuery();   cmd.Dispose();   cn.Close();   return result;  }  /// <summary>  /// Executes non-query sql Statment with Transaction  /// </summary>  /// <param name="transaction">SQLiteTransaction. Transaction consists of Connection, Transaction, /// and Command, all of which must be created prior to making this method call. </param>  /// <param name="commandText">Command text.</param>  /// <param name="paramList">Param list.</param>  /// <returns>Integer</returns>  /// <remarks>user must examine Transaction Object and handle transaction.connection .Close, etc.</remarks>  public static int ExecuteNonQuery(SQLiteTransaction transaction, string commandText, params object[] paramList)  {   if (transaction == null) throw new ArgumentNullException("transaction");   if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rolled back or committed,              please provide an open transaction.", "transaction");   IDbCommand cmd = transaction.Connection.CreateCommand();   cmd.CommandText = commandText;   AttachParameters((SQLiteCommand)cmd,cmd.CommandText, paramList);   if (transaction.Connection.State == ConnectionState.Closed)    transaction.Connection.Open();   int result = cmd.ExecuteNonQuery();   cmd.Dispose();   return result;  }  /// <summary>  /// Executes the non query.  /// </summary>  /// <param name="cmd">CMD.</param>  /// <returns></returns>  public static int ExecuteNonQuery(IDbCommand cmd)  {   if (cmd.Connection.State == ConnectionState.Closed)    cmd.Connection.Open();   int result = cmd.ExecuteNonQuery();   cmd.Connection.Close();   cmd.Dispose();   return result;  }  /// <summary>  /// Shortcut to ExecuteScalar with Sql Statement embedded params and object[] param values  /// </summary>  /// <param name="connectionString">SQLite Connection String</param>  /// <param name="commandText">SQL statment with embedded "@param" style parameters</param>  /// <param name="paramList">object[] array of param values</param>  /// <returns></returns>  public static object ExecuteScalar(string connectionString, string commandText, params object[] paramList)  {   SQLiteConnection cn = new SQLiteConnection(connectionString);   SQLiteCommand cmd = cn.CreateCommand();   cmd.CommandText = commandText;   AttachParameters(cmd,commandText, paramList);   if (cn.State == ConnectionState.Closed)    cn.Open();   object result = cmd.ExecuteScalar();   cmd.Dispose();   cn.Close();   return result;  }  /// <summary>  /// Execute XmlReader with complete Command  /// </summary>  /// <param name="command">SQLite Command</param>  /// <returns>XmlReader</returns>  public static XmlReader ExecuteXmlReader(IDbCommand command)  { // open the connection if necessary, but make sure we    // know to close it when we�re done.   if (command.Connection.State != ConnectionState.Open)   {    command.Connection.Open();   }   // get a data adapter    SQLiteDataAdapter da = new SQLiteDataAdapter((SQLiteCommand)command);   DataSet ds = new DataSet();   // fill the data set, and return the schema information   da.MissingSchemaAction = MissingSchemaAction.AddWithKey;   da.Fill(ds);   // convert our dataset to XML   StringReader stream = new StringReader(ds.GetXml());   command.Connection.Close();   // convert our stream of text to an XmlReader   return new XmlTextReader(stream);  }  /// <summary>  /// Parses parameter names from SQL Statement, assigns values from object array , /// and returns fully populated ParameterCollection.  /// </summary>  /// <param name="commandText">Sql Statement with "@param" style embedded parameters</param>  /// <param name="paramList">object[] array of parameter values</param>  /// <returns>SQLiteParameterCollection</returns>  /// <remarks>Status experimental. Regex appears to be handling most issues. Note that parameter object array must be in same ///order as parameter names appear in SQL statement.</remarks>  private static SQLiteParameterCollection AttachParameters(SQLiteCommand cmd, string commandText, params object[] paramList)  {   if (paramList == null || paramList.Length == 0) return null;   SQLiteParameterCollection coll = cmd.Parameters;   string parmString = commandText.Substring(commandText.IndexOf("@"));   // pre-process the string so always at least 1 space after a comma.   parmString = parmString.Replace(",", " ,");   // get the named parameters into a match collection   string pattern = @"(@)/S*(.*?)/b";   Regex ex = new Regex(pattern, RegexOptions.IgnoreCase);   MatchCollection mc = ex.Matches(parmString);   string[] paramNames = new string[mc.Count];   int i = 0;   foreach (Match m in mc)   {    paramNames[i] = m.Value;    i++;   }   // now let's type the parameters   int j = 0;   Type t = null;   foreach (object o in paramList)   {    t = o.GetType();    SQLiteParameter parm = new SQLiteParameter();    switch (t.ToString())    {     case ("DBNull"):     case ("Char"):     case ("SByte"):     case ("UInt16"):     case ("UInt32"):     case ("UInt64"):      throw new SystemException("Invalid data type");     case ("System.String"):      parm.DbType = DbType.String;      parm.ParameterName = paramNames[j];      parm.Value = (string)paramList[j];      coll.Add(parm);      break;     case ("System.Byte[]"):      parm.DbType = DbType.Binary;      parm.ParameterName = paramNames[j];      parm.Value = (byte[])paramList[j];      coll.Add(parm);      break;     case ("System.Int32"):      parm.DbType = DbType.Int32;      parm.ParameterName = paramNames[j];      parm.Value = (int)paramList[j];      coll.Add(parm);      break;     case ("System.Boolean"):      parm.DbType = DbType.Boolean;      parm.ParameterName = paramNames[j];      parm.Value = (bool)paramList[j];      coll.Add(parm);      break;     case ("System.DateTime"):      parm.DbType = DbType.DateTime;      parm.ParameterName = paramNames[j];      parm.Value = Convert.ToDateTime(paramList[j]);      coll.Add(parm);      break;     case ("System.Double"):      parm.DbType = DbType.Double;      parm.ParameterName = paramNames[j];      parm.Value = Convert.ToDouble(paramList[j]);      coll.Add(parm);      break;     case ("System.Decimal"):      parm.DbType = DbType.Decimal;      parm.ParameterName = paramNames[j];      parm.Value = Convert.ToDecimal(paramList[j]);      break;     case ("System.Guid"):      parm.DbType = DbType.Guid;      parm.ParameterName = paramNames[j];      parm.Value = (System.Guid)(paramList[j]);      break;     case ("System.Object"):      parm.DbType = DbType.Object;      parm.ParameterName = paramNames[j];      parm.Value = paramList[j];      coll.Add(parm);      break;     default:      throw new SystemException("Value is of unknown data type");    } // end switch    j++;   }   return coll;  }  /// <summary>  /// Executes non query typed params from a DataRow  /// </summary>  /// <param name="command">Command.</param>  /// <param name="dataRow">Data row.</param>  /// <returns>Integer result code</returns>  public static int ExecuteNonQueryTypedParams(IDbCommand command, DataRow dataRow)  {   int retVal = 0;   // If the row has values, the store procedure parameters must be initialized   if (dataRow != null && dataRow.ItemArray.Length > 0)   {    // Set the parameters values    AssignParameterValues(command.Parameters, dataRow);    retVal = ExecuteNonQuery(command);   }   else   {    retVal = ExecuteNonQuery(command);   }   return retVal;  }  /// <summary>  /// This method assigns dataRow column values to an IDataParameterCollection  /// </summary>  /// <param name="commandParameters">The IDataParameterCollection to be assigned values</param>  /// <param name="dataRow">The dataRow used to hold the command's parameter values</param>  /// <exception cref="System.InvalidOperationException">Thrown if any of the parameter names are invalid.</exception>  protected internal static void AssignParameterValues(IDataParameterCollection commandParameters, DataRow dataRow)  {   if (commandParameters == null || dataRow == null)   {    // Do nothing if we get no data    return;   }   DataColumnCollection columns = dataRow.Table.Columns;   int i = 0;   // Set the parameters values   foreach (IDataParameter commandParameter in commandParameters)   {    // Check the parameter name    if (commandParameter.ParameterName == null ||     commandParameter.ParameterName.Length <= 1)     throw new InvalidOperationException(string.Format(       "Please provide a valid parameter name on the parameter #{0},       the ParameterName property has the following value: '{1}'.",      i, commandParameter.ParameterName));    if (columns.Contains(commandParameter.ParameterName))     commandParameter.Value = dataRow[commandParameter.ParameterName];    else if (columns.Contains(commandParameter.ParameterName.Substring(1)))     commandParameter.Value = dataRow[commandParameter.ParameterName.Substring(1)];    i++;   }  }  /// <summary>  /// This method assigns dataRow column values to an array of IDataParameters  /// </summary>  /// <param name="commandParameters">Array of IDataParameters to be assigned values</param>  /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values</param>  /// <exception cref="System.InvalidOperationException">Thrown if any of the parameter names are invalid.</exception>  protected void AssignParameterValues(IDataParameter[] commandParameters, DataRow dataRow)  {   if ((commandParameters == null) || (dataRow == null))   {    // Do nothing if we get no data    return;   }   DataColumnCollection columns = dataRow.Table.Columns;   int i = 0;   // Set the parameters values   foreach (IDataParameter commandParameter in commandParameters)   {    // Check the parameter name    if (commandParameter.ParameterName == null ||     commandParameter.ParameterName.Length <= 1)     throw new InvalidOperationException(string.Format(      "Please provide a valid parameter name on the parameter #{0}, the ParameterName property has the following value: '{1}'.",      i, commandParameter.ParameterName));    if (columns.Contains(commandParameter.ParameterName))     commandParameter.Value = dataRow[commandParameter.ParameterName];    else if (columns.Contains(commandParameter.ParameterName.Substring(1)))     commandParameter.Value = dataRow[commandParameter.ParameterName.Substring(1)];    i++;   }  }  /// <summary>  /// This method assigns an array of values to an array of IDataParameters  /// </summary>  /// <param name="commandParameters">Array of IDataParameters to be assigned values</param>  /// <param name="parameterValues">Array of objects holding the values to be assigned</param>  /// <exception cref="System.ArgumentException">Thrown if an incorrect number of parameters are passed.</exception>  protected void AssignParameterValues(IDataParameter[] commandParameters, params object[] parameterValues)  {   if ((commandParameters == null) || (parameterValues == null))   {    // Do nothing if we get no data    return;   }   // We must have the same number of values as we pave parameters to put them in   if (commandParameters.Length != parameterValues.Length)   {    throw new ArgumentException("Parameter count does not match Parameter Value count.");   }   // Iterate through the IDataParameters, assigning the values from the corresponding position in the    // value array   for (int i = 0, j = commandParameters.Length, k = 0; i < j; i++)   {    if (commandParameters[i].Direction != ParameterDirection.ReturnValue)    {     // If the current array value derives from IDataParameter, then assign its Value property     if (parameterValues[k] is IDataParameter)     {      IDataParameter paramInstance;      paramInstance = (IDataParameter)parameterValues[k];      if (paramInstance.Direction == ParameterDirection.ReturnValue)      {       paramInstance = (IDataParameter)parameterValues[++k];      }      if (paramInstance.Value == null)      {       commandParameters[i].Value = DBNull.Value;      }      else      {       commandParameters[i].Value = paramInstance.Value;      }     }     else if (parameterValues[k] == null)     {      commandParameters[i].Value = DBNull.Value;     }     else     {      commandParameters[i].Value = parameterValues[k];     }     k++;    }   }  } }}