C#基于SQLiteHelper类似SqlHelper类实现存取Sqlite数据库的方法

本文实例讲述了C#基于SQLiteHelper类似SqlHelper类实现存取Sqlite数据库的方法。分享给大家供大家参考。具体如下：

这个类不是我实现的，英文原文地址为http://www.eggheadcafe.com/articles/20050315.asp，这里修改了原文中分析sql语句参数的方法，将方法名修改为AttachParameters，将其修饰符修改为private，并直接传递command到这个方法，直接绑定参数到comand。修改后的代码如下

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++;
   }
  }
 }
}
}

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