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C#操作SQLite数据库方法小结(创建,连接,插入,查询,删除等)

时间:2020-10-24 11:49:48|栏目:.NET代码|点击:

本文实例讲述了C#操作SQLite数据库方法。分享给大家供大家参考,具体如下:

SQLite介绍

SQLite is a software library that implements a self-contained, serverless, zero-configuration, transactional SQL database engine.

SQLite是一个开源、免费的小型RDBMS(关系型数据库),能独立运行、无服务器、零配置、支持事物,用C实现,内存占用较小,支持绝大数的SQL92标准。

SQLite数据库官方主页:http://www.sqlite.org/index.html

C#操作SQLite Database

C#下SQLite操作驱动dll下载:System.Data.SQLite

C#使用SQLite步骤:

(1)新建一个project
(2)添加SQLite操作驱动dll引用
(3)使用API操作SQLite DataBase

using System;
using System.Data.SQLite;
namespace SQLiteSamples
{
  class Program
  {
    //数据库连接
    SQLiteConnection m_dbConnection;
    static void Main(string[] args)
    {
      Program p = new Program();
    }
    public Program()
    {
      createNewDatabase();
      connectToDatabase();
      createTable();
      fillTable();
      printHighscores();
    }
    //创建一个空的数据库
    void createNewDatabase()
    {
      SQLiteConnection.CreateFile("MyDatabase.sqlite");
    }
    //创建一个连接到指定数据库
    void connectToDatabase()
    {
      m_dbConnection = new SQLiteConnection("Data Source=MyDatabase.sqlite;Version=3;");
      m_dbConnection.Open();
    }
    //在指定数据库中创建一个table
    void createTable()
    {
      string sql = "create table highscores (name varchar(20), score int)";
      SQLiteCommand command = new SQLiteCommand(sql, m_dbConnection);
      command.ExecuteNonQuery();
    }
    //插入一些数据
    void fillTable()
    {
      string sql = "insert into highscores (name, score) values ('Me', 3000)";
      SQLiteCommand command = new SQLiteCommand(sql, m_dbConnection);
      command.ExecuteNonQuery();
      sql = "insert into highscores (name, score) values ('Myself', 6000)";
      command = new SQLiteCommand(sql, m_dbConnection);
      command.ExecuteNonQuery();
      sql = "insert into highscores (name, score) values ('And I', 9001)";
      command = new SQLiteCommand(sql, m_dbConnection);
      command.ExecuteNonQuery();
    }
    //使用sql查询语句,并显示结果
    void printHighscores()
    {
      string sql = "select * from highscores order by score desc";
      SQLiteCommand command = new SQLiteCommand(sql, m_dbConnection);
      SQLiteDataReader reader = command.ExecuteReader();
      while (reader.Read())
        Console.WriteLine("Name: " + reader["name"] + "\tScore: " + reader["score"]);
      Console.ReadLine();
    }
  }
}

关于SQLite的connection string说明:http://www.connectionstrings.com/sqlite/

SQLite GUI客户端列表:http://www.sqlite.org/cvstrac/wiki?p=ManagementTools

SQLite Administrator下载地址:http://download.orbmu2k.de/files/sqliteadmin.zip

操作SQLite Database的C#帮助类SQLite Helper

将一些常用的功能封装一下,封装成SQLite Helper类

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++;
        }
      }
    }
  }
}

Codeproject上的一个封装:http://www.codeproject.com/Articles/746191/SQLite-Helper-Csharp

更多关于C#相关内容感兴趣的读者可查看本站专题:《C#程序设计之线程使用技巧总结》、《C#操作Excel技巧总结》、《C#中XML文件操作技巧汇总》、《C#常见控件用法教程》、《WinForm控件用法总结》、《C#数据结构与算法教程》、《C#数组操作技巧总结》及《C#面向对象程序设计入门教程

希望本文所述对大家C#程序设计有所帮助。

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