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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)

作者:阿凡卢  发布时间:2024-01-23 01:06:29 

标签:C#,SQLite

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

希望本文所述对大家C#程序设计有所帮助。

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