1. ADO.NET Provider For SQLite. ADO.NET 提供程序是香港(貌似)一个公司提供的.项目地址见:http://sourceforge.net/projects/sqlite-dotnet2 2. 对SQLite.NET的封装,提供一个简单的操作帮助类. SQLiteHelper 复制代码 代码如下: /**//** * SQLite操作的帮助类. * * Author: egmkang.wang * Date: 2009-06-21 */ namespace System.Data.SQLite { using System.Data; using System.Data.SQLite; using System.IO; public class SqliteHelper { private static string pwd = "PWD"; private static string path = Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase) + "\\sqliteTest.db"; private static string connString = string.Format("Data Source =\"{0}\"", path, pwd); /**//// <summary> /// 返回数据库链接字符串 /// </summary> public static string ConnString { get { return connString; } } /**//// <summary> /// 执行SQL语句,返回受影响的行数 /// </summary> /// <param name="cmdText">需要被执行的SQL语句</param> /// <returns>受影响的行数</returns> public static int ExecuteNonQuery(string cmdText) { return ExecuteNonQuery(ConnString, cmdText); } /**//// <summary> /// 执行带有事务的SQL语句 /// </summary> /// <param name="trans">事务</param> /// <param name="cmdText">SQL语句</param> /// <returns>受影响的行数</returns> public static int ExecuteNonQuery(SQLiteTransaction trans, string cmdText, params SQLiteParameter[] parameters) { int val = 0; using (SQLiteCommand cmd = new SQLiteCommand()) { PrepareCommand(cmd, (SQLiteConnection)trans.Connection, trans, cmdText, parameters); val = cmd.ExecuteNonQuery(); cmd.Parameters.Clear(); } return val; } /**//// <summary> /// 执行SQL语句,返回受影响的行数 /// </summary> /// <param name="connString">连接字符串</param> /// <param name="cmdText">SQL语句</param> /// <param name="parameters">SQL的参数</param> /// <returns>受影响的行数</returns> public static int ExecuteNonQuery(string connString, string cmdText, params SQLiteParameter[] parameters) { using (SQLiteConnection conn = new SQLiteConnection(connString)) { return ExecuteNonQuery(conn, cmdText, parameters); } } /**//// <summary> /// 执行SQL语句,返回受影响的行数 /// </summary> /// <param name="connection">数据库链接</param> /// <param name="cmdText">SQL语句</param> /// <param name="parameters">参数</param> /// <returns>受影响的行数</returns> public static int ExecuteNonQuery(SQLiteConnection connection, string cmdText, params SQLiteParameter[] parameters) { int val = 0; using (SQLiteCommand cmd = new SQLiteCommand()) { PrepareCommand(cmd, connection, null, cmdText, parameters); val = cmd.ExecuteNonQuery(); cmd.Parameters.Clear(); } return val; } /**//// <summary> /// 执行查询,并返回结果集的第一行的第一列.其他所有的行和列被忽略. /// </summary> /// <param name="cmdText">SQL 语句</param> /// <returns>第一行的第一列的值</returns> public static object ExecuteScalar(string cmdText) { return ExecuteScalar(ConnString, cmdText); } /**//// <summary> /// 执行查询,并返回结果集的第一行的第一列.wjeoXpgLG其他所有的行和列被忽略. /// </summary> /// <param name="connString">连接字符串</param> /// <param name="cmdText">SQL 语句</param> /// <returns>第一行的第一列的值</returns> public static object ExecuteScalar(string connString, string cmdText) { using (SQLiteConnection conn = new SQLiteConnection(connString)) { return ExecuteScalar(conn, cmdText); } } /**//// <summary> /// 执行查询,并返回结果集的第一行的第一列.其他所有的行和列被忽略. /// </summary> /// <param name="connection">数据库链接</param> /// <param name="cmdText">SQL 语句</param> /// <returns>第一行的第一列的值</returns> public static object ExecuteScalar(SQLiteConnection connection, string cmdText) { object val; using (SQLiteCommand cmd = new SQLiteCommand()) { PrepareCommand(cmd, connection, null, cmdText); val = cmd.ExecuteScalar(); } return val; } /**//// <summary> /// 执行SQL语句,返回结果集的DataReader /// </summaryhttp://www.devze.com> /// <param name="cmdText">SQL语句</param> /// <param name="parameters">参数</param> /// <returns>结果集的DataReader</returns> public static SQLiteDataReader ExecuteReader(string cmdText, params SQLiteParameter[] parameters) { return ExecuteReader(ConnString, cmdText, parameters); } /**//// <summary> /// 执行SQL语句,返回结果集的DataReader /// </summary> /// <param name="connString">连接字符串</param> /// <param name="cmdText">SQL语句</param> /// <param name="parameters">参数</param> /// <returns>结果集的DataReader</returns> public static SQLiteDataReader ExecuteReader(strin编程客栈g connString, string cmdText, params SQLiteParameter[] parameters) { SQLiteConnection conn = new SQLiteConnection(connString); SQLiteCommand cmd = new SQLiteCommand(); try { PrepareCommand(cmd, conn, null, cmdText, parameters); SQLiteDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection); cmd.Parameters.Clear(); return rdr; } catch { conn.Close(); throw; } } /**//// <summary> /// 预处理Command对象,数据库链接,事务,需要执行的对象,参数等的初始化 /// </summary> /// <param name="cmd">Command对象</param> /// <param name="conn">Connection对象</param> /// <param name="trans">Transcation对象</param> /// <param name="cmdText">SQL Text</param> /// <param name="parameters">参数实例</param> private static void PrepareCommand(SQLiteCommand cmd, SQLiteConnection conn, SQLiteTransaction trans, string cmdText, params SQLiteParameter[] parameters) { if (conn.State != ConnectionState.Open) conn.Open(); cmd.Connection = conn; cmd.CommandText = cmdText; if (trans != null) cmd.Transaction = trans; if (null != parameters && parameters.Length > 0) { cmd.Parameters.AddRange(parameters); } } } } 3. 增删改查: 复制代码 代码如下: Insert,Delete,Update const string s_AddressTreeIntoSQLite = "Insert into [AddressTree] ([Id],[ItemType],[ParentId],[Name]) values (@Id,@ItemType,@ParentId,@Name);"; SqliteHelper.ExecuteNonQuery(tran, s_AddressTreeIntoSQLite, //new SQLi编程客栈teParameter[] here ); Select const string s_AddresTreeFromSqlCE = "Select [Id],[ItemType],[ParentId],[Name] From [AddressTree];"; using (SqlCeDataReader rdr = SqlCeHelper.ExecuteReader(s_AddresTreeFromSqlCE )) { while (rdr.Read()) { //Readhttp://www.devze.com Data Here } } 4. 其他 SQLite性能绝对强悍.四表连接查询,查询200次,SQL CE需要44秒(with index),SQLite只需要3-6秒(with index). 插入,删除更新性能参见http://www.cnblogs.com/egmkang/archive/2009/06/06/1497678.html PS:最近发现执行sql的时候,最好使用单一的长连接,而不是ConnectionString.原因很简单,嵌入式数据库没有连接池技术, 在进行数据库查询中的链接的打开关闭费用相对来说比较高昂.这一点在写程序的时候注意以下. 还有,有关二进制资源,需要及时释放,例如SqlCommand,这些在写Web 程开发者_数据库教程序的时候体验不是很大,毕竟那种环境拥有大量 的内存,GC的效率又是比较高.
Sqlite 操作类代码
1. ADO.NET Provider For SQLite. ADO.NET 提供程序是香港(貌似)一个公司提供的.项目地址见:http://sourceforge.net/projects/sqlite-dotnet2 2. 对SQLite.NET的封装,提供一个简单的操作帮助类. SQLiteHelpe
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