[csharp] view plaincopy
- 首先:添加配置<add key="SQLString" value="~\demo.db"/>
[csharp] view plaincopy
[csharp] view plaincopy
- /**************************************
- * 作用:SQLLite Server操作实现
- **************************************/
- using System;
- using System.Collections;
- using System.Collections.Specialized;
- using System.Data;
- using System.Data.SQLite;//这个可以去网上下载
- using System.Configuration;
- public class SQLiteHelper
- {
- //数据库连接字符串(web.config来配置),可以动态更改SQLString支持多数据库.
- public static string connectionString = "Data Source=" + System.Web.HttpContext.Current.Server.MapPath(ConfigurationManager.AppSettings["SQLString"]);
- public SQLiteHelper() { }
- #region 公用方法
- public static int GetMaxID(string FieldName, string TableName)
- {
- string strsql = "select max(" + FieldName + ")+1 from " + TableName;
- object obj = GetSingle(strsql);
- if (obj == null)
- {
- return 1;
- }
- else
- {
- return int.Parse(obj.ToString());
- }
- }
- public static bool Exists(string strSql)
- {
- object obj = GetSingle(strSql);
- int cmdresult;
- if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
- {
- cmdresult = 0;
- }
- else
- {
- cmdresult = int.Parse(obj.ToString());
- }
- if (cmdresult == 0)
- {
- return false;
- }
- else
- {
- return true;
- }
- }
- public static bool Exists(string strSql, params SQLiteParameter[] cmdParms)
- {
- object obj = GetSingle(strSql, cmdParms);
- int cmdresult;
- if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
- {
- cmdresult = 0;
- }
- else
- {
- cmdresult = int.Parse(obj.ToString());
- }
- if (cmdresult == 0)
- {
- return false;
- }
- else
- {
- return true;
- }
- }
- #endregion
- #region 执行简单SQL语句
- /// <summary>
- /// 执行SQL语句,返回影响的记录数
- /// </summary>
- /// <param name="SQLString">SQL语句</param>
- /// <returns>影响的记录数</returns>
- public static int ExecuteSql(string SQLString)
- {
- using (SQLiteConnection connection = new SQLiteConnection(connectionString))
- {
- using (SQLiteCommand cmd = new SQLiteCommand(SQLString, connection))
- {
- try
- {
- connection.Open();
- int rows = cmd.ExecuteNonQuery();
- return rows;
- }
- catch (System.Data.SQLite.SQLiteException E)
- {
- connection.Close();
- throw new Exception(E.Message);
- }
- }
- }
- }
- /// <summary>
- /// 执行SQL语句,设置命令的执行等待时间
- /// </summary>
- /// <param name="SQLString"></param>
- /// <param name="Times"></param>
- /// <returns></returns>
- public static int ExecuteSqlByTime(string SQLString, int Times)
- {
- using (SQLiteConnection connection = new SQLiteConnection(connectionString))
- {
- using (SQLiteCommand cmd = new SQLiteCommand(SQLString, connection))
- {
- try
- {
- connection.Open();
- cmd.CommandTimeout = Times;
- int rows = cmd.ExecuteNonQuery();
- return rows;
- }
- catch (System.Data.SQLite.SQLiteException E)
- {
- connection.Close();
- throw new Exception(E.Message);
- }
- }
- }
- }
- /// <summary>
- /// 执行多条SQL语句,实现数据库事务。
- /// </summary>
- /// <param name="SQLStringList">多条SQL语句</param>
- public static void ExecuteSqlTran(ArrayList SQLStringList)
- {
- using (SQLiteConnection conn = new SQLiteConnection(connectionString))
- {
- conn.Open();
- SQLiteCommand cmd = new SQLiteCommand();
- cmd.Connection = conn;
- SQLiteTransaction tx = conn.BeginTransaction();
- cmd.Transaction = tx;
- try
- {
- for (int n = 0; n < SQLStringList.Count; n++)
- {
- string strsql = SQLStringList[n].ToString();
- if (strsql.Trim().Length > 1)
- {
- cmd.CommandText = strsql;
- cmd.ExecuteNonQuery();
- }
- }
- tx.Commit();
- }
- catch (System.Data.SQLite.SQLiteException E)
- {
- tx.Rollback();
- throw new Exception(E.Message);
- }
- }
- }
- /// <summary>
- /// 执行带一个存储过程参数的的SQL语句。
- /// </summary>
- /// <param name="SQLString">SQL语句</param>
- /// <param name="content">参数内容,比如一个字段是格式复杂的文章,有特殊符号,可以通过这个方式添加</param>
- /// <returns>影响的记录数</returns>
- public static int ExecuteSql(string SQLString, string content)
- {
- using (SQLiteConnection connection = new SQLiteConnection(connectionString))
- {
- SQLiteCommand cmd = new SQLiteCommand(SQLString, connection);
- SQLiteParameter myParameter = new SQLiteParameter("@content", DbType.String);
- myParameter.Value = content;
- cmd.Parameters.Add(myParameter);
- try
- {
- connection.Open();
- int rows = cmd.ExecuteNonQuery();
- return rows;
- }
- catch (System.Data.SQLite.SQLiteException E)
- {
- throw new Exception(E.Message);
- }
- finally
- {
- cmd.Dispose();
- connection.Close();
- }
- }
- }
- /// <summary>
- /// 执行带一个存储过程参数的的SQL语句。
- /// </summary>
- /// <param name="SQLString">SQL语句</param>
- /// <param name="content">参数内容,比如一个字段是格式复杂的文章,有特殊符号,可以通过这个方式添加</param>
- /// <returns>影响的记录数</returns>
- public static object ExecuteSqlGet(string SQLString, string content)
- {
- using (SQLiteConnection connection = new SQLiteConnection(connectionString))
- {
- SQLiteCommand cmd = new SQLiteCommand(SQLString, connection);
- SQLiteParameter myParameter = new SQLiteParameter("@content", DbType.String);
- myParameter.Value = content;
- cmd.Parameters.Add(myParameter);
- try
- {
- connection.Open();
- object obj = cmd.ExecuteScalar();
- if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
- {
- return null;
- }
- else
- {
- return obj;
- }
- }
- catch (System.Data.SQLite.SQLiteException E)
- {
- throw new Exception(E.Message);
- }
- finally
- {
- cmd.Dispose();
- connection.Close();
- }
- }
- }
- /// <summary>
- /// 向数据库里插入图像格式的字段(和上面情况类似的另一种实例)
- /// </summary>
- /// <param name="strSQL">SQL语句</param>
- /// <param name="fs">图像字节,数据库的字段类型为image的情况</param>
- /// <returns>影响的记录数</returns>
- public static int ExecuteSqlInsertImg(string strSQL, byte[] fs)
- {
- using (SQLiteConnection connection = new SQLiteConnection(connectionString))
- {
- SQLiteCommand cmd = new SQLiteCommand(strSQL, connection);
- SQLiteParameter myParameter = new SQLiteParameter("@fs", DbType.Binary);
- myParameter.Value = fs;
- cmd.Parameters.Add(myParameter);
- try
- {
- connection.Open();
- int rows = cmd.ExecuteNonQuery();
- return rows;
- }
- catch (System.Data.SQLite.SQLiteException E)
- {
- throw new Exception(E.Message);
- }
- finally
- {
- cmd.Dispose();
- connection.Close();
- }
- }
- }
- /// <summary>
- /// 执行一条计算查询结果语句,返回查询结果(object)。
- /// </summary>
- /// <param name="SQLString">计算查询结果语句</param>
- /// <returns>查询结果(object)</returns>
- public static object GetSingle(string SQLString)
- {
- using (SQLiteConnection connection = new SQLiteConnection(connectionString))
- {
- using (SQLiteCommand cmd = new SQLiteCommand(SQLString, connection))
- {
- try
- {
- connection.Open();
- object obj = cmd.ExecuteScalar();
- if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
- {
- return null;
- }
- else
- {
- return obj;
- }
- }
- catch (System.Data.SQLite.SQLiteException e)
- {
- connection.Close();
- throw new Exception(e.Message);
- }
- }
- }
- }
- /// <summary>
- /// 执行查询语句,返回SQLiteDataReader(使用该方法切记要手工关闭SQLiteDataReader和连接)
- /// </summary>
- /// <param name="strSQL">查询语句</param>
- /// <returns>SQLiteDataReader</returns>
- public static SQLiteDataReader ExecuteReader(string strSQL)
- {
- SQLiteConnection connection = new SQLiteConnection(connectionString);
- SQLiteCommand cmd = new SQLiteCommand(strSQL, connection);
- try
- {
- connection.Open();
- SQLiteDataReader myReader = cmd.ExecuteReader();
- return myReader;
- }
- catch (System.Data.SQLite.SQLiteException e)
- {
- throw new Exception(e.Message);
- }
- //finally //不能在此关闭,否则,返回的对象将无法使用
- //{
- // cmd.Dispose();
- // connection.Close();
- //}
- }
- /// <summary>
- /// 执行查询语句,返回DataSet
- /// </summary>
- /// <param name="SQLString">查询语句</param>
- /// <returns>DataSet</returns>
- public static DataSet Query(string SQLString)
- {
- using (SQLiteConnection connection = new SQLiteConnection(connectionString))
- {
- DataSet ds = new DataSet();
- try
- {
- connection.Open();
- SQLiteDataAdapter command = new SQLiteDataAdapter(SQLString, connection);
- command.Fill(ds, "ds");
- }
- catch (System.Data.SQLite.SQLiteException ex)
- {
- throw new Exception(ex.Message);
- }
- return ds;
- }
- }
- public static DataSet Query(string SQLString, string TableName)
- {
- using (SQLiteConnection connection = new SQLiteConnection(connectionString))
- {
- DataSet ds = new DataSet();
- try
- {
- connection.Open();
- SQLiteDataAdapter command = new SQLiteDataAdapter(SQLString, connection);
- command.Fill(ds, TableName);
- }
- catch (System.Data.SQLite.SQLiteException ex)
- {
- throw new Exception(ex.Message);
- }
- return ds;
- }
- }
- /// <summary>
- /// 执行查询语句,返回DataSet,设置命令的执行等待时间
- /// </summary>
- /// <param name="SQLString"></param>
- /// <param name="Times"></param>
- /// <returns></returns>
- public static DataSet Query(string SQLString, int Times)
- {
- using (SQLiteConnection connection = new SQLiteConnection(connectionString))
- {
- DataSet ds = new DataSet();
- try
- {
- connection.Open();
- SQLiteDataAdapter command = new SQLiteDataAdapter(SQLString, connection);
- command.SelectCommand.CommandTimeout = Times;
- command.Fill(ds, "ds");
- }
- catch (System.Data.SQLite.SQLiteException ex)
- {
- throw new Exception(ex.Message);
- }
- return ds;
- }
- }
- #endregion
- #region 执行带参数的SQL语句
- /// <summary>
- /// 执行SQL语句,返回影响的记录数
- /// </summary>
- /// <param name="SQLString">SQL语句</param>
- /// <returns>影响的记录数</returns>
- public static int ExecuteSql(string SQLString, params SQLiteParameter[] cmdParms)
- {
- using (SQLiteConnection connection = new SQLiteConnection(connectionString))
- {
- using (SQLiteCommand cmd = new SQLiteCommand())
- {
- try
- {
- PrepareCommand(cmd, connection, null, SQLString, cmdParms);
- int rows = cmd.ExecuteNonQuery();
- cmd.Parameters.Clear();
- return rows;
- }
- catch (System.Data.SQLite.SQLiteException E)
- {
- throw new Exception(E.Message);
- }
- }
- }
- }
- /// <summary>
- /// 执行多条SQL语句,实现数据库事务。
- /// </summary>
- /// <param name="SQLStringList">SQL语句的哈希表(key为sql语句,value是该语句的SQLiteParameter[])</param>
- public static void ExecuteSqlTran(Hashtable SQLStringList)
- {
- using (SQLiteConnection conn = new SQLiteConnection(connectionString))
- {
- conn.Open();
- using (SQLiteTransaction trans = conn.BeginTransaction())
- {
- SQLiteCommand cmd = new SQLiteCommand();
- try
- {
- //循环
- foreach (DictionaryEntry myDE in SQLStringList)
- {
- string cmdText = myDE.Key.ToString();
- SQLiteParameter[] cmdParms = (SQLiteParameter[]) myDE.Value;
- PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
- int val = cmd.ExecuteNonQuery();
- cmd.Parameters.Clear();
- trans.Commit();
- }
- }
- catch
- {
- trans.Rollback();
- throw;
- }
- }
- }
- }
- /// <summary>
- /// 执行一条计算查询结果语句,返回查询结果(object)。
- /// </summary>
- /// <param name="SQLString">计算查询结果语句</param>
- /// <returns>查询结果(object)</returns>
- public static object GetSingle(string SQLString, params SQLiteParameter[] cmdParms)
- {
- using (SQLiteConnection connection = new SQLiteConnection(connectionString))
- {
- using (SQLiteCommand cmd = new SQLiteCommand())
- {
- try
- {
- PrepareCommand(cmd, connection, null, SQLString, cmdParms);
- object obj = cmd.ExecuteScalar();
- cmd.Parameters.Clear();
- if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
- {
- return null;
- }
- else
- {
- return obj;
- }
- }
- catch (System.Data.SQLite.SQLiteException e)
- {
- throw new Exception(e.Message);
- }
- }
- }
- }
- /// <summary>
- /// 执行查询语句,返回SQLiteDataReader (使用该方法切记要手工关闭SQLiteDataReader和连接)
- /// </summary>
- /// <param name="strSQL">查询语句</param>
- /// <returns>SQLiteDataReader</returns>
- public static SQLiteDataReader ExecuteReader(string SQLString, params SQLiteParameter[] cmdParms)
- {
- SQLiteConnection connection = new SQLiteConnection(connectionString);
- SQLiteCommand cmd = new SQLiteCommand();
- try
- {
- PrepareCommand(cmd, connection, null, SQLString, cmdParms);
- SQLiteDataReader myReader = cmd.ExecuteReader();
- cmd.Parameters.Clear();
- return myReader;
- }
- catch (System.Data.SQLite.SQLiteException e)
- {
- throw new Exception(e.Message);
- }
- //finally //不能在此关闭,否则,返回的对象将无法使用
- //{
- // cmd.Dispose();
- // connection.Close();
- //}
- }
- /// <summary>
- /// 执行查询语句,返回DataSet
- /// </summary>
- /// <param name="SQLString">查询语句</param>
- /// <returns>DataSet</returns>
- public static DataSet Query(string SQLString, params SQLiteParameter[] cmdParms)
- {
- using (SQLiteConnection connection = new SQLiteConnection(connectionString))
- {
- SQLiteCommand cmd = new SQLiteCommand();
- PrepareCommand(cmd, connection, null, SQLString, cmdParms);
- using (SQLiteDataAdapter da = new SQLiteDataAdapter(cmd))
- {
- DataSet ds = new DataSet();
- try
- {
- da.Fill(ds, "ds");
- cmd.Parameters.Clear();
- }
- catch (System.Data.SQLite.SQLiteException ex)
- {
- throw new Exception(ex.Message);
- }
- return ds;
- }
- }
- }
- public static void PrepareCommand(SQLiteCommand cmd, SQLiteConnection conn, SQLiteTransaction trans, string cmdText, SQLiteParameter[] cmdParms)
- {
- if (conn.State != ConnectionState.Open)
- conn.Open();
- cmd.Connection = conn;
- cmd.CommandText = cmdText;
- if (trans != null)
- cmd.Transaction = trans;
- cmd.CommandType = CommandType.Text;//cmdType;
- if (cmdParms != null)
- {
- foreach (SQLiteParameter parameter in cmdParms)
- {
- if ((parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input) &&
- (parameter.Value == null))
- {
- parameter.Value = DBNull.Value;
- }
- cmd.Parameters.Add(parameter);
- }
- }
- }
- #endregion
- #region 参数转换
- /// <summary>
- /// 放回一个SQLiteParameter
- /// </summary>
- /// <param name="name">参数名字</param>
- /// <param name="type">参数类型</param>
- /// <param name="size">参数大小</param>
- /// <param name="value">参数值</param>
- /// <returns>SQLiteParameter的值</returns>
- public static SQLiteParameter MakeSQLiteParameter(string name, DbType type, int size, object value)
- {
- SQLiteParameter parm = new SQLiteParameter(name, type, size);
- parm.Value = value;
- return parm;
- }
- public static SQLiteParameter MakeSQLiteParameter(string name, DbType type, object value)
- {
- SQLiteParameter parm = new SQLiteParameter(name, type);
- parm.Value = value;
- return parm;
- }
- #endregion
- }
调用方法
[csharp] view plaincopy
- /// <summary>
- /// 判断用户是否存在
- /// </summary>
- /// <param name="name">用户名称</param>
- /// <returns></returns>
- public bool UserExists(string name)
- {
- StringBuilder strSql = new StringBuilder();
- strSql.Append("select count(*) n from Users");
- strSql.Append(" where [email protected] ");
- SQLiteParameter[] parameters = {
- SQLiteHelper.MakeSQLiteParameter("@UserName", DbType.String,30,name)};
- return SQLiteHelper.Exists(strSql.ToString(), parameters);
- }
- /// <summary>
- /// 增加一个用户
- /// </summary>
- /// <param name="name">用户名</param>
- /// <param name="pwd">密码</param>
- /// <returns></returns>
- public int CreateUser(string name, string pwd)
- {
- int ret = 0;
- if (!UserExists(name))
- {
- StringBuilder strSql = new StringBuilder();
- strSql.Append("insert into t_UserGroup(");
- strSql.Append("UserName,Password)");
- strSql.Append(" values (");
- strSql.Append("@UserName,@Password)");
- SQLiteParameter[] parameters = {
- SQLiteHelper.MakeSQLiteParameter("@UserName", DbType.String,30,name),
- SQLiteHelper.MakeSQLiteParameter("@Password", DbType.String,128,pwd)
- };
- if (SQLiteHelper.ExecuteSql(strSql.ToString(), parameters) >= 1)
- {
- ret = 1;
- }
- }
- else
- {
- ret = 2;
- }
- return ret;
- }
- /// <summary>
- /// 更新一条数据
- /// </summary>
- /// <param name="model">用户分组实体类</param>
- /// <returns></returns>
- public bool UpdateUser(int id, string name, string pwd)
- {
- StringBuilder strSql = new StringBuilder();
- strSql.Append("update Users set ");
- strSql.Append("[email protected],");
- strSql.Append("[email protected]");
- strSql.Append(" where [email protected]");
- SQLiteParameter[] parameters = {
- SQLiteHelper.MakeSQLiteParameter("@UserID", DbType.Int32,11,id),
- SQLiteHelper.MakeSQLiteParameter("@UserName", DbType.String,30,name),
- SQLiteHelper.MakeSQLiteParameter("@Password", DbType.String,128,pwd)};
- if (SQLiteHelper.ExecuteSql(strSql.ToString(), parameters) >= 1)
- {
- return true;
- }
- else
- {
- return false;
- }
- }
- /// <summary>
- /// 删除用户
- /// </summary>
- /// <param name="ID">用户ID</param>
- /// <returns></returns>
- public int DeleteUser(int id)
- {
- int ret = 0;
- string strSql3 = "delete from Users where [email protected]";
- SQLiteParameter[] parameters = {
- SQLiteHelper.MakeSQLiteParameter("@UserID", DbType.Int32,4,id)};
- if (SQLiteHelper.ExecuteSql(strSql3, parameters) >= 1)
- {
- ret = 1;
- }
- else
- {
- ret = 0;
- }
- return ret;
- }
- /// <summary>
- /// 获得用户分组数据列表
- /// </summary>
- /// <param name="strWhere">Where条件</param>
- /// <returns></returns>
- public DataSet GetUserList(string strWhere)
- {
- StringBuilder strSql = new StringBuilder();
- strSql.Append("select * FROM Users ");
- if (strWhere.Trim() != "")
- {
- strSql.Append(" where " + strWhere);
- }
- strSql.Append(" order by UserID desc");
- return SQLiteHelper.Query(strSql.ToString());
- }
注意事项
1. @@IDENTITY LAST_INSERT_ROWID()
2. SELECT cn = COUNT(*) FROM ... SELECT COUNT(*) cn FROM ...
3. LIMIT startIndex,itemCn 这儿的startIndex是从0开始的,而ROW_NUMBER()是从1开始的
4. sqlite中没有SELECT TOP,用LIMIT即可
5. SQLite自增字段,如果在事务中插入数据失败,并不会占用增长后的id,而sql server中对应的id将无效
6. SQLite中没有GETDATE日期函数,在类中加入参数如下DbType.DateTime,DateTime.Now.ToString("s")
7. SQLite支持REPLACE INTO语法,sql server 2008中支持merge to
转载自http://blog.csdn.net/kingboy2008/article/details/6752898
时间: 2024-11-09 00:46:24