ASP.NET对SQLServer的通用数据库访问类

/// <summary> /// 数据库访问通用类 /// </summary> public class SqlHelper { private string connectionString; /// <summary> /// 设定数据库访问字符串 /// </summary> public string ConnectionString { set { connectionString = value; } } /// <summary> /// 构造函数 /// </summary> /// <param>数据库访问字符串</param> public SqlHelper(string connectionString) { this.connectionString = connectionString; } /// <summary> /// 执行一个查询，并返回查询结果 /// </summary> /// <param>要执行的sql语句</param> /// <param>要执行的查询语句的类型，如存储过程或者sql文本命令</param> /// <returns>返回查询结果集</returns> public DataTable ExecuteDataTable(string sql,CommandType commandType) { return ExecuteDataTable(sql, commandType, null); } /// <summary> /// 执行一个查询，并返回结果集 /// </summary> /// <param>要执行的sql文本命令</param> /// <returns>返回查询的结果集</returns> public DataTable ExecuteDataTable(string sql) { return ExecuteDataTable(sql, CommandType.Text, null); } /// <summary> /// 执行一个查询，并返回查询结果 /// </summary> /// <param>要执行的sql语句</param> /// <param>要执行查询语句的类型，如存储过程或者sql文本命令</param> /// <param>Transact-SQL语句或者存储过程参数数组</param> /// <returns></returns> public DataTable ExecuteDataTable(string sql, CommandType commandtype, SqlParameter[] parameters) { DataTable data = new DataTable(); //实例化datatable，用于装载查询结果集 using (SqlConnection con = new SqlConnection(connectionString)) { using (SqlCommand cmd = new SqlCommand(sql, con)) { cmd.CommandType = commandtype;//设置command的commandType为指定的Commandtype //如果同时传入了参数，则添加这些参数 if (parameters != null) { foreach (SqlParameter parameter in parameters) { cmd.Parameters.Add(parameter); } } //通过包含查询sql的sqlcommand实例来实例化sqldataadapter SqlDataAdapter adapter = new SqlDataAdapter(cmd); adapter.Fill(data);//填充datatable } } return data; } /// <summary> /// 返回一个SqlDataReader对象的实例 /// </summary> /// <param>要执行的SQl查询命令</param> /// <returns></returns> public SqlDataReader ExecuteReader(string sql) { return ExecuteReader(sql, CommandType.Text, null); } /// <summary> /// /// </summary> /// <param>要执行的sql语句</param> /// <param>要执行查询语句的类型，如存储过程或者SQl文本命令</param> /// <returns></returns> public SqlDataReader ExecuteReader(string sql,CommandType commandType) { return ExecuteReader(sql, commandType, null); } /// <summary> /// 返回一个sqldatareader对象的实例 /// </summary> /// <param></param> /// <param></param> /// <param></param> /// <returns></returns> public SqlDataReader ExecuteReader(string sql, CommandType commandType, SqlParameter[] parameters) { SqlConnection con = new SqlConnection(connectionString); SqlCommand cmd = new SqlCommand(sql, con); if (parameters != null) { foreach (SqlParameter parameter in parameters) { cmd.Parameters.Add(parameters); } } con.Open(); //CommandBehavior.CloseConnection参数指示关闭reader对象时关闭与其关联的Connection对象 return cmd.ExecuteReader(CommandBehavior.CloseConnection); } /// <summary> /// 执行一个查询，返回结果集的首行首列。忽略其他行，其他列 /// </summary> /// <param>要执行的SQl命令</param> /// <returns></returns> public Object ExecuteScalar(string sql) { return ExecuteScalar(sql, CommandType.Text, null); } /// <summary> /// /// </summary> /// <param></param> /// <param></param> /// <returns></returns> public Object ExecuteScalar(string sql, CommandType commandType) { return ExecuteScalar(sql, commandType, null); } /// <summary> /// /// </summary> /// <param></param> /// <param>参数类型</param> /// <param></param> /// <returns></returns> public Object ExecuteScalar(string sql,CommandType commandType, SqlParameter[] parameters) { Object result=null; SqlConnection con=new SqlConnection(connectionString); SqlCommand cmd=new SqlCommand(sql,con); cmd.CommandType= commandType; if(parameters!=null) { foreach (SqlParameter parapmeter in parameters) { cmd.Parameters.Add(parapmeter); } } con.Open(); result=cmd.ExecuteScalar(); con.Close(); return result; } /// <summary> /// 对数据库进行增删改的操作 /// </summary> /// <param>要执行的sql命令</param> /// <returns></returns> public int ExecuteNonQuery(string sql) { return ExecuteNonQuery(sql, CommandType.Text, null); } /// <summary> /// 数据库进行增删改的操作 /// </summary> /// <param>对数据库进行操作的sql命令</param> /// <param>要执行查询语句的类型，如存储过程或者sql文本命令</param> /// <returns></returns> public int ExecuteNonQuery(string sql, CommandType commandType) { return ExecuteNonQuery(sql, commandType, null); } /// <summary> /// 对数据库进行增删改的操作 /// </summary> /// <param>要执行的sql语句</param> /// <param>要执行的查询语句类型，如存储过程或者sql文本命令</param> /// <param>Transact-SQL语句或者存储过程的参数数组</param> /// <returns></returns> public int ExecuteNonQuery(string sql, CommandType commandType, SqlParameter[] parameters) { int count = 0; SqlConnection con = new SqlConnection(connectionString); SqlCommand cmd = new SqlCommand(sql, con); cmd.CommandType = commandType; if (parameters != null) { foreach(SqlParameter parameter in parameters) { cmd.Parameters.Add(parameter); } } con.Open(); count = cmd.ExecuteNonQuery(); con.Close(); return count; } /// <summary> /// 返回当前连接的数据库中所有用户创建的数据库 /// </summary> /// <returns></returns> public DataTable GetTables() { DataTable table = null; using (SqlConnection con = new SqlConnection(connectionString)) { con.Open(); table = con.GetSchema("Tables"); } return table; } }