C#编程入门--MYSQLHELPER

it2022-05-05  135

using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data; using MySql.Data.MySqlClient; namespace drWm.mdal { public class MySqlHelper { //private static string connstr = @"server=localhost;uid=root;pwd=121535;database=tem;charset=utf8"; private static string connstr = @"Host=127.0.0.1;UserName=root;Password=drpassword;Database=watermonitor;Port=3406;CharSet=utf8;Allow Zero Datetime=true"; #region 执行查询语句,返回MySqlDataReader /// <summary> /// 执行查询语句,返回MySqlDataReader /// </summary> /// <param name="sqlString"></param> /// <returns></returns> public static MySqlDataReader ExecuteReader(string sqlString) { MySqlConnection connection = new MySqlConnection(connstr); MySqlCommand cmd = new MySqlCommand(sqlString, connection); MySqlDataReader myReader = null; try { connection.Open(); myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection); return myReader; } catch (System.Data.SqlClient.SqlException e) { connection.Close(); throw new Exception(e.Message); } finally { if (myReader == null) { cmd.Dispose(); connection.Close(); } } } #endregion #region 执行带参数的查询语句,返回MySqlDataReader /// <summary> /// 执行带参数的查询语句,返回MySqlDataReader /// </summary> /// <param name="sqlString"></param> /// <param name="cmdParms"></param> /// <returns></returns> public static MySqlDataReader ExecuteReader(string sqlString, params MySqlParameter[] cmdParms) { MySqlConnection connection = new MySqlConnection(connstr); MySqlCommand cmd = new MySqlCommand(); MySqlDataReader myReader = null; try { PrepareCommand(cmd, connection, null, sqlString, cmdParms); myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection); cmd.Parameters.Clear(); return myReader; } catch (System.Data.SqlClient.SqlException e) { connection.Close(); throw new Exception(e.Message); } finally { if (myReader == null) { cmd.Dispose(); connection.Close(); } } } #endregion #region 执行sql语句,返回执行行数 /// <summary> /// 执行sql语句,返回执行行数 /// </summary> /// <param name="sql"></param> /// <returns></returns> public static int ExecuteSql(string sql) { using (MySqlConnection conn = new MySqlConnection(connstr)) { using (MySqlCommand cmd = new MySqlCommand(sql, conn)) { try { conn.Open(); int rows = cmd.ExecuteNonQuery(); return rows; } catch (MySql.Data.MySqlClient.MySqlException e) { conn.Close(); throw e; } finally { cmd.Dispose(); conn.Close(); } } } } #endregion #region 执行带参数的sql语句,并返回执行行数 /// <summary> /// 执行带参数的sql语句,并返回执行行数 /// </summary> /// <param name="sqlString"></param> /// <param name="cmdParms"></param> /// <returns></returns> public static int ExecuteSql(string sqlString, params MySqlParameter[] cmdParms) { using (MySqlConnection connection = new MySqlConnection(connstr)) { using (MySqlCommand cmd = new MySqlCommand()) { try { PrepareCommand(cmd, connection, null, sqlString, cmdParms); int rows = cmd.ExecuteNonQuery(); cmd.Parameters.Clear(); return rows; } catch (System.Data.SqlClient.SqlException E) { throw new Exception(E.Message); } finally { cmd.Dispose(); connection.Close(); } } } } #endregion #region 执行查询语句,返回DataSet /// <summary> /// 执行查询语句,返回DataSet /// </summary> /// <param name="sql"></param> /// <returns></returns> public static DataSet GetDataSet(string sql) { using (MySqlConnection conn = new MySqlConnection(connstr)) { DataSet ds = new DataSet(); try { conn.Open(); MySqlDataAdapter DataAdapter = new MySqlDataAdapter(sql, conn); DataAdapter.Fill(ds); } catch (Exception ex) { throw ex; } finally { conn.Close(); } return ds; } } #endregion #region 执行带参数的查询语句,返回DataSet /// <summary> /// 执行带参数的查询语句,返回DataSet /// </summary> /// <param name="sqlString"></param> /// <param name="cmdParms"></param> /// <returns></returns> public static DataSet GetDataSet(string sqlString, params MySqlParameter[] cmdParms) { using (MySqlConnection connection = new MySqlConnection(connstr)) { MySqlCommand cmd = new MySqlCommand(); PrepareCommand(cmd, connection, null, sqlString, cmdParms); using (MySqlDataAdapter da = new MySqlDataAdapter(cmd)) { DataSet ds = new DataSet(); try { da.Fill(ds, "ds"); cmd.Parameters.Clear(); } catch (System.Data.SqlClient.SqlException ex) { throw new Exception(ex.Message); } finally { cmd.Dispose(); connection.Close(); } return ds; } } } #endregion #region 执行带参数的sql语句,并返回object /// <summary> /// 执行带参数的sql语句,并返回object /// </summary> /// <param name="sqlString"></param> /// <param name="cmdParms"></param> /// <returns></returns> public static object GetSingle(string sqlString, params MySqlParameter[] cmdParms) { using (MySqlConnection connection = new MySqlConnection(connstr)) { using (MySqlCommand cmd = new MySqlCommand()) { 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.SqlClient.SqlException e) { throw new Exception(e.Message); } finally { cmd.Dispose(); connection.Close(); } } } } #endregion /// <summary> /// 执行存储过程,返回数据集 /// </summary> /// <param name="storedProcName">存储过程名</param> /// <param name="parameters">存储过程参数</param> /// <returns>DataSet</returns> public static DataSet RunProcedureForDataSet(string storedProcName, IDataParameter[] parameters) { using (MySqlConnection connection = new MySqlConnection(connstr)) { DataSet dataSet = new DataSet(); connection.Open(); MySqlDataAdapter sqlDA = new MySqlDataAdapter(); sqlDA.SelectCommand = BuildQueryCommand(connection, storedProcName, parameters); sqlDA.Fill(dataSet); connection.Close(); return dataSet; } } /// <summary> /// 构建 SqlCommand 对象(用来返回一个结果集,而不是一个整数值) /// </summary> /// <param name="connection">数据库连接</param> /// <param name="storedProcName">存储过程名</param> /// <param name="parameters">存储过程参数</param> /// <returns>SqlCommand</returns> private static MySqlCommand BuildQueryCommand(MySqlConnection connection, string storedProcName, IDataParameter[] parameters) { MySqlCommand command = new MySqlCommand(storedProcName, connection); command.CommandType = CommandType.StoredProcedure; foreach (MySqlParameter parameter in parameters) { command.Parameters.Add(parameter); } return command; } #region 装载MySqlCommand对象 /// <summary> /// 装载MySqlCommand对象 /// </summary> private static void PrepareCommand(MySqlCommand cmd, MySqlConnection conn, MySqlTransaction trans, string cmdText, MySqlParameter[] 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 (MySqlParameter parm in cmdParms) { cmd.Parameters.Add(parm); } } } #endregion } }

 

转载于:https://www.cnblogs.com/tyqing/p/8649403.html


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