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  • MYSQL连接数据库

    web.config
    
      <connectionStrings>
    <add name="MysqlDB" connectionString="Data Source=.;Initial Catalog=dbname;Persist Security Info=True;User ID=username;Password=password;"
    providerName="MySql.Data.MySqlClient" /> </connectionStrings> ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// using MySql.Data.MySqlClient; using System; using System.Collections.Generic; using System.Data; using System.Linq; using System.Reflection; using System.Text; using System.Threading.Tasks; namespace Service.Common { public class DbMyHelp { //连接字符串拼装 //mycon = new MySqlConnection("Host=127.0.0.1;UserName=root;Password=root;Database=score;Port=3306"); //private static string config = System.Configuration.ConfigurationManager.AppSettings["MysqlDB"].ToString(); private string config = string.Empty; /// <summary> /// 数据库连接串 /// </summary> public string ConnectionString { set { config = value; } } /// <summary> /// 构造 /// </summary> public DbMyHelp(string connName) { this.config = System.Configuration.ConfigurationManager.ConnectionStrings[connName].ToString(); } /// <summary> /// 查询返回List<T> /// </summary> /// <typeparam name="T"></typeparam> /// <param name="sql"></param> /// <returns></returns> public List<T> QueryList<T>(string sql) { ///////////////////获取MYSQ看数据返回值//////////////////////////// MySqlConnection mycon = new MySqlConnection(config); //连接 mycon.Open(); //查询命令赋值,可以写多条语句,多条语句之间用;号隔开 MySqlCommand mycom = new MySqlCommand(sql, mycon); MySqlDataReader myrec = mycom.ExecuteReader(); List<T> list = new List<T>(); //一次次读,读不到就结束 while (myrec.Read()) { T obj = ExecDataReader<T>(myrec); list.Add(obj); //string myInfo = myInfo + myrec["Name"] + " " + myrec["ID"]; } //////关闭相关对象 myrec.Close(); mycom.Dispose(); mycon.Close(); return list; } /// <summary> /// 查询返回object /// </summary> /// <param name="sql"></param> /// <returns></returns> public object QueryObject(string sql) { ///////////////////获取MYSQ看数据返回值//////////////////////////// MySqlConnection mycon = new MySqlConnection(config); //连接 mycon.Open(); //查询命令赋值,可以写多条语句,多条语句之间用;号隔开 MySqlCommand mycom = new MySqlCommand(sql, mycon); object obj = mycom.ExecuteScalar(); //////关闭相关对象 mycom.Dispose(); mycon.Close(); return obj; } /// <summary> /// 查询返回datatable /// </summary> /// <param name="sql"></param> /// <returns></returns> public DataTable QueryTable(string sql) { MySqlConnection mycon = new MySqlConnection(config); mycon.Open(); MySqlCommand mycom = new MySqlCommand(sql, mycon); DataSet dataset = new DataSet();//dataset放执行后的数据集合 MySqlDataAdapter adapter = new MySqlDataAdapter(mycom); adapter.Fill(dataset); mycom.Dispose(); mycon.Close(); return dataset.Tables[0]; } /// <summary> /// 操作增删改 /// </summary> /// <param name="sql"></param> /// <returns></returns> public int ExecutSql(string sql) { int result = 0; MySqlConnection mycon = new MySqlConnection(config); mycon.Open(); MySqlCommand mycom = new MySqlCommand(sql, mycon); result = mycom.ExecuteNonQuery(); mycom.Dispose(); mycon.Close(); mycon.Dispose(); return result; } /// <summary> /// 事务操作增删改 /// </summary> /// <param name="sql"></param> /// <returns></returns> public int ExcuteTran(string sql) { MySqlConnection mycon = new MySqlConnection(config); MySqlCommand mycom = null; MySqlTransaction trans = null; int result = 0; try { mycon.Open(); mycom = mycon.CreateCommand(); mycom.CommandText = sql; //创建事务 trans = mycon.BeginTransaction(); result = mycom.ExecuteNonQuery(); //事务提交 trans.Commit(); } catch { //事务回滚 trans.Rollback(); } finally { mycom.Dispose(); mycon.Close(); mycon.Dispose(); } return result; } /// <summary> /// IDataReader、MySqlDataReader 转T实体 /// </summary> /// <typeparam name="T"></typeparam> /// <param name="reader"></param> /// <returns></returns> private T ExecDataReader<T>(IDataReader reader) { T obj = default(T); try { Type type = typeof(T); obj = (T)Activator.CreateInstance(type);//从当前程序集里面通过反射的方式创建指定类型的对象 PropertyInfo[] propertyInfos = type.GetProperties();//获取指定类型里面的所有属性 foreach (PropertyInfo propertyInfo in propertyInfos) { for (int i = 0; i < reader.FieldCount; i++) { string fieldName = reader.GetName(i); if (fieldName.ToLower() == propertyInfo.Name.ToLower()) { //object val = reader[propertyInfo.Name];//读取表中某一条记录里面的某一列 object val = reader[fieldName];//读取表中某一条记录里面的某一列 if (val != null && val != DBNull.Value) { propertyInfo.SetValue(obj, val); } break; } } } } catch (Exception) { throw; } return obj; } } public static class DataHelper { /// <summary> /// DataTable 转List<T>实体 /// </summary> /// <typeparam name="T"></typeparam> /// <param name="dt"></param> /// <returns></returns> public static List<T> ToEntity<T>(this DataTable dt) where T : new() { List<T> list = new List<T>(); Type info = typeof(T); var props = info.GetProperties(); foreach (DataRow dr in dt.Rows) { T entity = new T(); foreach (var pro in props) { var propInfo = info.GetProperty(pro.Name); if (dt.Columns.Contains(pro.Name)) { propInfo.SetValue(entity, Convert.ChangeType(dr[pro.Name], propInfo.PropertyType), null); } } list.Add(entity); } return list; } } }
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  • 原文地址:https://www.cnblogs.com/chxl800/p/5752394.html
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