C# 连接SQL数据库

测试代码：控制台应用

using Newtonsoft.Json;using Newtonsoft.Json.Converters;using System;using System.Collections.Generic;using System.Data;using System.Data.SqlClient;using System.Reflection;namespace XF.ADO.DB{    public class T2    {        public int? fId { get; set; }        public string fname { get; set; }        public string fpass { get; set; }        public DateTime? faddtime { get; set; }        public string ftimespan { get; set; }    }    public class XFDB    {        static void Main()        {                       //查询            string connstr = "Data Source = 127.0.0.1; Initial Catalog = Test; Persist Security Info = True; User ID = sa; Password = xinfu978";            XFDB db = new XFDB(connstr,false);            Console.WriteLine(DateTime.Now.ToString());            try            {                T2 d = new T2();                //d.fId = 1058585;                d.fname = "kkkkkkkkkk";                d.faddtime = DateTime.Now;                for (int i = 0; i < 1000000; i++)                {                    db.FnAdd(d);                }                //int i = db.FnUpdate(d, "fId", "T2");                //d.fname = "qqqqqqqqq";                //i = db.FnUpdate(d, "fId", "T2");                //db.Commit();            }            catch (Exception e)            {                db.Rollback();            }            Console.WriteLine(DateTime.Now.ToString());            db.FnDispost();            Console.ReadKey();        }        string connectString = "";        public XFDB(string connectString,bool isRran = false)        {            this.connectString = connectString;            conn = new SqlConnection(connectString);            conn.Open();            if (isRran)            {                tran = conn.BeginTransaction();            }        }        public void Commit()        {            if (tran != null)            {                tran.Commit();            }        }        public void Rollback()        {            if (tran != null)            {                tran.Rollback();            }        }        public void FnDispost()        {            try            {                conn.Dispose();                tran.Dispose();            }            catch (Exception)            {            }        }        SqlConnection conn = null;        SqlTransaction tran = null;                public DataTable FnSelect(string sqlStr)        {                SqlDataAdapter myDataAdapter = new SqlDataAdapter(sqlStr, conn);                DataSet myDataSet = new DataSet();      // 创建DataSet                myDataAdapter.Fill(myDataSet);                return myDataSet.Tables[0];        }        public T FnSelect<T>(string sqlStr)        {            SqlDataAdapter myDataAdapter = new SqlDataAdapter(sqlStr, conn);            DataSet myDataSet = new DataSet();      // 创建DataSet            myDataAdapter.Fill(myDataSet);            return FnDataTableToList<T>(myDataSet.Tables[0]);        }        public int FnExecute(string sqlStr)        {            SqlCommand cmd = conn.CreateCommand();            if (tran != null)            {                cmd.Transaction = tran;            }            cmd.CommandType = CommandType.Text;            cmd.CommandText = sqlStr;   //sql语句            return cmd.ExecuteNonQuery();        }        public int FnAdd<T>(T obj)        {            string classname = typeof(T).ToString();            classname = classname.Substring(classname.LastIndexOf(".") + 1);            return FnAdd<T>(obj, classname);        }        public int FnAdd<T>(T obj, string mTableName)        {            string key = "";            string val = "";            Type type = obj.GetType();            PropertyInfo[] ps = type.GetProperties();            bool addDo = true;            foreach (PropertyInfo i in ps)            {                Object objq = i.GetValue(obj, null);                if (objq != null)                {                    if (addDo)                    {                        key += $"[{i.Name}]";                        val += $"'{objq}'";                        addDo = false;                    }                    else                    {                        key += $",[{i.Name}]";                        val += $",'{objq}'";                    }                }            }            return FnExecute($"INSERT INTO [dbo].[{mTableName}] ({key}) VALUES ({val})");        }        public int FnUpdate<T>(T obj, string PId, string mTableName)        {            string changes = "";            string where = "";            Type type = obj.GetType();            PropertyInfo[] ps = type.GetProperties();            bool addDo = true;            foreach (PropertyInfo i in ps)            {                Object objq = i.GetValue(obj, null);                if (i.Name == PId.ToString())                {                    if (objq.GetType().ToString().IndexOf("Int") >= 0)                    {                        where = $" WHERE [{PId}] = {objq}";                    }                    else                    {                        where = $" WHERE [{PId}] = '{objq}'";                    }                }                else                {                    if (objq != null)                    {                        if (addDo)                        {                            changes += $"[{i.Name}] = '{objq}'";                            addDo = false;                        }                        else                        {                            changes += $",[{i.Name}] = '{objq}'";                        }                    }                }            }            return FnExecute($"UPDATE [dbo].[{mTableName}] set {changes} {where}");        }        public int FnUpdate<T>(T obj, int PId, string mTableName)        {            string changes = "";            string where = "";            Type type = obj.GetType();            PropertyInfo[] ps = type.GetProperties();            bool addDo = true;            foreach (PropertyInfo i in ps)            {                Object objq = i.GetValue(obj, null);                if (i.Name == PId + "")                {                    where = $" WHERE [{PId}] = {objq}";                    continue;                }                if (objq != null)                {                    if (addDo)                    {                        changes += $"[{i.Name}] = '{objq}'";                        addDo = false;                    }                    else                    {                        changes += $",[{i.Name}] = '{objq}'";                    }                }            }            return FnExecute($"UPDATE [dbo].[{mTableName}] set {changes} {where}");        }        public string FnAdd2<T>(T obj, string mTableName)        {            string key = "";            string val = "";            Type type = obj.GetType();            PropertyInfo[] ps = type.GetProperties();            bool addDo = true;            foreach (PropertyInfo i in ps)            {                Object objq = i.GetValue(obj, null);                if (objq != null)                {                    if (addDo)                    {                        key += $"[{i.Name}]";                        val += $"'{objq}'";                        addDo = false;                    }                    else                    {                        key += $",[{i.Name}]";                        val += $",'{objq}'";                    }                }            }            return $"INSERT INTO [dbo].[{mTableName}] ({key}) VALUES ({val})";        }        public T FnDataTableToList<T>(DataTable dt)        {            return JsonConvert.DeserializeObject<T>(JsonConvert.SerializeObject(dt, new DataTableConverter()));        }        public static object FnOutObjExitPar(object obj, string mOutPar)        {            Type type = obj.GetType();            PropertyInfo[] ps = type.GetProperties();            foreach (PropertyInfo i in ps)            {                if (mOutPar.IndexOf(i.Name) < 0)                {                    i.SetValue(obj, null);                }            }            return obj;        }        static JsonSerializerSettings mJsonSettings = new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore };        public static string ObjectToJson(object obj)        {            return JsonConvert.SerializeObject(obj, Formatting.None, mJsonSettings);        }        public static T JsonToObject<T>(string json)        {            return JsonConvert.DeserializeObject<T>(json);        }    }}

数据库ssms 截图：