泛型连接数据库

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2024-07-02 03:54:27 231人阅读

这些天用泛型做了一个数据库的底层，自我感觉很方便，但是功能不是很完善，会继续考虑下去下面给大家分享一下代码

1数据库连接的帮助类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.SqlClient;

namespace DAL
{

    public class DBHelper
    {
        /// <summary>
        /// 从web.config中获得数据库连接字符串
        /// </summary>
        public static string Connstr = "Data Source=.;Initial Catalog=Pet;Integrated Security=True";

        #region sql语句部分


        /// <summary>
        /// 执行sql语句返回DataTable
        /// </summary>
        /// <param name="sql">sql</param>
        /// <returns>根据sql语句得到所有记录</returns>
        public static DataTable GetDataTable(string sql)
        {

            using (SqlConnection conn = new SqlConnection(Connstr))
            {

                SqlDataAdapter sda = new SqlDataAdapter(sql, conn);
                DataTable dt = new DataTable();
                sda.Fill(dt);
                return dt;


            }


        }

        /// <summary>
        /// 执行带参数的sql语句返回DataTable
        /// </summary>
        /// <param name="sql">带参数的sql语句</param>
        /// <param name="values">参数</param>
        /// <returns>根据sql语句得到所有记录</returns>
        public static DataTable GetDataTable(string sql, params SqlParameter[] values)
        {
            using (SqlConnection conn = new SqlConnection(Connstr))
            {
                SqlCommand cmd = new SqlCommand(sql, conn);
                conn.Open();
                cmd.Parameters.AddRange(values);
                SqlDataAdapter sda = new SqlDataAdapter(cmd);
                DataTable dt = new DataTable();
                sda.Fill(dt);
                conn.Close();
                return dt;
            }


        }


        /// <summary>
        /// 执行无参数的sql语句
        /// </summary>
        /// <param name="sql">sql语句</param>
        /// <returns>影响的行数</returns>
        public static int ExecuteCommand(string sql)
        {
            using (SqlConnection conn = new SqlConnection(Connstr))
            {
                SqlCommand cmd = new SqlCommand(sql, conn);
                conn.Open();
                int num = cmd.ExecuteNonQuery();
                conn.Close();
                return num;
            }
        }


        /// <summary>
        /// 执行有参数的sql语句
        /// </summary>
        /// <param name="sql">sql语句</param>
        /// <param name="values">参数</param>
        /// <returns>影响的行数</returns>
        public static int ExecuteCommand(string sql, params SqlParameter[] values)
        {
            using (SqlConnection conn = new SqlConnection(Connstr))
            {
                SqlCommand cmd = new SqlCommand(sql, conn);
                cmd.Parameters.AddRange(values);
                conn.Open();
                int num = Convert.ToInt32(cmd.ExecuteNonQuery());
                conn.Close();
                return num;
            }
        }
        /// <summary>
        /// 执行无参数的sql语句，返回首行首列
        /// </summary>
        /// <param name="sql">sql语句</param>
        /// <returns>返回首行首列</returns>
        public static object GetScalar(string sql)
        {
            using (SqlConnection conn = new SqlConnection(Connstr))
            {
                SqlCommand cmd = new SqlCommand(sql, conn);
                conn.Open();
                object obj = cmd.ExecuteScalar();
                conn.Close();
                return obj;
            }
        }
        /// <summary>
        /// 执行有参数的sql语句,返回首行首列
        /// </summary>
        /// <param name="sql">sql语句</param>
        /// <param name="values">参数,是否返回首行首列</param>
        /// <returns>返回首行首列</returns>
        public static object ExecuteScalar(string sql, params SqlParameter[] values)
        {
            using (SqlConnection conn = new SqlConnection(Connstr))
            {
                SqlCommand cmd = new SqlCommand(sql, conn);
                cmd.Parameters.AddRange(values);
                conn.Open();
                object obj = cmd.ExecuteScalar();
                conn.Close();
                return obj;
            }
        }

        /// <summary>
        /// 带事务的执行多条sql语句
        /// </summary>
        /// <param name="sqls"></param>    
        /// <returns></returns>
        //public static bool ExecuteCommandByTran(params ExecuteSql[] sqls)
        //{

        //    using (SqlConnection conn = new SqlConnection(Connstr))
        //    {
        //        conn.Open();
        //        //为数据库连接打开事务
        //        SqlTransaction tran = conn.BeginTransaction();
        //        SqlCommand cmd = new SqlCommand();
        //        cmd.Connection = conn;
        //        //为命令对象指定要应用事务
        //        cmd.Transaction = tran;
        //        try
        //        {

        //            for (int i = 0; i < sqls.Length; i++)
        //            {
        //                cmd.CommandText = sqls[i].SqlString;
        //                cmd.Parameters.AddRange(sqls[i].Pars);
        //                cmd.ExecuteNonQuery();
        //            }

        //            //没有异常的情况下，提交事务
        //            tran.Commit();

        //            return true;
        //        }
        //        catch (Exception ex)
        //        {
        //            //事务滚回去
        //            tran.Rollback();

        //            return false;

        //        }
        //        finally
        //        {

        //            conn.Close();
        //        }

        //    }
        //}

        #endregion

        #region 存储过程部分
        /// <summary>
        /// 执行sql语句返回DataTable
        /// </summary>
        /// <param name="sql">安全的sql语句</param>
        /// <returns>根据sql语句得到所有记录</returns>
        public static DataTable GetDataTableByProcedure(string sql)
        {

            using (SqlConnection conn = new SqlConnection(Connstr))
            {

                SqlCommand cmd = new SqlCommand(sql, conn);
                cmd.CommandType = CommandType.StoredProcedure;
                conn.Open();
                SqlDataAdapter sda = new SqlDataAdapter(cmd);
                DataTable dt = new DataTable();
                sda.Fill(dt);
                conn.Close();
                return dt;


            }


        }
        /// <summary>
        /// 执行带参数的sql语句返回DataTable
        /// </summary>
        /// <param name="sql">带参数的sql语句</param>
        /// <param name="values">参数</param>
        /// <returns>根据sql语句得到所有记录</returns>
        public static DataTable GetDataTableByProcedure(string sql, params SqlParameter[] values)
        {
            using (SqlConnection conn = new SqlConnection(Connstr))
            {
                SqlCommand cmd = new SqlCommand(sql, conn);
                //指定查询的方式使用存储过程
                cmd.CommandType = CommandType.StoredProcedure;
                conn.Open();
                cmd.Parameters.AddRange(values);
                SqlDataAdapter sda = new SqlDataAdapter(cmd);
                DataTable dt = new DataTable();
                sda.Fill(dt);
                conn.Close();
                return dt;
            }


        }


        /// <summary>
        /// 执行无参数的sql语句
        /// </summary>
        /// <param name="sql">sql语句</param>
        /// <returns>影响的行数</returns>
        public static int ExecuteCommandByProcedure(string sql)
        {
            using (SqlConnection conn = new SqlConnection(Connstr))
            {
                SqlCommand cmd = new SqlCommand(sql, conn);
                cmd.CommandType = CommandType.StoredProcedure;
                conn.Open();
                int num = cmd.ExecuteNonQuery();
                conn.Close();
                return num;
            }
        }


        /// <summary>
        /// 执行有参数的sql语句
        /// </summary>
        /// <param name="sql">sql语句</param>
        /// <param name="values">参数</param>
        /// <returns>影响的行数</returns>
        public static int ExecuteCommandByProcedure(string sql, params SqlParameter[] values)
        {
            using (SqlConnection conn = new SqlConnection(Connstr))
            {
                SqlCommand cmd = new SqlCommand(sql, conn);
                cmd.CommandType = CommandType.StoredProcedure;
                cmd.Parameters.AddRange(values);
                conn.Open();
                int num = cmd.ExecuteNonQuery();
                conn.Close();
                return num;
            }
        }
        /// <summary>
        /// 执行无参数的sql语句，返回首行首列
        /// </summary>
        /// <param name="sql">sql语句</param>
        /// <returns>返回首行首列</returns>
        public static object GetScalarByProcedure(string sql)
        {
            using (SqlConnection conn = new SqlConnection(Connstr))
            {
                SqlCommand cmd = new SqlCommand(sql, conn);
                cmd.CommandType = CommandType.StoredProcedure;
                conn.Open();
                object obj = cmd.ExecuteScalar();
                conn.Close();
                return obj;
            }
        }
        /// <summary>
        /// 执行有参数的sql语句,返回首行首列
        /// </summary>
        /// <param name="sql">sql语句</param>
        /// <param name="values">参数,是否返回首行首列</param>
        /// <returns>返回首行首列</returns>
        public static object ExecuteScalarByProcedure(string sql, params SqlParameter[] values)
        {
            using (SqlConnection conn = new SqlConnection(Connstr))
            {
                SqlCommand cmd = new SqlCommand(sql, conn);
                cmd.CommandType = CommandType.StoredProcedure;
                cmd.Parameters.AddRange(values);
                conn.Open();
                object obj = cmd.ExecuteScalar();
                conn.Close();
                return obj;
            }
        }
        #endregion
        
        #region 帮助方法

        //判断是否为主键
        public static bool IsPrimaryKey(String columnName, String tableName)
        {
            using (SqlConnection conn = new SqlConnection(Connstr))
            {
                conn.Open();
                SqlParameter[] parameters = new SqlParameter[3];
                parameters[0] = new SqlParameter("@table_name", tableName);
                parameters[1] = new SqlParameter("@table_owner", null);
                parameters[2] = new SqlParameter("@table_qualifier", null);
                SqlCommand comm = new SqlCommand();
                //指定存储过程名称
                comm.CommandText = "sp_pkeys";
                comm.Connection = conn;
                //声明执行命令的类型
                comm.CommandType = CommandType.StoredProcedure;
                comm.Parameters.AddRange(parameters);
                SqlDataAdapter ad = new SqlDataAdapter(comm);
                DataTable dt = new DataTable();
                ad.Fill(dt);
                DataRowCollection drc = dt.Rows;
                if (drc.Count == 0 || (drc[0]["COLUMN_NAME"].ToString().ToLower() != columnName.ToLower()))
                    return false;
                else
                    return true;
            }

        }
        //判断是否为外键
        public static bool IsForeignKey(String columnName, String tableName)
        {
            using (SqlConnection conn = new SqlConnection(Connstr))
            {
                conn.Open();
                SqlParameter[] parameters = new SqlParameter[3];
                parameters[0] = new SqlParameter("@pktable_name", tableName);
                parameters[1] = new SqlParameter("@pktable_owner", null);
                parameters[2] = new SqlParameter("@pktable_qualifier", null);
                SqlCommand comm = new SqlCommand();
                //指定存储过程名称
                comm.CommandText = "sp_fkeys";
                comm.Connection = conn;
                //声明执行命令的类型
                comm.CommandType = CommandType.StoredProcedure;
                comm.Parameters.AddRange(parameters);
                SqlDataAdapter ad = new SqlDataAdapter(comm);
                DataTable dt = new DataTable();
                ad.Fill(dt);
                DataRowCollection drc = dt.Rows;
                if (drc.Count == 0 || (drc[0]["COLUMN_NAME"].ToString().ToLower() != columnName.ToLower()))
                    return false;
                else
                    return true;
            }

        }
        #endregion
    }
}

2BaseDAL定义了一些主要的增删改查的方法因为只是开始做所以只能是对单张表的操作

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Reflection;
using Model;

namespace DAL
{
    public abstract class BassDAL<T> where T : new()
    {
        //单表查询
        public virtual List<T> GetAllModels()
        {
            List<T> tList = new List<T>();
            string name = new T().GetType().Name;
            string sqlStr = "select * from " + name;
            DataTable dt = DBHelper.GetDataTable(sqlStr);

            foreach (DataRow dr in dt.Rows)
            {
                T t = new T();
                PropertyInfo[] proList = t.GetType().GetProperties();
                foreach (PropertyInfo pi in proList)
                {
                    string piName = pi.Name;
                    if (dt.Columns.Contains(piName))
                    {
                        if (!pi.CanWrite) continue;
                        object value =http://www.mamicode.com/ dr[piName];
                        if (value != DBNull.Value)
                            pi.SetValue(t, value, null);
                    }
                }
                tList.Add(t);
            }
            return tList;
        }
        //添加
        public virtual bool AddModel(T model)
        {
            PropertyInfo[] proList = model.GetType().GetProperties();
            string name = model.GetType().Name;
            string sqlStr = "insert into " + name;
            string filed = "(";
            string values = " values (";

            foreach (PropertyInfo pi in proList)
            {
                filed += pi.Name + ",";
                values += "‘" + pi.GetValue(model, null).ToString() + "‘,";
            }
            filed = filed.Substring(0, filed.Length - 1) + ")";
            values = values.Substring(0, values.Length - 1) + ")";
            sqlStr = sqlStr + filed + values;
            return DBHelper.ExecuteCommand(sqlStr) != 0 ? true : false;
        }
        //修改
        public virtual bool UpdateModel(T model)
        {
            PropertyInfo[] proList = model.GetType().GetProperties();
            string name = model.GetType().Name;
            string sqlStr = "update " + name + " set ";
            foreach (PropertyInfo pi in proList)
            {
                if (pi.GetValue(model, null) != null && DBHelper.IsPrimaryKey(pi.Name, name) == false)
                {
                    sqlStr += pi.Name + "=‘" + pi.GetValue(model, null).ToString() + "‘,";
                }
            }
            sqlStr = sqlStr.Substring(0, sqlStr.Length - 1);
            foreach (PropertyInfo pi in proList)
            {
                if (pi.GetValue(model, null) != null && DBHelper.IsPrimaryKey(pi.Name, name) != false)
                {
                    sqlStr += " where " + pi.Name + "=‘" + pi.GetValue(model, null).ToString() + "‘";
                }
            }
            return DBHelper.ExecuteCommand(sqlStr) != 0 ? true : false;
        }
        //删除
        public virtual bool DeleteModel(T model)
        {
            PropertyInfo[] proList = model.GetType().GetProperties();
            string name = model.GetType().Name;
            string sqlStr = "delete " + name + " where ";
            foreach (PropertyInfo pi in proList)
            {
                if (pi.GetValue(model, null) != null)
                {
                    if (DBHelper.IsPrimaryKey(pi.Name, name) != false)
                    {
                        sqlStr += pi.Name + "=‘" + pi.GetValue(model, null).ToString()+"‘";
                    }
                }
            }
            return DBHelper.ExecuteCommand(sqlStr) != 0 ? true : false;
        }
    }
}

3使用BaseDAL

用实体类的DAL继承BaseDAL由于BaseDAL是一个泛型类所以要在继承的时候传入实体类即BassDAL<PetInfo>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Model;

namespace DAL
{
    public class Pet:BassDAL<PetInfo>
    {
    }
}

4这样就可以使用了

using System;
using System.Collections;
using System.Configuration;
using System.Data;

using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;

using DAL;
using Model;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        PetInfo petinfo = new PetInfo
        {
             Id = 1,
        };
        new Pet().DeleteModel(petinfo);
        this.GridView1.DataSource = new Pet().GetAllModels();
        this.GridView1.DataBind();
        
    }
}

有什么不足希望大家指出来，一起完善哈

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泛型连接数据库

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