C# SQL封装（三）

本篇接C# SQL（二）

在其代码上继续扩展 删操作 ， 让我们开始吧。。。。

一 ： 构建T-SQL语句（在SQL_Structure.cs中添加一个方法 DELETE_T_SQL ， 用于构建delete的T-SQL）

using DBDome.model;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
namespace DBDome.com
{
    /// <summary>
    /// SQL构建器(还没与赋值)
    /// </summary>
    public sealed class SQL_Structure
    {
        private SQL_Structure() { }
        /// <summary>
        /// 添加一个数据的T-SQL的构成
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="model"></param>
        /// <returns></returns>
        public static string ADD_T_SQL<T>( T model ) where T : BaseModel
        {
            string base_add = @"insert into [{0}] ({1}) values ({2})";//表名 ， 列明 ， 对应的值
            Type model_type = model.GetType();
            string[] arr = model_type.Name.Split(new char[] { '.' });
            string table_name = arr[arr.Length - 1];//获得表的名称
            PropertyInfo[] p_intos = model_type.GetProperties();
            StringBuilder table_field_name = new StringBuilder();
            StringBuilder table_field_value = new StringBuilder();
            PropertyInfo item = null;
            for (int i = 0; i < p_intos.Length; i++)
            {
                item = p_intos[i];
                if (item.Name != "id")//不应添加主键
                {
                    table_field_name.Append(item.Name + ",");
                    table_field_value.Append("@" + item.Name + ",");
                }
            }
            return String.Format(base_add, table_name, table_field_name.ToString().Substring(0, table_field_name.ToString().Length-1), table_field_value.ToString().Substring(0,table_field_value.ToString().Length-1));
        }
        /// <summary>
        /// 删除一条数据的T-SQL构成(以ID号来删除)
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="model"></param>
        /// <returns></returns>
        public static string DELETE_T_SQL<T>(T model) where T : BaseModel
        {
            string base_delete = @"delete from [{0}] where {1} = {2}";
            Type model_type = model.GetType();
            string[] arr = model_type.Name.Split(new char[] { '.' });
            string table_name = arr[arr.Length - 1];//获得表的名称
            PropertyInfo[] p_intos = model_type.GetProperties();
            PropertyInfo item = null;
            for (int i = 0; i < p_intos.Length; i++)
            {
                item = p_intos[i];
                if (item.Name == "id")
                {
                    //返回T-SQL构建
                    return string.Format( base_delete ,
                        table_name,
                        item.Name,
                        "@" + item.Name
                        );
                }
            }
            return string.Empty;
        }
    }
}

二 ： 构建SqlParameter参数 （在SqlParameter_Structure.as中添加方法DELETE_T_SQL）

using DBDome.model;
using System;
using System.Collections.Generic;
using System.Data.SqlClient;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Data;
namespace DBDome.com
{
    /// <summary>
    /// SqlParameter 
    /// </summary>
    public sealed class SqlParameter_Structure
    {
        private SqlParameter_Structure() { }
        /// <summary>
        /// 构建T-SQL参数 ADD
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="model"></param>
        /// <returns></returns>
        public static SqlParameter[] ADD_T_SQL<T>(T model) where T : BaseModel
        {
            Type model_type = model.GetType();
            PropertyInfo[] p_intos = model_type.GetProperties();
            SqlParameter[] sql_param = new SqlParameter[p_intos.Length - 1];//不需要主键
            PropertyInfo item = null;
            string p_name = "";
            SqlParameter cell = null;
            int j = 0;
            for (int i = 0; i < p_intos.Length; i++)
            {
                item = p_intos[i];
                p_name = item.Name;
                if (p_name == "id") continue;
               // Console.WriteLine("字段 {0} 的类型为 {1} ", p_name ,item.PropertyType);
                cell = new SqlParameter(p_name, SqlParameter_Structure.Get_SqlDbType_SqlType(item.PropertyType));
                cell.Value = item.GetValue(model, null);
                sql_param[j] = cell;
                j++;
            }
            return sql_param;
        }
        /// <summary>
        /// 构建T-SQL参数 DELETE
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="model"></param>
        /// <returns></returns>
        public static SqlParameter[] DELETE_T_SQL<T>(T model) where T : BaseModel
        {
            Type model_type = model.GetType();
            PropertyInfo[] p_intos = model_type.GetProperties();
            SqlParameter[] sql_param = new SqlParameter[1];//只需要主键
            PropertyInfo item = null;
            for (int i = 0; i < p_intos.Length; i++)
            {
                item = p_intos[i];
                if (item.Name != "id") continue;
                SqlParameter cell = new SqlParameter(item.Name, SqlParameter_Structure.Get_SqlDbType_SqlType(item.PropertyType));
                cell.Value = item.GetValue(model, null);
                sql_param[0] = cell;
                break;
            }
            return sql_param;
        }
        private static SqlDbType Get_SqlDbType_SqlType(Type cshaper)
        {
            string[] arr = cshaper.ToString().Split(new char[] { '.' });
            string toLow = arr[arr.Length - 1].ToLower();
            switch (toLow)
            { 
                case "string":
                    return SqlDbType.NVarChar;
                    break;
                case "int16":
                    return SqlDbType.Bit;
                    break;
                case "int32":
                    return SqlDbType.Int;
                    break;
                default:
                    throw new Exception(String.Format("T-SQL参数没有配对的类型 {0}" ,cshaper));
                    break;
            }
        }
    }
}

三 ： 测试

先查下数据库 ， 看看能删除的数据：

编写测试代码 ， 开始测试

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using DBDome.com;
using DBDome.model;
using System.Data.SqlClient;
using System.Data;

namespace DBDome
{
    class Program
    {
        static void Main(string[] args)
        {
            #region 添加一条记录
            /*
            User kayer_new = new User();
            kayer_new.name = "kayer";
            kayer_new.sex = 1;
            kayer_new.lv = 1;
            kayer_new.username = "Kayer";
            kayer_new.userpwd = "123";

            string into_sql = SQL_Structure.ADD_T_SQL<User>(kayer_new);
            Console.WriteLine(into_sql);
           
            SqlParameter[] a = SqlParameter_Structure.ADD_T_SQL<User>(kayer_new);
            string c =  SqlHelper.connectionString;
            Console.WriteLine(c);
           
            int i = SqlHelper.ExecteNonQuery(CommandType.Text, into_sql, a);
            if (i > 0)
            {
                Console.WriteLine("执行操作成功");
            }
            else
            {
                Console.WriteLine("执行操作失败");
            }
             */
            #endregion
            #region 删除一条记录
            User kayer_delete = new User();
            kayer_delete.id = 2;

            string delete_sql = SQL_Structure.DELETE_T_SQL<User>(kayer_delete);
            Console.WriteLine(delete_sql);

            SqlParameter[] dedete_p = SqlParameter_Structure.DELETE_T_SQL<User>(kayer_delete);
            int i = SqlHelper.ExecteNonQuery(CommandType.Text, delete_sql, dedete_p);
            if (i > 0)
            {
                Console.WriteLine("执行操作成功");
            }
            else
            {
                Console.WriteLine("执行操作失败");
            }
            #endregion
            Console.Read();
        }
    }
}

结果如下：

数据库

未完待续。。。。。