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。。。。。
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