SQLHelper--四种方法完整版
主要分为三部分：
（1） 配置文件
（2）Program.cs
（3）SQLHelper.cs
//--------------------------------------1 配置文件-----------------------------------------------------------------------------------
//--------------------------------------2 Program.cs---------------------------------------------------------------------------------
using System;
using System.Collections.Generic;
using System.Data.SqlClient;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace _11SQLHelper
{
class Program
{
static void Main(string[] args)
{
// 对数据库的增删改查
// 创建数据库
//string createtable = "create table Test0806(id int not null, name nvarchar(10), pwd varchar(10))";
//int res = JKLibrary.SQLHelper.ExecuteNonQuery(createtable);
//Console.WriteLine(res);
// 插入数据
#region 无参数，增加数据
//string sql = "insert into Test0806(id, name, pwd) values (1, N'赵晓虎','TigerZhao');";
//int res = JKLibrary.SQLHelper.ExecuteNonQuery(sql);
//Console.WriteLine(res);
#endregion
#region 参数化增加
//string sql = "insert into Test0806(id, name, pwd) values (@id, @name, @pwd);";
//SqlParameter[] ps = {
// new SqlParameter("@id", (object)2),
// new SqlParameter("@name", "赵剑宇"),
// new SqlParameter("@pwd", "happyZhao")
// };
//int res = JKLibrary.SQLHelper.ExecuteNonQuery(sql, ps);
//Console.WriteLine(res);
#endregion
// 修改
#region 参数化修改
//string sql = "update Test0806 set name=@name where id=@id;";
//SqlParameter[] ps = {
// new SqlParameter("@name", "赵晓"),
// new SqlParameter("@id", (object)2)
// };
//int res = JKLibrary.SQLHelper.ExecuteNonQuery(sql, ps);
#endregion
// 删除
//string sql = "delete from Test0806 where name=@name;";
//SqlParameter pName = new SqlParameter("@name", "赵晓");
//int count = JKLibrary.SQLHelper.ExecuteNonQuery(sql, pName);
//Console.WriteLine(count);
// 查询姓赵的有多少人？
#region Scalar
//string sql = "select count(*) from Test0806 where name like @name;";
//SqlParameter pName = new SqlParameter("@name", "赵%");
//int count = (int)JKLibrary.SQLHelper.ExecuteScalar(sql, pName);
//Console.WriteLine(count);
#endregion
// 读取数据
#region 读取数据
//using (SqlDataReader reader = JKLibrary.SQLHelper.ExecuteReader("select * from Test0806;"))
//{
// while (reader.Read())
// {
// List
// for(int i=0;i
// list.Add(reader[i].ToString());
// }
// Console.WriteLine(string.Join(",", list));
// }
//}
//Console.WriteLine("OK");
#endregion
string sql = "select * from TestDataBase..Student;";
using (StreamWriter writer = new StreamWriter("s.txt", true, Encoding.Default))
{
using (SqlDataReader reader = JKLibrary.SQLHelper.ExecuteReader(sql))
{
List
while (reader.Read())
{
list.Clear();
for (int i = 0; i < reader.FieldCount; i++)
{
list.Add(reader[i].ToString());
}
writer.WriteLine(string.Join(",", list));
}
}
}
Console.WriteLine("OK");
Console.ReadKey();
}
}
}
//--------------------------------------3 SQLHelper.cs---------------------------------------------------------------------------------
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace JKLibrary
{
// 提供执行方法
public class SQLHelper
{
// 连接字符串
static string connStr = ConfigurationManager.ConnectionStrings["sql"].ConnectionString;
public static int ExecuteNonQuery(string sql, params SqlParameter[] ps)
{
using (SqlConnection conn = new SqlConnection(connStr))
{
using (SqlCommand cmd = new SqlCommand(sql, conn))
{
cmd.Parameters.AddRange(ps);
conn.Open();
return cmd.ExecuteNonQuery();
}
}
}// ExecuteNonQuery End
// ExecuteScalar 方法
public static object ExecuteScalar(string sql, params SqlParameter[] ps)
{
using (SqlConnection conn = new SqlConnection(connStr))
{
using (SqlCommand cmd = new SqlCommand(sql, conn))
{
cmd.Parameters.AddRange(ps);
conn.Open();
return cmd.ExecuteScalar();
}
}
}
public static SqlDataReader ExecuteReader(string sql, params SqlParameter[] ps)
{
SqlConnection conn = new SqlConnection(connStr);
try
{
using (SqlCommand cmd = new SqlCommand(sql, conn))
{
cmd.Parameters.AddRange(ps);
conn.Open();
return cmd.ExecuteReader(System.Data.CommandBehavior.CloseConnection);
}
}
catch(Exception ex)
{
// 如果cmd执行错误，从这里将异常抛出
conn.Dispose();
throw ex;
}
}
public static DataSet GetDataSet(string sql, params SqlParameter[] ps)
{
DataSet ds = new DataSet();
using (SqlDataAdapter sda = new SqlDataAdapter(sql, connStr))
{
sda.SelectCommand.Parameters.AddRange(ps);
sda.Fill(ds);
}
return ds;
}
}
}