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  • C#_JDBC连接数据库

      1 using System;
      2 using System.Collections.Generic;
      3 using System.Linq;
      4 using System.Text;
      5 using System.Threading.Tasks;
      6 using System.Data.SqlClient;
      7 using System.Data;
      8 
      9 namespace MySchool.DAL
     10 {
     11     public class DBHelper
     12     {
     13         //private const string conn = "Data Source=.;Initial Catalog=MySchool;User ID=GaoFei;Password=111111";
     14         private const string conn = "Data Source=.;Initial Catalog=MySchool;User ID=sa;Password=sa";
     15         private static SqlConnection connection = new SqlConnection(conn);
     16 
     17 
     18         /// <summary>
     19         /// 读取数据
     20         /// </summary>
     21         /// <returns></returns>
     22         public static SqlDataReader Reader(string sql)
     23         {
     24             try
     25             {
     26                 connection.Open();
     27                 SqlCommand comm = new SqlCommand(sql, connection);
     28                 return comm.ExecuteReader(CommandBehavior.CloseConnection);
     29             }
     30             catch (Exception ex)
     31             {
     32                 throw;
     33             }
     34         }
     35 
     36         /// <summary>
     37         /// 增删改数据
     38         /// </summary>
     39         /// <param name="sql"></param>
     40         /// <returns></returns>
     41         public static int ExecuteNonQuery(string sql)
     42         {
     43             try
     44             {
     45                 connection.Open();   //打开数据库连接
     46                 SqlCommand comm = new SqlCommand(sql, connection);
     47                 return comm.ExecuteNonQuery();
     48             }
     49             catch (Exception ex)
     50             {
     51                 throw;
     52             }
     53             finally
     54             {
     55                 connection.Close();
     56             }
     57         }
     58         /// <summary>
     59         /// 返回单个值
     60         /// </summary>
     61         /// <param name="sql"></param>
     62         /// <returns></returns>
     63         public static object ExecuteScalar(string sql)
     64         {
     65             try
     66             {
     67                 connection.Open();   //打开数据库连接
     68                 SqlCommand comm = new SqlCommand(sql, connection);
     69                 return comm.ExecuteScalar();
     70 
     71             }
     72             catch (Exception)
     73             {
     74                 throw;
     75             }
     76             finally
     77             {
     78                 connection.Close();
     79             }
     80         }
     81         /// <summary>
     82         /// 返回数据集
     83         /// </summary>
     84         /// <param name="sql"></param>
     85         /// <param name="tableName"></param>
     86         /// <returns></returns>
     87         public static DataSet Fill(string sql, string tableName)
     88         {
     89             try
     90             {
     91                 connection.Open();  //打开连接
     92                 //创建数据适配器对象
     93                 SqlDataAdapter sda = new SqlDataAdapter(sql, connection);
     94                 //创建数据集
     95                 DataSet ds = new DataSet();
     96                 sda.Fill(ds, tableName); //填充数据集
     97                 return ds;
     98             }
     99             catch (Exception ex)
    100             {
    101                 throw;
    102                 //将异常引发出现
    103                 //  throw new Exception(e.Message);
    104             }
    105             finally
    106             {
    107                 connection.Close();
    108             }
    109         }
    110     }
    111 }
    欢迎提出意见或建议!!!
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  • 原文地址:https://www.cnblogs.com/gaofei-1/p/7345051.html
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