一个很好用的DBHelper类(包括使用SQL语句 存储过程 事务 做相关操作) 入门级

话不多少 直接贴代码

 

需引入的命名空间

需引入的命名空间

 

定义连接属性

SQL连接对象

 1 private  SqlConnection conn;
 2         public  SqlConnection Conn 
 3         {
 4             get 
 5             {
 6                 if (conn == null)
 7                 {
 8                     string connStr = ConfigurationManager.ConnectionStrings["connStr"].ConnectionString;
 9                     conn = new SqlConnection(connStr);
10                 }
11                 if (conn.State == ConnectionState.Closed)
12                     conn.Open();
13                 if (conn.State == ConnectionState.Broken)
14                 {
15                     conn.Close();
16                     conn.Open();
17                 }
18                 return conn; 
19             }
20         }

做查询(包括sql语句和带参数的SQL语句)

查询

 1   //查询:DataReader
 2         public  SqlDataReader GetReader(string sql)
 3         {
 4            SqlCommand cmd = new SqlCommand(sql, Conn);
 5            return cmd.ExecuteReader(CommandBehavior.CloseConnection);
 6         }
 7         public  SqlDataReader GetReader(string sql,SqlParameter[] paras)
 8         {
 9             SqlCommand cmd = new SqlCommand(sql, Conn);
10             cmd.Parameters.AddRange(paras);
11             return cmd.ExecuteReader(CommandBehavior.CloseConnection);
12         }
13 
14         //查询:DataTable
15         public DataTable GetTable(string sql)
16         {
17             SqlDataAdapter dap = new SqlDataAdapter(sql, Conn);
18             DataTable dt = new DataTable();
19             dap.Fill(dt);
20             conn.Close();
21             return dt;
22         }
23         public DataTable GetTable(string sql, SqlParameter[] paras)
24         {
25             SqlCommand cmd = new SqlCommand(sql, Conn);
26             cmd.Parameters.AddRange(paras);
27             SqlDataAdapter dap = new SqlDataAdapter(cmd);
28             DataTable dt = new DataTable();
29             dap.Fill(dt);
30             conn.Close();
31             return dt;
32 
33         }

 

做增删改(包括sql语句和带参数的SQL语句)

增删改

 1 //增改删
 2         public bool ExecuteNoQuery(string sql)
 3         {
 4             SqlCommand cmd = new SqlCommand(sql, Conn);
 5             int result = cmd.ExecuteNonQuery();
 6             this.conn.Close();
 7             return result > 0;
 8         }
 9         public bool ExecuteNoQuery(string sql, SqlParameter[] paras)
10         {
11             SqlCommand cmd = new SqlCommand(sql, Conn);
12             cmd.Parameters.AddRange(paras);
13             int result = cmd.ExecuteNonQuery();
14             this.conn.Close();
15             return result > 0;
16         }

 

执行聚合函数(包括sql语句和带参数的SQL语句)

执行聚合函数

 1         //执行聚合函数
 2         public object ExecuteScalar(string sql)
 3         {
 4             SqlCommand cmd = new SqlCommand(sql, Conn);
 5             object result = cmd.ExecuteScalar();
 6             this.conn.Close();
 7             return result;
 8         }
 9         public object ExecuteScalar(string sql, SqlParameter[] paras)
10         {
11             SqlCommand cmd = new SqlCommand(sql, Conn);
12             cmd.Parameters.AddRange(paras);
13             object result = cmd.ExecuteScalar();
14             this.conn.Close();
15             return result;
16         }

 执行存储过程获取数据集(包括sql语句和带参数的SQL语句)

 

执行存储过程获取数据集(查询)

 1  //执行存储过程获取数据集(查询)
 2         public DataTable ExecuteProcSelect(string ProcName, SqlParameter[] paras)
 3         {
 4             SqlCommand cmd = new SqlCommand(ProcName, Conn);
 5             cmd.Parameters.AddRange(paras);
 6             cmd.CommandType = CommandType.StoredProcedure;
 7             SqlDataAdapter dap = new SqlDataAdapter(cmd);
 8             DataTable dt = new DataTable();
 9             dap.Fill(dt);
10             this.conn.Close();
11             return dt;       
12         }

 

执行存储过程做增删改

执行存储过程做增删改

 1 //执行存储过程做增删改
 2  public bool ExecuteProcUpdate(string ProcName, SqlParameter[] paras)
 3         {
 4             SqlCommand cmd = new SqlCommand(ProcName, Conn);
 5             cmd.Parameters.AddRange(paras);
 6             cmd.CommandType = CommandType.StoredProcedure;
 7             int result = cmd.ExecuteNonQuery();
 8             this.conn.Close();
 9             return result > 0;
10         }

执行事物(ADO.NET)

执行事物(ADO.NET)

 1    //执行事物(ADO.NET)
 2         public bool ExecuteTrasaction(string sqlStr, string TranName)
 3         {
 4             bool result = true;
 5             SqlTransaction tran = null;
 6             try
 7             {
 8                 tran = Conn.BeginTransaction(TranName);
 9                 SqlCommand cmd = new SqlCommand(sqlStr, Conn, tran);
10                 int n = cmd.ExecuteNonQuery();
11                 if (n > 0)
12                 {
13                     tran.Commit();
14                     result = true;
15                 }
16                 else
17                 {
18                     tran.Rollback();
19                     result = false;
20                 }
21             }
22             catch
23             {
24                 tran.Rollback();
25                 result = false;
26             }
27             return result;
28         }

本文完...