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C#数据库操作小结

时间：2021-05-01 10:20 编辑：来源：阅读：
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摘要：C#数据库操作小结

[b]1、常用的T-Sql语句 [/b] 查询：SELECT * FROM tb_test WHERE ID='1' AND name='xia' SELECT * FROM tb_test 插入：INSERT INTO tb_test VALUES('xia','123') INSERT INTO tb_test(name) VALUES('xia') 更新：UPDATE tb_test SET password='234' WHERE ID='1' 删除：DELETE FROM tb_test WHERE ID='1' DELETE tb_test WHERE ID='1' [b]2、在vs2010中获取数据库连接字符串 [/b] string connectionString = Properties.Settings.Default.DatabaseTestConnectionString; [b]3、SqlCommand类型 [/b] 查询：

[u]复制代码[/u] 代码如下:

       using (SqlConnection connection = new SqlConnection(connectionString))
       {
             try
             {
                    SqlCommand command = new SqlCommand(selectStr, connection);
                    command.Connection.Open();
                    SqlDataReader reader = command.ExecuteReader();
                     while (reader.Read())
                             label1.Text = "name：" + reader["name"].ToString();    //数据读取
                     command.Connection.Close();
               }
              catch (SqlException ex)
              {
                    throw ex;
              }
       }
       

插入、修改、删除：

[u]复制代码[/u] 代码如下:

       using (SqlConnection connection = new SqlConnection(connectionString))
       {
             try
             {
                    SqlCommand command = new SqlCommand(cmdStr, connection);
                    command.Connection.Open();
                    command.ExecuteNonQuery();
                    command.Connection.Close();
              }
              catch (SqlException ex)
              {
                    throw ex;
              }
      }

[b]4、DataTable类型，查询、添加、修改、删除 [/b] DataTable使用查询、添加、删除、修改时，需要用到SqlDataAdapter类 string selectStr = "SELECT * FROM tb_test2"; 查询：

[u]复制代码[/u] 代码如下:

      using (SqlConnection connection = new SqlConnection(connectionString))
      {
             try
             {
                    SqlDataAdapter adapter = new SqlDataAdapter(selectStr, connection);
                    DataTable dataTable = new DataTable();
                    adapter.Fill(dataTable);
                    //数据读取
                    label1.Text = dataTable.Rows[0][0].ToString();
              }
             catch (SqlException ex)
             {
                     throw ex;
              }
      }
      

添加：

[u]复制代码[/u] 代码如下:

      using (SqlConnection connection = new SqlConnection(connectionString))
      {
           try
           {
                 SqlDataAdapter adapter = new SqlDataAdapter(selectStr, connection);
                 DataTable dataTable = new DataTable();
                 adapter.Fill(dataTable);
                  //添加数据
                 DataRow newRow = dataTable.NewRow();
                 newRow["id"] = "tesr";
                 newRow["name"] = "111";
                 dataTable.Rows.Add(newRow);
                 SqlCommandBuilder builder = new SqlCommandBuilder(adapter);
                 adapter.Update(dataTable); //更新到数据库
            }
            catch (SqlException ex)
            {
                 throw ex;
            }
      }
      

修改：

[u]复制代码[/u] 代码如下:

      using (SqlConnection connection = new SqlConnection(connectionString))
      {
            try
            {
                  SqlDataAdapter adapter = new SqlDataAdapter(selectStr, connection);
                  DataTable dataTable = new DataTable();
                  adapter.Fill(dataTable);
                  //修改数据
                 DataRow updateRow = dataTable.Rows[0];
                 updateRow["id"] = "update";
                 updateRow["name"] = "222";
                 SqlCommandBuilder builder = new SqlCommandBuilder(adapter);
                 adapter.Update(dataTable); //更新到数据库
            }
           catch (SqlException ex)
           {
                 throw ex;
           }
      }
      

删除：

[u]复制代码[/u] 代码如下:

      using (SqlConnection connection = new SqlConnection(connectionString))
      {
            try
            {
                   SqlDataAdapter adapter = new SqlDataAdapter(selectStr, connection);
                   DataTable dataTable = new DataTable();
                   adapter.Fill(dataTable);
                   dataTable.Rows[0].Delete(); //删除记录
                   SqlCommandBuilder builder = new SqlCommandBuilder(adapter);
                   adapter.Update(dataTable); //更新到数据库
             }
            catch (SqlException ex)
            {
                   throw ex;
            }
      }

[b]5、DataSet类型 [/b] DataSet操作跟DataTabel操作基本是一样的，只是DataSet可以储存有多个表格，所以就多做介绍了 [b]6、个人总结 [/b] 个人感觉，用 SqlCommand比较灵活，而DataSet是实现ADO.NET断开式连接的核心，比较安全

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