C#读取appconfig文件配置数据库连接并 连接数据库进行数据查询

App.config配置如下：

<?xml version="1.0" encoding="utf-8"?>
<configuration>
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.7.2" />
</startup>
<!--数据库配置1-->
<connectionStrings>
<!--<add name="MyContext" providerName="MySql.Data.MySqlClient" connectionString="server=192.168.32.146; port=3306;database=jd_autotest;uid=root;password=123456" />-->
<add name="MyContext" providerName="MySql.Data.MySqlClient" connectionString="server=192.168.32.146;user=root;database=jd_autotest;port=3306;password=123456;allow user variables=true;CharSet=utf8;SslMode=None;"/>
</connectionStrings>

<appSettings>
<add key="MyConnectContext" value="server=192.168.32.146; port=3306;uid=root;password=123456;database=jd_autotest;" />
</appSettings>

</configuration>

主要数据库操作：

获取配置方法一：

string ConnectString = System.Configuration.ConfigurationManager.ConnectionStrings["MyContext"].ToString();

获取配置方法二：

string  ConnectString = ConfigurationManager.AppSettings["MyConnectContext"].ToString();

1.连接数据库并查询获取数据：

       public DataTable searchData(string band)
        {
            MySqlConnection mySqlConnection = new MySqlConnection(ConnectString);
            string sqlJoin = "";

            if (!band.Equals(""))
            {
                sqlJoin = " where band.band  in  ('" + band + "')";
            }

            string querySql = string.Format(@"select * from band {0}", sqlJoin);

            MySqlCommand mySqlCommand = new MySqlCommand(querySql, mySqlConnection);
            mySqlCommand.CommandTimeout = 180;
            MySqlDataAdapter mySqlDataAdapter = new MySqlDataAdapter();
            mySqlDataAdapter.SelectCommand = mySqlCommand;
            DataTable dataTable = new DataTable("band");
            mySqlDataAdapter.Fill(dataTable);

            return dataTable;
        }

2.更新数据库数据：

    public  void  UpdateTestData(string result,string value1,string value2,string value3,string limit1,string limit2,string limit3,string test_data_id)
        {
            try
            {
                int successCount = 0;
                DataTable dtTestUpdateData = new DataTable();                
                MySqlConnection myConn = Db.MyConn();
                MySqlTransaction tran = myConn.BeginTransaction();
                try
                {
                    MySqlDataAdapter ada = new MySqlDataAdapter();
                    string UpDateSql = string.Format(@"update test_data
                        set
                        result = ifnull(@result, ''),
                        limit1 = ifnull(@limit1, ''),
                        limit2 = ifnull(@limit2, ''),
                        limit3 = ifnull(@limit3, ''),
                        value1 = ifnull(@value1, ''),
                        value2 = ifnull(@value2, ''),
                        value3 = ifnull(@value3, ''),
                        modify_user_name = ifnull(@modify_user_name, ''),
                        modify_datetime = now()
                    where test_data_id = @test_data_id");

                    MySqlCommand updateCommand = new MySqlCommand(UpDateSql, myConn);
                    updateCommand.Parameters.AddWithValue("result", result);
                    updateCommand.Parameters.AddWithValue("limit1", limit1);
                    updateCommand.Parameters.AddWithValue("limit2", limit2);
                    updateCommand.Parameters.AddWithValue("limit3", limit3);
                    updateCommand.Parameters.AddWithValue("value1", value1);
                    updateCommand.Parameters.AddWithValue("value2", value2);
                    updateCommand.Parameters.AddWithValue("value3", value3);
                    updateCommand.Parameters.AddWithValue("modify_user_name", MyHelper.loginUserName);
                    updateCommand.Parameters.AddWithValue("test_data_id", test_data_id);
                    successCount = updateCommand.ExecuteNonQuery();
                    tran.Commit();
                }
                catch (Exception ex)
                {                   
                }
                
            }
            catch (Exception ex)
            {

            }                
        }

 注意事项：

引用 ConfigurationManager 需添加 using System.Configuration;引用，  路径一般在 C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.7.2\System.Configuration.dll中。

引用 MySqlConnection  需添加 using System.Data;