c# - Reader for a MySqLConnection without database parameter in Connection String -

i'm trying run following query via datareader on mysql instance. reader returns null , understand due missing database parameter in connection string. how query work. need username, database name , hostname database i'm not sure database query same.

select current_user(), database(), @@hostname hostname; 

the call made in following function , connection not specific database:

public databasedetails getdetailsdetails(connectiondetails details)     {         using (var dbcommand = details.connection.createcommand())         {             dbcommand.commandtext = "select current_user(), database(), @@hostname hostname;";             using (var dr = dbcommand.executereader(commandbehavior.singlerow))             {                 return dr.read()                     ? new databasedetails                     {                         username = dbfunction.getstring(dr, 0),                         database = dbfunction.getstring(dr, 1),                         server = dbfunction.getstring(dr, 2)                     }                     : null;             }         }     } 

connection string used:

user id=root;password=***;data source=localhost;integrated security=false;auto enlist=true; 

additional information: i'm not able top 20 records database table when put database name within query. datareader on debug shows rows of them "?". example following commandtext, no records:

select * db_sample.table_sample limit 20; 

update: have worked way pull data table when database mentioned either in query or in connection string. need following mysql data server without knowing database (using query):

• database name
• host name
• user name