Is there any query in Salesforce to fetch all the fields on the entity?

if you are looking for feature like sql select * from table_name then I say no. In salesforce there is no feature like that. And if you want to create a utility class where you can pass the object name and get the all field and prepare soql query with all fields then solution is use decribe call to get the all fields name.

SObjectType accountType = Schema.getGlobalDescribe().get('Account');
Map<String,Schema.SObjectField> mfields = accountType.getDescribe().fields.getMap();