    here is field name of table.
    student_score: name, chinese, math, english, total_score
    student_gender:  name, gender, class
    
    user commands: 
    Please provide an SQL command and perform the following actions:
1. Merge database tables' student_score 'and' student_gender ' by ' name '
2. Find the student_ Everyone with a class of 1,2 and a gender of boy in gender
3. And calculate the average value of 'total_score' from the student_score Please reply with exactly 4 paragraphs and separate each paragraph with two new lines. The very first paragraph must start with the word "detect".
user