Question 16 :
How would you delete a column?
ALTER TABLE techpreparation_answers DROP answer_user_id.
Question 17 :
How would you change a table to InnoDB?
ALTER TABLE techpreparation_questions ENGINE innodb;
Question 18 :
When you create a table, and then run SHOW CREATE TABLE on it, you occasionally get different results than what you typed in. What does MySQL modify in your newly created tables?
1. VARCHARs with length less than 4 become CHARs
2. CHARs with length more than 3 become VARCHARs.
3. NOT NULL gets added to the columns declared as PRIMARY KEYs
4. Default values such as NULL are specified for each column
Question 19 :
How do I find out all databases starting with 'tech' to which I have access to?
SHOW DATABASES LIKE 'tech%';
Question 20 :
How do you concatenate strings in MySQL?
CONCAT (string1, string2, string3)