Learn MYSQL MCQs
Prepare MYSQL MCQs (Multiple choice Questions) for exam and job interviews.
Which SQL command is used to back up a MySQL database?
1) BACKUP DATABASE database_name;
2) mysqldump database_name;
3) EXPORT DATABASE database_name;
4) SAVE DATABASE database_name;
Answer : Option 2
What is the purpose of the SQL DISTINCT keyword?
1) To return unique values
2) To sort values
3) To limit results
4) To group values
Answer : Option 1
How do you create a trigger in MySQL?
1) CREATE TRIGGER trigger_name;
2) ADD TRIGGER trigger_name;
3) DEFINE TRIGGER trigger_name;
4) NEW TRIGGER trigger_name;
Answer : Option 1
Which function is used to find the total number of characters in a string?
1) LEN()
2) COUNT()
3) LENGTH()
4) CHAR_LENGTH()
Answer : Option 3
What is a foreign key in MySQL?
1) A key used to link two tables together
2) A key that uniquely identifies a record
3) A key that cannot be NULL
4) A primary key of another table
Answer : Option 1
How do you change the data type of an existing column in MySQL?
1) ALTER TABLE table_name MODIFY column_name new_data_type;
2) ALTER TABLE table_name CHANGE column_name new_data_type;
3) CHANGE COLUMN column_name TO new_data_type;
4) MODIFY TABLE table_name CHANGE column_name new_data_type;
Answer : Option 1
Which command is used to remove a column from a MySQL table?
1) ALTER TABLE table_name DROP COLUMN column_name;
2) REMOVE COLUMN column_name FROM table_name;
3) DELETE COLUMN column_name FROM table_name;
4) CLEAR COLUMN column_name IN table_name;
Answer : Option 1
What is the maximum length of a VARCHAR column in MySQL?
1) 255 characters
2) 65,535 characters
3) 16,383 characters
4) 1,000 characters
Answer : Option 2
Which command is used to import data from a file into a MySQL table?
1) LOAD DATA INFILE
2) IMPORT FILE
3) INSERT FROM FILE
4) UPLOAD FILE
Answer : Option 1
How do you create an index on a column in MySQL?
1) CREATE INDEX index_name ON table_name (column_name);
2) ADD INDEX index_name TO table_name (column_name);
3) SET INDEX index_name FOR table_name (column_name);
4) DEFINE INDEX index_name IN table_name (column_name);
Answer : Option 1