19 разбор

A) ALTER TABLE students ADD COLUMN ROW email VARCHAR(50);

B) ALTER TABLE students MODIFY COLUMN email VARCHAR(50);

C) ALTER TABLE students ADD email VARCHAR(50)

D) ALTER TABLE students CHANGE COLUMN email VARCHAR(50);

A) ALTER TABLE students DELETE favorite_subject;

B) ALTER TABLE students REMOVE COLUMN favorite_subject;

C) ALTER TABLE students DROP COLUMN favorite_subject;

D) ALTER students DROP ROW favorite_subject;

A) DELETE FROM students;

B) DROP TABLE students;

C) TRUNCATE TABLE students;

D) CLEAR TABLE students;

A) age | SUM(id)

-------------

16 | 27

17 | 22

B) age | SUM(id)

-------------

16 | 37

17 | 22

C) age | SUM(id)

-------------

16 | 37

17 | 22

18 | 10

19 | 15

D) age | SUM(id)

-------------

16 | 17

17 | 19

A)| category | sum(quantity * price) |

|--------------|------------------------|

| Electronics | 1900 |

| Clothing | 300 |

B) | category | sum(quantity * price) |

|--------------|------------------------|

| Electronics | 1900 |

C) | category | sum(quantity * price) |

|--------------|------------------------|

| (Пусто) | (Пусто) |

D) | category | sum(quantity * price) |

|--------------|------------------------|

| Electronics | 1000 |

| Clothing | 1000 |