PostgreSQL Exam PGCES-02 Topic 1 Question 37 Discussion

The table "custom" is defined below. The "id" column and "introducer" column are of

INTEGER type, and the "email" column is of TEXT type.

id | email | introducer ----+-- ---------------+-----------2 |

aaa@example.com | 1 3 |

bbb@example.com | 2 4 |

ccc@example.com | 2

Three SQL statements were executed in the following order:

UPDATE custom SET email = '' FROM custom c WHERE

custom.introducer = c.id; UPDATE custom SET introducer = NULL

WHERE introducer NOT IN (SELECT id FROM custom); DELETE

FROM custom WHERE id = 2 OR introducer = 2; Select the number of rows in the "custom" table after the execution.