Her Own First Name

The passenger register files most married women under their husband's name: Maioni, Mrs. Norman (Lucia) is Lucia Maioni, travelling as Mrs. Norman Maioni. When the register knows the woman's own name, it writes it in parentheses. A memorial project wants those names back.

For every passenger whose name contains Mrs. and a name in parentheses, show exactly these 4 columns, in this order:

- passenger_id
- surname — everything before the comma
- own_first_name — the first word inside the parentheses. Usually the parentheses hold one word ((Lucia)); sometimes a full name ((Mary D Kingcome)), and then only Mary is wanted
- husband_first_name — the first word between Mrs. and the opening parenthesis, or NULL when nothing is written there (Hewlett, Mrs. (Mary D Kingcome)) — NULL, not an empty string

Order by passenger_id.

Why this is Hard: nothing here sits at a fixed position. Every cut is an INSTR that finds a marker, and the length of each piece is the distance between two markers. Taking the first word needs a CASE, because INSTR(text, ' ') returns 0 when there is no space — and a SUBSTR whose length works out to -1 returns an empty string without complaint. That empty string is the last trap: it is not NULL, so a report that counts missing husbands with IS NULL would miss every one you leave behind.