CREATE TABLE "defunct_callsigns" (
  "callsign" text,
  "area_served" text,
  "band" text,
  "freq_currently" text,
  "purpose" text
);

Question: What is the Callsign in Brisbane with a Freq currently of 4rph?
SQL: SELECT "callsign" FROM "defunct_callsigns" WHERE "area_served"='brisbane' AND "freq_currently"='4rph';

Question: What is the Freq currently of the 4GG Callsign?
SQL: SELECT "freq_currently" FROM "defunct_callsigns" WHERE "callsign"='4gg';

Question: What is the Community Band with a 4BCB Callsign?
SQL: SELECT "band" FROM "defunct_callsigns" WHERE "purpose"='community' AND "callsign"='4bcb';

Question: What is the Purpose of the Callsign with a Freq currently of 4gld?
SQL: SELECT "purpose" FROM "defunct_callsigns" WHERE "freq_currently"='4gld';

Question: What is the Purpose of the Callsign with a Freq currently of 4rph?
SQL: SELECT "purpose" FROM "defunct_callsigns" WHERE "freq_currently"='4rph';