CREATE TABLE "table1_25740548_2" (
  "series_num" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "production_code" text,
  "u_s_viewers_million" text
);

Question: How many episodes with the production code CA106 are there?
SQL: SELECT COUNT("written_by") FROM "table1_25740548_2" WHERE "production_code"='CA106';

Question: Who was the director for episodes that were written be Matthew Lau?
SQL: SELECT "directed_by" FROM "table1_25740548_2" WHERE "written_by"='Matthew Lau';

Question: How many episode were written by Brett Conrad?
SQL: SELECT COUNT("title") FROM "table1_25740548_2" WHERE "written_by"='Brett Conrad';

Question: How many episodes were directed by Tim Matheson?
SQL: SELECT COUNT("original_air_date") FROM "table1_25740548_2" WHERE "directed_by"='Tim Matheson';

Question: How many episodes were directed by Rod Hardy?
SQL: SELECT COUNT("original_air_date") FROM "table1_25740548_2" WHERE "directed_by"='Rod Hardy';