CREATE TABLE "managerial_changes" (
  "team" text,
  "outgoing_manager" text,
  "manner_of_departure" text,
  "date_of_vacancy" text,
  "replaced_by" text,
  "date_of_appointment" text,
  "position_in_table" text
);

Question: What is the date of vacancy when the date of appointment is 28 november 2007 and replaced by is alex mcleish?
SQL: SELECT "date_of_vacancy" FROM "managerial_changes" WHERE "date_of_appointment"='28 November 2007' AND "replaced_by"='Alex McLeish';

Question: What is the date of appointment when the date of vacancy is 21 december 2007?
SQL: SELECT "date_of_appointment" FROM "managerial_changes" WHERE "date_of_vacancy"='21 December 2007';

Question: Who replaced when team is wigan athletic?
SQL: SELECT "replaced_by" FROM "managerial_changes" WHERE "team"='Wigan Athletic';

Question: What is the date of vacancy when the team is manchester city and replaced by is mark hughes?
SQL: SELECT "date_of_vacancy" FROM "managerial_changes" WHERE "team"='Manchester City' AND "replaced_by"='Mark Hughes';

Question: What is the date of appointment when replaced by is roy hodgson?
SQL: SELECT "date_of_appointment" FROM "managerial_changes" WHERE "replaced_by"='Roy Hodgson';

Question: Who replaced when position in table is pre-season?
SQL: SELECT "replaced_by" FROM "managerial_changes" WHERE "position_in_table"='Pre-season';