CREATE TABLE table_203_156 (id DECIMAL, "team" TEXT, "outgoing manager" TEXT, "manner of departure" TEXT, "date of vacancy" TEXT, "replaced by" TEXT, "date of appointment" TEXT, "position in table" TEXT)

which manager has the earliest date of appointment ?
SELECT "outgoing manager" FROM table_203_156 ORDER BY "date of appointment" LIMIT 1
SELECT "outgoing manager" FROM "table_203_156" ORDER BY "date of appointment" NULLS FIRST LIMIT 1