ALTER TABLE "mailbox"."mail"
    ADD COLUMN "extension_request_id" varchar(20);

COMMENT ON COLUMN "mailbox"."mail"."extension_request_id" IS '申请延期ID';

ALTER TABLE "mailbox"."mail_extension_approval"
    ADD COLUMN "request_id" varchar(20);

COMMENT ON COLUMN "mailbox"."mail_extension_approval"."request_id" IS '申请延期ID';