Create sequence postgresql

gistfile1.sql

DROP SEQUENCE chat_id_seq
CREATE SEQUENCE chat_id_seq;
DROP TABLE "chat";
CREATE TABLE "chat" (
	"id" int4 NOT NULL DEFAULT nextval('chat_id_seq'),
	"text" text,
	"installation_object_id" varchar(256),
	"created_at" date,
	"updated_at" date,
	"account_name" text,
	"device_id" varchar(256)
)
WITHOUT OIDS;
ALTER TABLE "chat" OWNER TO "postgres";

ALTER TABLE "chat" ADD CONSTRAINT "chat_pkey" PRIMARY KEY ("id");