TABLE_CHAT="""DROP TABLE IF EXISTS "chat";CREATE TABLE chat ( chat_id varchar(1000) PRIMARY KEY, user_id int, info text, create_time timestamp(6) DEFAULT current_timestamp, deleted int2);COMMENT ON COLUMN "chat"."chat_id" IS '会话id';COMMENT ON COLUMN "chat"."user_id" IS '会话创建用户id';COMMENT ON COLUMN "chat"."info" IS '会话简介';COMMENT ON COLUMN "chat"."create_time" IS '会话创建时间,默认为当前时间';COMMENT ON COLUMN "chat"."deleted" IS '是否删除:0=否,1=是';COMMENT ON TABLE "chat" IS '会话信息表';"""