Common operations of db2

Common operations of db2

Description: This blog is an accumulation of daily knowledge points and will be updated from time to time. If you don't like it, don't spray it. Of course, I hope it can help you

create a table.

DROP TABLE T_PATRON_INFO;

CREATE TABLE T_PATRON_INFO (
  USER_ID        INTEGER       GENERATED ALWAYS AS IDENTITY (START WITH 1 INCREMENT BY 1),
  UAER_NM	     VARCHAR(16)   NOT NULL DEFAULT ,
  ROW_CRT_TS	 TIMESTAMP 	   NOT NULL DEFAULT ,
  primary key(USER_ID)
)

The sequence operation
creates a sequence

CREATE SEQUENCE  T_PATRON_INFO_SEQUENCE  AS INT START WITH 1 INCREMENT BY 1 MINVALUE 1 NO MAXVALUE NO CYCLE NO CACHE ORDER;

CREATE SEQUENCE  T_PATRON_INFO_SEQUENCE1  START WITH 1 INCREMENT BY 1 NOMAXVALUE NOCYCLE CACHE 24;

Query sequence (use prevval to get the current value and nextval to the next value)

select nextval for T_PATRON_INFO_SEQUENCE from sysibm.sysdummy1

select nextval for T_PATRON_INFO_SEQUENCE from T_PATRON_INFO;

delete sequence

DROP SEQUENCE T_PATRON_INFO_SEQUENCE   ;

Operation operation timestamp, the time below TIMESTAMP (db2 insert time (date) type)

can also be defined as 2016-10-26 22:22:22
You can also use a function instead of current timestamp

INSERT INTO T_PATRON_INFO(UAER_NM,ROW_CRT_TS) values ('patronli','2016-10-26');

add field

ALTER TABLE t_patron_info ADD COLUMN sp_cd CHAR(6);

Modify fields

ALTER TABLE t_patron_info ALTER sp_cd SET DATA TYPE DECIMAL(3);

db2 groups by date (date to character) (but to-char is not supported in lower versions of db2)

to_char(row_crt_ts,'YYYY-MM') as transDate,count(0) as num from T_patronli_info  group by to_char(row_crt_ts,'YYYY-MM')

Common operations of db2

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