sql - 在 DB2 中更改主键序列( 'Default' 到 'Always')

Question

我在 DB2 中创建了下表。由于序列是GENERATED BY DEFAULT，主键可以插入表中(因为主键是在使用alter创建表后添加的)并且存在重复值的机会。解决方案是使用 GENERATED BY ALWAYS 创建序列。现在我的表中有数据，我想将其从 GENERATED BY DEFAULT 更改为 GENERATED BY ALWAYS

  CREATE TABLE HW_COB.ILCCDS 
  ( 
                   CDS_IDENTITY FOR COLUMN CDSID NUMERIC(13, 0) GENERATED BY DEFAULT AS IDENTITY ( 
                   START WITH 1 INCREMENT BY 1 
                   NO MINVALUE NO MAXVALUE 
                   NO CYCLE NO ORDER 
                   CACHE 20 ) ,

CODE_1 FOR COLUMN CDSCD1 CHAR(30),
CODE_2 FOR COLUMN CDSCD2 CHAR(30) );
ALTER TABLE HW_COB.ILCCDS ADD CONSTRAINT HW_COB.PK_CDS_IDENTITY PRIMARY KEY (CDS_IDENTITY);

Answer 1

Finally got the alter as :

ALTER TABLE HW_COB.ILCCDS ALTER COLUMN CDS_IDENTITY SET GENERATED ALWAYS;