执行alter table以添加具有默认值seq.nextval的新列时出错

Question

我在使用Oracle 11g执行以下sql查询时遇到错误

ALTER TABLE table add column_col integer DEFAULT table_seq.nextval not null;

Error report -
ORA-00984: column not allowed here
00984. 00000 -  "column not allowed here"

Answer 1

该语法不适用于11g。这是12的新功能。你需要一个触发器：

CREATE OR REPLACE TRIGGER "TRIGGERNAME" BEFORE INSERT ON <<TABLENAME>>
FOR EACH ROW
 WHEN (new."COLUMNNAME" IS NULL) 
BEGIN
  SELECT table_seq.nextval
  INTO :new."COLUMNNAME" 
  FROM dual;
END;
/