我有这个数据补丁。
ALTER TABLE MY_TABLE ADD new_id number;
DECLARE
MAX_ID NUMBER;
BEGIN
SELECT max(id) INTO MAX_ID FROM some_table;
EXECUTE IMMEDIATE 'CREATE sequence temp_seq start WITH ' || MAX_ID || ' increment by 1';
UPDATE MY_TABLE SET new_id = temp_seq.nextval;
EXECUTE IMMEDIATE 'DROP sequence temp_seq';
END;
/
这给我
UPDATE MY_TABLE SET new_id = temp_seq.nextval;
*
ERROR at line 8:
ORA-06550: line 8, column 40:
PL/SQL: ORA-02289: sequence does not exist
ORA-06550: line 8, column 3:
PL/SQL: SQL Statement ignored
但如果我把更新移到外面,就可以了。
DECLARE
MAX_ID NUMBER;
BEGIN
SELECT max(id) INTO MAX_ID FROM some_table;
EXECUTE IMMEDIATE 'CREATE sequence temp_seq start WITH ' || MAX_ID || ' increment by 1';
END;
/
UPDATE MY_TABLE SET new_id = temp_seq.nextval;
我可以用第二种方法 但我很好奇为什么在区块内更新会失败 谢谢你的帮助。
因为在编译时,这个序列并不存在。如果你想在PLSQL块中使用它,你就必须这样做。动态就像你创建序列一样