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我学习SQL和考试准备的问题有一个用户会话,像这样:说明为什么以下SQL ROLLBACK命令会导致错误?
CREATE TABLE product (pcode NUMBER(2), pname VARCHAR2(10));
INSERT INTO product VALUES (1, 'pen');
INSERT INTO product VALUES (2, 'pencil');
SAVEPOINT a;
UPDATE product SET pcode = 10 WHERE pcode = 1;
SAVEPOINT b;
DELETE FROM product WHERE pcode = 2;
COMMIT;
SQL> DELETE FROM product WHERE pcode = 10;
以上之后,我们运行这个命令:
ROLLBACK TO SAVEPOINT a
根据测试-guide ,这会产生一个错误;也 - 没有SQL语句回滚。
这是为什么?
其中是回滚命令?也是 - 这是预言吗? – benji
@benji - 谢谢,添加了一个缺失的细节 – Coffee