Significant differences between Oracle and Postgresql in PLSQL transaction rollback

相关
《Oracle/Mysql迁移到PostgresqlTransaction rollback behavior differences and transformation methods》
《Oracle与Postgresql在PLSQLSignificant difference in internal transaction rollback》

This difference is very easy to makeOracle迁移到PGThere is a major difference in the business logic after that.

1 总结

先放总结

• Oracle：在PLSQLInside if statement execution fails,After entering the exception handler,PL程序正常退出.Then before the execution of the failed statementSQL不会回滚,The execution results are submitted normally.
• Postgresql：在PLPGSQLInside if statement execution fails,After entering the exception handler,PL正常退出.那么整个PL内的所有SQL自动回滚,因为：
  • PG不支持PL内写SAVEPOINT （OracleThere is an implicit before each statementsavepoint）
  • PLThe whole is packaged in one big transaction.

Oracle11g

https://docs.oracle.com/cd/E11882_01/appdev.112/e25519/static.htm#LNPLS598

2 测试用例Oracle11g

drop table employees;
create table employees(employee_id int, salary int, raise int, job_id varchar(16), last_name varchar(16), first_name varchar(16));
insert into employees values (1, 1000, 60, 'ST_CLERK', 'Geller', 'Rose');
insert into employees values (2, 2000, 100, 'ST_CLERK', 'Green', 'Rachel');
insert into employees values (3, 4000, 400, 'ST_AAAAA', 'Bing', 'Chanller');
insert into employees values (4, 6000, 630, 'AD_CLERK', 'Geller', 'Rose');
insert into employees values (5, 7000, 120, 'AD_DSFWR', 'Green', 'Rachel');
insert into employees values (6, 8000, 410, 'AD_AAAAA', 'Bing', 'Chanller');
DROP TABLE emp_name;
CREATE TABLE emp_name AS SELECT employee_id, last_name, salary FROM employees;
CREATE UNIQUE INDEX empname_ix ON emp_name (employee_id);
 
DECLARE
  emp_id        employees.employee_id%TYPE;
  emp_lastname  employees.last_name%TYPE;
  emp_salary    employees.salary%TYPE;
 
BEGIN
  SELECT employee_id, last_name, salary
  INTO emp_id, emp_lastname, emp_salary 
  FROM employees
  WHERE employee_id = 1;
  INSERT INTO emp_name (employee_id, last_name, salary) VALUES (100, emp_lastname, emp_salary);
  INSERT INTO emp_name (employee_id, last_name, salary) VALUES (emp_id, emp_lastname, emp_salary);
  
EXCEPTION
  WHEN DUP_VAL_ON_INDEX THEN
  DBMS_OUTPUT.PUT_LINE('Insert was rolled back');
END;
/


select * from emp_name;

结果

3 测试用例Postgresql14

drop table employees;
create table employees(employee_id int, salary int, raise int, job_id varchar(16), last_name varchar(16), first_name varchar(16));
insert into employees values (1, 1000, 60, 'ST_CLERK', 'Geller', 'Rose');
insert into employees values (2, 2000, 100, 'ST_CLERK', 'Green', 'Rachel');
insert into employees values (3, 4000, 400, 'ST_AAAAA', 'Bing', 'Chanller');
insert into employees values (4, 6000, 630, 'AD_CLERK', 'Geller', 'Rose');
insert into employees values (5, 7000, 120, 'AD_DSFWR', 'Green', 'Rachel');
insert into employees values (6, 8000, 410, 'AD_AAAAA', 'Bing', 'Chanller');
DROP TABLE emp_name;
CREATE TABLE emp_name AS SELECT employee_id, last_name, salary FROM employees;
CREATE UNIQUE INDEX empname_ix ON emp_name (employee_id);
select * from emp_name;

DO $$DECLARE
  emp_id        employees.employee_id%TYPE;
  emp_lastname  employees.last_name%TYPE;
  emp_salary    employees.salary%TYPE;
 
BEGIN
  SELECT employee_id, last_name, salary
  INTO emp_id, emp_lastname, emp_salary 
  FROM employees
  WHERE employee_id = 1;
  INSERT INTO emp_name (employee_id, last_name, salary) VALUES (100, emp_lastname, emp_salary);
  INSERT INTO emp_name (employee_id, last_name, salary) VALUES (emp_id, emp_lastname, emp_salary);
  
EXCEPTION
  WHEN others THEN
  raise notice 'Insert was rolled back';
END$$;
select * from emp_name;

执行结果