JdbcTemplate.update（）插入返回值

Question

JdbcTemplate.update() returns number of rows affected - so you not only know that delete/update was sucessfull, you also know how many rows were deleted/updated.

What will be the return value if I try to insert a row.

Is it possible to get return value as "0"??

 private static final String insertSql =
 "INSERT INTO employee (" +
 " name, " +
 " surname, " +
 " title, " +
 " created) " +
 "VALUES (John, Smith, Software developer, new Date())";
 int row = template.update(insertSql, params, types);

Answer 1

是的，理论上你应该得到0或1，但是如果没有插入行，那将是由于一个错误，所以会抛出一个DataAccessException ，这就是你怎么知道出错了什么并且没有创建行的方法。

Answer 2

To answer your question, yes, as @Turophile pointed out, you will get a 0 or 1 in response as you can tell from the method signature (which returns an int).

In response to @Turophile comment (sorry I can't add a comment :/ ), to avoid this and avoid partial data being saved to the database, use Springs Transaction Management (tx). This would allow you to rollback transactions based on specific exceptions or all exceptions from the Exception class. Mind you, by default, @Rollback rolls back transactions for runtime, unchecked exceptions only .

@Transactional(rollbackFor = Exception.class)
public Employee updateEmployee(Employee pEmployee) { ... }

The @Transactional can also be added to the class as well, but I would read up more on it if you are interested in implementing this feature. There is a lot of good documentation on tx.

As a side note, I don't recommend lying to the caller of your method. If you call a method that says "update", run a query that'll update the record, if you want to insert/create a new record, create or call a method that "inserts" a new record into your table -- inserting a duplicate record wouldn't work anyways if the primary key(s) are unique.

Answer 3

jdbctemplate.update will return in integer format as we know. in order to find 0 or 1 just do this below simple code

int i=jdbctemplate.update(.your db call..);

it will return 1 for success and 0 for failure case so, according to it you can process your logic.