markdown sql，update，join

Posted 2021-05-05

## [SQLite] Update with join 
Scenario Desc:
I have 2 table t1, t2. I want to copy t2.author, t2.create_date to t1, how to measure it.

```sql
update 
	test_case
set author=(select case_backup.author from case_backup
	where test_case.file_name=case_backup.file_name),
create_date=(select case_backup.create_date from case_backup
	where case_backup.file_name=test_case.file_name)
where EXISTS (SELECT case_backup.file_name
                  FROM case_backup
                  WHERE case_backup.file_name = test_case.file_name);
```


### Refer
[StackOverflow](https://stackoverflow.com/questions/19270259/update-with-join-in-sqlite)