Question: I am trying to get one week earlier then current week of the year but my sql query is returning null. here is my query

```
select date_sub(yearweek('2014-01-01'),INTERVAL 1 week)

```

what is wrong with this query

Answer: 
If you want to get `YEARWEEK` of week prior to date, you can do this:
Note: `YEARWEEK` results in 6-digit number, first 4 digits are week year, trailing 2 digits are week number.

```
SELECT YEARWEEK('2014-01-01' - INTERVAL 1 WEEK)

```

If you need to get a `date` that is one week before a given date, then:

```
SELECT '2014-01-01' - INTERVAL 1 WEEK

```
Try this

```
select date_sub(date('2014-01-01'),INTERVAL 1 week)

```