MySQL，根据日期列选择行

Question

I have a table with two columns, like:

X         Date
A         2017-08-10
B         2016-12-19         
C         2017-06-13
D         2017-07-20
E         2017-07-14

I would like to avoid selecting data which is more than one week older than the data in a row with X=D. I tried some queries:

SELECT * FROM table WHERE Date < (SELECT Date FROM table where X='D') - INTERVAL 1 WEEK

but it isn't work for me. The output should be like:

X         Date
A         2017-08-10
D         2017-07-20
E         2017-07-14

I'm close to solve this problem I think but a little help can be significant for me.

Answer 1

Here's a fish

SELECT x.* 
  FROM my_table x
  JOIN my_table y
    ON y.date - INTERVAL 1 WEEK < x.date
   AND y.x = 'd';

Answer 2

SELECT * FROM table WHERE
Date > (SELECT DATE_SUB(Date, INTERVAL 7 DAY)  FROM table where X='D')

or

SELECT * FROM table
WHERE Date > (SELECT DATE_SUB(Date, INTERVAL 1 WEEK)  FROM table where X='D')

You can check here SQL Fiddle Demo

Try above query.