Compare the time of two tables and take all data larger than a certain time

A table A1 field is a Time field
b table B1 field is Time field

Two table association fields uid,a to user table, B to data table

The time data format is 0000-00-00 00:00:00

A UID time for the A1 field is a fixed time
B1 field is more than one variable time

Compare all data contents of B1 that UID is greater than A1 time, and remove all data larger than A1 if it is greater than B1.

How do I write this? Thanks, man.

Reply to discussion (solution)

has been done, more than one query SQL in contrast, but have not found a better way.

SELECT * from B LEFT join A on B.uid=a.uid where b.b1 > a.a1

SELECT * from B LEFT join A on B.uid=a.uid where b.b1 > a.a1

Later it is changed to this, but query the UID of the next level of data, can only be queried once, and then contrast. Thank you for it!

