SQL delete from a table where a value is true in other table

I need to write an sql with the below requirements..

1. I have a table A with column AA in it.
2. I have another table B with column BB in it.
3. Column A in table A开发者_开发问答A will have only two values ..

   either 0 or 100 and column column BB in table B has only one value either 1 or 2 or 3....or 7 and this value represents the daynumber in a week and so will change daily in order or Monday(value=0) to Sunday(value=7)..Please ignore the content in comments./* BB in table b has values from 1 through 7.*/

   There is no column common between A and B tables

Now, I need to delete table A where AA = 100... but this should happen only when column BB = 7.

Can anyone help me out to write SQL for the above.

The statement below will delete all rows from a where aa is equal to 100, only if there exists one or more rows in b where bb is equal to 7.

delete from a where aa = 100 and exists (select * from b where bb = 7);  

See check this if you want like this.

create table A (AA int)
create table B (BB int)

insert into A values (100)
insert into B values (1)

--Invalid Case
if exists (select 1 from B where BB = 7)
begin
    delete from A where aa = 100
    if @@rowcount > 0
    begin
        print 'BB in B has value euqal to 7'
    end
end
else
    begin
        print 'BB in B not equals to 7'
    end

--Valid Case
update B set BB = 7
if exists (select 1 from B where BB = 7)
begin
    delete from A where aa = 100
    if @@rowcount > 0
    begin
        print 'BB in B has value euqal to 7'
    end
end
else
    begin
        print 'BB in B not equals to 7 and Data Deleted from A'
    end