explain a select statement

[dumdum2]

Can someone explain what this select statement means...?

SELECT [dates and wl].*, (select top 1 rsvid FROM [Dates and wl] b where b.studio=[Dates and wl].studio and b.res_begin>=[Dates and wl].res_end order by b.res_begin) AS nextrsvid
FROM [dates and wl];


What is 'b' ?

Thanks!

 

[PHV]

b is an alias for the 2nd instance of the [Dates and wl] table.

Hope This Helps, PH.
Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884 or FAQ181-2886

 

[lespaul]

it allows for a correlated sub query (a subquery that is related to the "main" query).

SELECT (all the fields from [dates and wl])
and
(the field RSVID from the same table where the studio matches the outer query and the res_begin is greater than res_end: name this field nextRSVID)

HTH
Leslie