2015-12-12 16:06 GMT+01:00 Luuk <luuk34 at gmail.com>: > On 12-12-15 15:18, Cecil Westerhof wrote: > >> ?I have the following query: >>> SELECT >>> (SELECT COUNT(*) FROM proverbs) AS Total >>> , (SELECT COUNT(*) FROM proverbs WHERE NOT used IS NULL) AS Used >>> >>> But I want something like: >>> ? SELECT >>> (SELECT COUNT(*) FROM proverbs) AS Total >>> , (SELECT COUNT(*) FROM proverbs WHERE NOT used IS NULL) AS Used >>> , (Total - Used) AS Free >>> ?? >>> ?But then I get: >>> ? no such column: Total >>> >>> It can be done, because I have it done in the past, but obviously a >>> little >>> different. :'-( >>> >>> ?Anybody knows how it can be done?? >>> >>> >> >> SELECT Total, Used, Total-Used as Free >> FROM (SELECT (SELECT COUNT(*) >> FROM proverbs) AS Total , >> (SELECT COUNT(*) FROM proverbs WHERE NOT used IS NULL) AS Used) >> > > or: > select Total, Used, Total-Used as Free from (select count(*) as Total, > count(used) as Used from proverbs) >
?That is what I needed. I prefer the second one. Is probably a little less efficient, but much clearer.? -- Cecil Westerhof
