Mercurial > urweb
changeset 440:19d7f79cd584
Time MIN/MAX
| author | Adam Chlipala <adamc@hcoop.net> |
|---|---|
| date | Thu, 30 Oct 2008 15:16:37 -0400 |
| parents | 322c8620bbdf |
| children | c5335613f31e |
| files | lib/top.ur lib/top.urs tests/time.ur |
| diffstat | 3 files changed, 21 insertions(+), 1 deletions(-) [+] |
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--- a/lib/top.ur Thu Oct 30 15:11:37 2008 -0400 +++ b/lib/top.ur Thu Oct 30 15:16:37 2008 -0400 @@ -157,3 +157,11 @@ query q (fn fs _ => return (Some fs)) None + +fun oneRow (tables ::: {{Type}}) (exps ::: {Type}) + (q : sql_query tables exps) [tables ~ exps] = + o <- oneOrNoRows q; + return (case o of + None => error <xml>Query returned no rows</xml> + | Some r => r) +
--- a/lib/top.urs Thu Oct 30 15:11:37 2008 -0400 +++ b/lib/top.urs Thu Oct 30 15:16:37 2008 -0400 @@ -116,3 +116,13 @@ [[nm] ~ acc] => [nm = $fields] ++ acc) [] tables)) + +val oneRow : tables ::: {{Type}} -> exps ::: {Type} + -> sql_query tables exps + -> fn [tables ~ exps] => + transaction + $(exps + ++ fold (fn nm (fields :: {Type}) acc + [[nm] ~ acc] => + [nm = $fields] ++ acc) + [] tables)
--- a/tests/time.ur Thu Oct 30 15:11:37 2008 -0400 +++ b/tests/time.ur Thu Oct 30 15:16:37 2008 -0400 @@ -7,7 +7,9 @@ dml (INSERT INTO t (Id, Time) VALUES (42, {now})); xml <- queryX (SELECT * FROM t) (fn r => <xml>{[r.T.Id]}: {[r.T.Time]}<br/></xml>); + minMax <- oneRow (SELECT MIN(t.Time) AS Min, MAX(t.Time) AS Max FROM t); return <xml><body> {xml} - {[now]}, {[now = now]}, {[now = later]}, {[later < now]}, {[now < later]} + {[now]}, {[now = now]}, {[now = later]}, {[later < now]}, {[now < later]}<br/> + {[minMax.Min]}, {[minMax.Max]} </body></xml>