Mercurial > urweb
changeset 1684:9dd8d47c3e58
Extend and document RANDOM
author | Adam Chlipala <adam@chlipala.net> |
---|---|
date | Sat, 04 Feb 2012 10:42:18 -0500 |
parents | be1ed46d73e2 |
children | 225b87d4a7df |
files | doc/manual.tex src/urweb.grm |
diffstat | 2 files changed, 5 insertions(+), 2 deletions(-) [+] |
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--- a/doc/manual.tex Fri Feb 03 08:30:56 2012 -0500 +++ b/doc/manual.tex Sat Feb 04 10:42:18 2012 -0500 @@ -1848,6 +1848,7 @@ \mt{val} \; \mt{sql\_order\_by\_Nil} : \mt{tables} ::: \{\{\mt{Type}\}\} \to \mt{exps} :: \{\mt{Type}\} \to \mt{sql\_order\_by} \; \mt{tables} \; \mt{exps} \\ \mt{val} \; \mt{sql\_order\_by\_Cons} : \mt{tables} ::: \{\{\mt{Type}\}\} \to \mt{exps} ::: \{\mt{Type}\} \to \mt{t} ::: \mt{Type} \\ \hspace{.1in} \to \mt{sql\_exp} \; \mt{tables} \; [] \; \mt{exps} \; \mt{t} \to \mt{sql\_direction} \to \mt{sql\_order\_by} \; \mt{tables} \; \mt{exps} \to \mt{sql\_order\_by} \; \mt{tables} \; \mt{exps} \\ + \mt{val} \; \mt{sql\_order\_by\_random} : \mt{tables} ::: \{\{\mt{Type}\}\} \to \mt{exps} ::: \{\mt{Type}\} \to \mt{sql\_order\_by} \; \mt{tables} \; \mt{exps} \\ \\ \mt{type} \; \mt{sql\_limit} \\ \mt{val} \; \mt{sql\_no\_limit} : \mt{sql\_limit} \\ @@ -2125,10 +2126,11 @@ Queries $Q$ are added to the rules for expressions $e$. $$\begin{array}{rrcll} - \textrm{Queries} & Q &::=& (q \; [\mt{ORDER} \; \mt{BY} \; (E \; [o],)^+] \; [\mt{LIMIT} \; N] \; [\mt{OFFSET} \; N]) \\ + \textrm{Queries} & Q &::=& (q \; [\mt{ORDER} \; \mt{BY} \; O] \; [\mt{LIMIT} \; N] \; [\mt{OFFSET} \; N]) \\ \textrm{Pre-queries} & q &::=& \mt{SELECT} \; [\mt{DISTINCT}] \; P \; \mt{FROM} \; F,^+ \; [\mt{WHERE} \; E] \; [\mt{GROUP} \; \mt{BY} \; p,^+] \; [\mt{HAVING} \; E] \\ &&& \mid q \; R \; q \mid \{\{\{e\}\}\} \\ - \textrm{Relational operators} & R &::=& \mt{UNION} \mid \mt{INTERSECT} \mid \mt{EXCEPT} + \textrm{Relational operators} & R &::=& \mt{UNION} \mid \mt{INTERSECT} \mid \mt{EXCEPT} \\ + \textrm{$\mt{ORDER \; BY}$ items} & O &::=& \mt{RANDOM} [()] \mid E \; [o] \mid E \; [o], O \end{array}$$ $$\begin{array}{rrcll}