Mercurial > urweb
diff doc/manual.tex @ 1194:601a77af0477
'AS' clauses for expression columns may be omitted
author | Adam Chlipala <adamc@hcoop.net> |
---|---|
date | Thu, 25 Mar 2010 16:41:51 -0400 |
parents | 1da49fd79e20 |
children | b52929351402 |
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--- a/doc/manual.tex Thu Mar 25 16:27:10 2010 -0400 +++ b/doc/manual.tex Thu Mar 25 16:41:51 2010 -0400 @@ -1959,6 +1959,7 @@ &&& p,^+ & \textrm{particular columns} \\ \textrm{Pre-projections} & p &::=& t.f & \textrm{one column from a table} \\ &&& t.\{\{c\}\} & \textrm{a record of columns from a table (of kind $\{\mt{Type}\}$)} \\ + &&& E \; [\mt{AS} \; f] & \textrm{expression column} \\ \textrm{Table names} & t &::=& x & \textrm{constant table name (automatically capitalized)} \\ &&& X & \textrm{constant table name} \\ &&& \{\{c\}\} & \textrm{computed table name (of kind $\mt{Name}$)} \\ @@ -1997,6 +1998,8 @@ Additionally, an SQL expression may be inserted into normal Ur code with the syntax $(\mt{SQL} \; E)$ or $(\mt{WHERE} \; E)$. Similar shorthands exist for other nonterminals, with the prefix $\mt{FROM}$ for $\mt{FROM}$ items and $\mt{SELECT1}$ for pre-queries. +Unnamed expression columns in $\mt{SELECT}$ clauses are assigned consecutive natural numbers, starting with 1. + \subsubsection{DML} DML commands $D$ are added to the rules for expressions $e$.