[r2005-04-24 18:07:07 by cmiachon] modifying queries + or -> || + adding .. + correcting typos

Original author: cmiachon
Date: 2005-04-24 18:07:07+00:00

web/tutorial/queries.xml

@@ -239,7 +239,7 @@ let sel = select y
           from x in [bib]/<paper>_ ,
                y in [x]/<title>_,
                z in [x]/<author>_
-where z = <author>"Alain Frisch" or z = <author>"Veronique Benzaken"
+where ((z = <author>"Alain Frisch") || (z = <author>"Veronique Benzaken"));;
 ]]>
 </sample>
 <p> Which yields: </p>
@@ -272,8 +272,8 @@ any XPath-like projections)
 
 <sample><![CDATA[
 let sel = select t
-from <_>[(x::<paper>_ | _ )*] in [bib],
-     <_>[ _* (<author>"Alain Frisch" | <author>"Veronique Benzaken")  _*  (t&<title>_ ); _]  in x  
+from <_ ..>[(x::<paper>_ | _ )*] in [bib],
+     <_ ..>[ _* (<author>"Alain Frisch" | <author>"Veronique Benzaken")  _*  (t&<title>_ ); _]  in x  
 
 ]]>
 </sample>
@@ -345,14 +345,14 @@ from b in [biblio]/Book ,
 <sample><![CDATA[
 <books-with-prices>
 select <book-with-price>[t1 <price-amazon>x11 <price-bn>x10 ]
-from <_>[(x3::Book|_)*] in [biblio],
-     <_>[(x9::Price|x5::Title|_)*] in x3,
+from <_ ..>[(x3::Book|_)*] in [biblio],
+     <_ ..>[(x9::Price|x5::Title|_)*] in x3,
      t1 in x5,
-     <_>[(x6::Entry|_)*] in [amazon],
-     <_>[(x7::Title|x8::Price|_)*] in x6,
+     <_ ..>[(x6::Entry|_)*] in [amazon],
+     <_ ..>[(x7::Title|x8::Price|_)*] in x6,
      t2 in x7,
-     <_>[(x10::_)*] in x9,
-     <_>[(x11::_)*] in x8
+     <_ ..>[(x10::_)*] in x9,
+     <_ ..>[(x11::_)*] in x8
  where t1=t2
 ]]>
 </sample>
@@ -377,6 +377,8 @@ where t1=t2
 
 <section title="More complex Queries: on the power of patterns">
 <sample><![CDATA[
+let bib = [biblio]/Book;;
+
 <bib>
     select <book (a)> x
       from <book (a)>[ (x::(Any\Editor)|_ )* ] in bib 
@@ -389,21 +391,21 @@ If one wants to write more explicitly:
 </p>
 <sample><![CDATA[
     select <book (a)> x
-      from <book (a)>[ (x::(Any\<editor>_)|_ )* ] in bib
+      from <book (a)>[ (x::(Any\$$<editor ..>_$$)|_ )* ] in bib
 ]]>
 </sample>
 <p>Or even:
 </p>
 <sample><![CDATA[
     select <book (a)> x
-      from <book (a)>[ (x::(<(_\`editor) ..>_)|_ )* ] in bib
+      from <book (a)>[ (x::(<($$_$$\$$`editor$$) ..>_)|_ )* ] in bib
 ]]>
 </sample>
 <p>Back to the first one:</p>
 <sample><![CDATA[
 <bib>
     select <book (a)> x
-      from <(book) (a)>[ (x::(Any\Editor)|_ )* ] in bib
+      from <$$($$book$$)$$ (a)>[ (x::(Any\Editor)|_ )* ] in bib
 ]]>
 </sample>
 <p>
@@ -412,14 +414,14 @@ removes sub-elements  editor, but you will get a warning as capture variable <co
 the from 
 </p>
 <sample><![CDATA[
-    select <(book) (a)> x
+    select <$$($$book$$)$$ (a)> x
       from <(book) (a)>[ (x::(Any\Editor)|_ )* ] in bib
 ]]>
 </sample>
-<p> Same thing but without tranforming tag to  "book".
+<p> Same thing but without tranforming tag to  "book".<br/>
 More interestingly:</p>
 <sample><![CDATA[
-    select <(b) (a\id)> x
+    select <(b) (a\$$id$$)> x
       from <(b) (a)>[ (x::(Any\Editor)|_ )* ] in bib
 ]]>
 </sample>
@@ -437,7 +439,7 @@ if such is not the case the expression is ill-typed. If one wants to perform thi
 </p>
 <sample><![CDATA[
     select <(b) (a\id+{bing=a.id})> x
-      from <(b) (a&{id=_ ..}))>[ (x::(Any\Editor)|_ )* ] in bib
+      from <(b) (a&{id=_})>[ (x::(Any\Editor)|_ )* ] in bib
 ]]>
 </sample>
 </section>