[Bexley][WW] Only skip parent addresses if they are marked as 'shell' properties

bin/bexley/make-bexley-ww-postcode-db

@@ -77,7 +77,9 @@ CREATE VIRTUAL TABLE postcodes USING fts4 (
     sao_start_suffix TEXT,
     sao_end_number   TEXT,
     sao_end_suffix   TEXT,
-    sao_text         TEXT
+    sao_text         TEXT,
+
+    blpu_class       TEXT
 )
 SQL
 
@@ -123,11 +125,14 @@ my $query_postcodes = $db->prepare(
         sao_start_suffix,
         sao_end_number,
         sao_end_suffix,
-        sao_text
+        sao_text,
+
+        blpu_class
     )
     VALUES (?,?,?,
             ?,?,?,?,?,
-            ?,?,?,?,?)
+            ?,?,?,?,?,
+            ?)
 SQL
 );
 
@@ -195,6 +200,8 @@ my @columns_lpi = (
 
 say 'Populating tables...';
 
+my %uprn_to_blpu_class;
+
 # Cannot set column names / headers in usual way as CSV contains multiple
 # record types
 while( my $row = $csv->getline($fh) ) {
@@ -214,6 +221,8 @@ while( my $row = $csv->getline($fh) ) {
     } elsif ( $record_id == $id_blpu ) {
         @row_h{@columns_blpu} = @$row;
 
+        $uprn_to_blpu_class{ $row_h{UPRN} } = $row_h{BLPU_CLASS};
+
         next if ( $row_h{LOGICAL_STATUS} || 0 ) != 1;
         next unless $row_h{PARENT_UPRN};
 
@@ -230,6 +239,8 @@ while( my $row = $csv->getline($fh) ) {
         # Remove whitespace from postcode
         my $postcode = $row_h{POSTCODE} =~ s/ //gr;
 
+        my $blpu_class = $uprn_to_blpu_class{ $row_h{UPRN} } // '';
+
         $query_postcodes->execute(
             $postcode,
             $row_h{UPRN},
@@ -246,20 +257,10 @@ while( my $row = $csv->getline($fh) ) {
             $row_h{SAO_END_NUMBER},
             $row_h{SAO_END_SUFFIX},
             $row_h{SAO_TEXT},
+
+            $blpu_class,
         );
     }
 }
 
-# It is possible for UPRNs in child_uprns to not occur in the postcodes table
-# (an 'empty' address).
-# At least one address, UPRN 100020276242, was not being picked up
-# by Bexley WW's address lookup, because it appeared as a parent_uprn in this
-# table, but its 'child' addresses were empty.
-$db->do(<<SQL);
-DELETE FROM child_uprns
-      WHERE uprn NOT IN (
-        SELECT uprn FROM postcodes
-      )
-SQL
-
 say 'Tables populated';

perllib/BexleyAddresses.pm

@@ -14,15 +14,21 @@ That script shows the setup of the database in more detail, but to explain brief
 
 =item * postcodes
 
-Stores postcode, UPRN, USRN, and address portions (e.g. house number and name) for each property (properties are uniquely identified by their UPRN)
+Stores postcode, UPRN, USRN, and address portions (e.g. house number and name) for each property (properties are uniquely identified by their UPRN).
+
+Also stores 'blpu_class'; if it is 'P' or 'PP', it means the property is a
+'parent shell' and so should not be offered as a selectable address.
 
 =item * street_descriptors
 
 Stores address data (e.g. street & town name) for each USRN (street identifier)
 
 =item * child_uprns
 
-Captures mapping between parent and child properties (e.g. if a building contains multiple flats, the building is the parent, the children are the flats)
+Captures mapping between parent and child properties (e.g. if a building contains multiple flats, the building is the parent, the children are the flats).
+
+If a property has a parent, the parent's address details ('Secondary
+Addressable Object' or sao_* fields) are included in the address.
 
 =back
 
@@ -72,6 +78,8 @@ sub addresses_for_postcode {
 
     my $address_fields = _address_fields();
 
+    # If blpu_class is 'P' or 'PP', it means the property is a
+    # 'parent shell' and so should not be offered as an option
     my $addresses = $db->selectall_arrayref(
         <<"SQL",
    SELECT p.uprn uprn,
@@ -83,9 +91,8 @@ sub addresses_for_postcode {
      LEFT OUTER JOIN child_uprns cu
        ON cu.uprn = p.uprn
     WHERE p.postcode = ?
-      AND p.uprn NOT IN (
-        SELECT parent_uprn FROM child_uprns
-      )
+      AND p.blpu_class != 'P'
+      AND p.blpu_class != 'PP'
 SQL
         { Slice => {} },
         $postcode,