Create case insensitive indexes for case insensitive attributes (CO-2…

…211)

app/src/Lib/Match/MatchgridBuilder.php

@@ -103,6 +103,9 @@ protected function configToSchema($dbc, \Cake\Datasource\EntityInterface $Matchg
 
     $table->setPrimaryKey(["id"]);
 
+    // Track which attributes need case insensitive indexes
+    $ciAttrs = [];
+
     if($indexes) {
       // Since index names need to be unique across the schema, we'll use the
       // matchgrid ID to make the names unique.
@@ -124,7 +127,13 @@ protected function configToSchema($dbc, \Cake\Datasource\EntityInterface $Matchg
       // Add in indexes for configured fields
       foreach($attributes as $attr) {
         // We use the Entity ID to provide some level of reproducibility
-        $table->addIndex([$attr->name], 'matchgrid_' . $Matchgrid->id . '_attr_id'.$attr->id, $flags, $options);
+        $indexName = 'matchgrid_' . $Matchgrid->id . '_attr_id' . $attr->id;
+
+        $table->addIndex([$attr->name], $indexName, $flags, $options);
+
+        if(!$attr->case_sensitive) {
+          $ciAttrs[$indexName] = $attr->name;
+        }
       }
     }
 
@@ -151,10 +160,23 @@ protected function configToSchema($dbc, \Cake\Datasource\EntityInterface $Matchg
     // needs to be fixed.
 
     foreach($diffSql as $sql) {
+      $matches = false;
       if(preg_match("/^CREATE INDEX .* \(resolution_time\)$/", $sql)) {
         // We need the resolution_time index to sort NULLS FIRST, and this is
         // currently the least painful way to do it
         $sql = rtrim($sql, ")") . " NULLS FIRST)";
+      } elseif(preg_match("/^CREATE INDEX (\w+) ON .*/", $sql, $matches)) {
+        $attr = $ciAttrs[ $matches[1] ];
+
+        // Not ideal to hardcode SQL, but this should be pretty portable.
+        // Note the validation rule for table_name and attr is pretty restrictive,
+        // so we don't need to SQL escape them. Similarly, we create the index
+        // name above.
+
+        // We use IF NOT EXISTS to avoid errors on rebuilding the matchgrid,
+        // however a better long term solution would be to add native support to
+        // DBAL for expression in index creation (CO-2217).
+        $sql = "CREATE INDEX IF NOT EXISTS " . $matches[1] . " ON " . $Matchgrid->prefixed_table_name . " (LOWER(" . $attr . "))";
       }
 
       $stmt = $dbc->query($sql);