feat: getFieldData() returns nullable data on PostgreSQL

Author: kenjis

system/Database/Postgre/Connection.php

@@ -234,9 +234,9 @@ protected function _listColumns(string $table = ''): string
      */
     protected function _fieldData(string $table): array
     {
-        $sql = 'SELECT "column_name", "data_type", "character_maximum_length", "numeric_precision", "column_default"
-			FROM "information_schema"."columns"
-			WHERE LOWER("table_name") = '
+        $sql = 'SELECT "column_name", "data_type", "character_maximum_length", "numeric_precision", "column_default",  "is_nullable"
+            FROM "information_schema"."columns"
+            WHERE LOWER("table_name") = '
                 . $this->escape(strtolower($table))
                 . ' ORDER BY "ordinal_position"';
 
@@ -252,6 +252,7 @@ protected function _fieldData(string $table): array
 
             $retVal[$i]->name       = $query[$i]->column_name;
             $retVal[$i]->type       = $query[$i]->data_type;
+            $retVal[$i]->nullable   = $query[$i]->is_nullable === 'YES';
             $retVal[$i]->default    = $query[$i]->column_default;
             $retVal[$i]->max_length = $query[$i]->character_maximum_length > 0 ? $query[$i]->character_maximum_length : $query[$i]->numeric_precision;
         }

tests/system/Database/Live/ForgeTest.php

@@ -843,6 +843,9 @@ public function testAddFields()
             $this->assertSame('integer', $fieldsData[0]->type);
             $this->assertSame('character varying', $fieldsData[1]->type);
 
+            $this->assertFalse($fieldsData[0]->nullable);
+            $this->assertFalse($fieldsData[1]->nullable);
+
             $this->assertSame(32, (int) $fieldsData[0]->max_length);
             $this->assertSame(255, (int) $fieldsData[1]->max_length);