Apply suggestion from @greptile-apps[bot]

Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

Author: abnegate

src/Query/Schema/ClickHouse.php

@@ -51,13 +51,13 @@ protected function compileColumnType(Column $column): string
                 throw new UnsupportedException('LowCardinality is not supported inside Array(...). Wrap the element type instead.');
             }
 
-            $inner = $this->compileNestedElementType($column->arrayElementType, $column);
-            $type = 'Array(' . $inner . ')';
-
             if ($column->isNullable) {
-                $type = 'Nullable(' . $type . ')';
+                throw new UnsupportedException('Nullable(Array(...)) is not supported in ClickHouse. Use an empty array [] to represent a missing value instead.');
             }
 
+            $inner = $this->compileNestedElementType($column->arrayElementType, $column);
+            $type = 'Array(' . $inner . ')';
+
             return $type;
         }