refactor(database): address whereExists review feedbacks

Signed-off-by: memleakd <121398829+memleakd@users.noreply.github.com>

Author: memleakd

system/Database/BaseBuilder.php

@@ -778,7 +778,7 @@ public function orWhereColumn(string $first, string $second, ?bool $escape = nul
      */
     public function whereExists($subquery): static
     {
-        return $this->_whereExists($subquery);
+        return $this->whereExistsSubquery($subquery);
     }
 
     /**
@@ -790,7 +790,7 @@ public function whereExists($subquery): static
      */
     public function orWhereExists($subquery): static
     {
-        return $this->_whereExists($subquery, false, 'OR ');
+        return $this->whereExistsSubquery($subquery, false, 'OR ');
     }
 
     /**
@@ -802,7 +802,7 @@ public function orWhereExists($subquery): static
      */
     public function whereNotExists($subquery): static
     {
-        return $this->_whereExists($subquery, true);
+        return $this->whereExistsSubquery($subquery, true);
     }
 
     /**
@@ -814,7 +814,7 @@ public function whereNotExists($subquery): static
      */
     public function orWhereNotExists($subquery): static
     {
-        return $this->_whereExists($subquery, true, 'OR ');
+        return $this->whereExistsSubquery($subquery, true, 'OR ');
     }
 
     /**
@@ -888,7 +888,7 @@ private function parseWhereColumnFirst(string $first): array
      *
      * @throws InvalidArgumentException
      */
-    protected function _whereExists($subquery, bool $not = false, string $type = 'AND '): static
+    protected function whereExistsSubquery($subquery, bool $not = false, string $type = 'AND '): static
     {
         if (! $this->isSubquery($subquery)) {
             throw new InvalidArgumentException(sprintf('%s() expects $subquery to be of type BaseBuilder or closure', debug_backtrace(0, 2)[1]['function']));

user_guide_src/source/database/query_builder.rst

@@ -409,7 +409,7 @@ a ``BaseBuilder`` instance:
 
 .. warning:: Raw SQL strings are not accepted. If you need to write the
     ``EXISTS`` clause yourself, use ``where()`` with a manually escaped
-    condition.
+    condition. See :ref:`query-builder-where-rawsql`.
 
 $builder->orWhereExists()
 -------------------------