fix(builder): preserve whitespace between SELECT and UNION body in CREATE VIEW (#655)

Signed-off-by: SAY-5 <say.apm35@gmail.com>

Author: SAY-5

src/Statements/CreateStatement.php

@@ -462,11 +462,22 @@ public function build(): string
                 $builtStatement = $this->with->build();
             }
 
+            $body = TokensList::buildFromArray($this->body);
+            // Body tokens (e.g. trailing `UNION ALL (SELECT ...)` after the
+            // primary SELECT) are concatenated raw, so without a separator
+            // the rebuilt SQL collides with the SELECT's last token —
+            // `WHERE 3 = 3union all` instead of `WHERE 3 = 3 union all`.
+            // Only insert a space when neither side already has one to
+            // avoid double-spacing the WITH...AS path.
+            $separator = ($builtStatement !== '' && $body !== ''
+                && substr($builtStatement, -1) !== ' '
+                && $body[0] !== ' ') ? ' ' : '';
+
             return 'CREATE '
                 . $this->options->build() . ' '
                 . $this->name->build() . ' '
                 . $fields . ' AS ' . $builtStatement
-                . TokensList::buildFromArray($this->body) . ' '
+                . $separator . $body . ' '
                 . ($this->entityOptions?->build() ?? '');
         }
 

tests/Builder/CreateStatementTest.php

@@ -897,4 +897,29 @@ public function testBuildCreateTableComplexIndexes(): void
             $stmt->build(),
         );
     }
+
+    /**
+     * Regression for #655: `CREATE VIEW ... AS SELECT ... WHERE ... UNION ALL (...)`
+     * used to lose the whitespace between the SELECT body and the trailing
+     * UNION clause, producing invalid SQL like `WHERE 3 = 3union all (...)`.
+     */
+    public function testBuilderViewWithUnionPreservesWhitespace(): void
+    {
+        $sql = "CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER "
+            . "VIEW `v1` AS select 1 AS `a` where 3 = 3 union all (select 2 AS `a`)";
+
+        $parser = new Parser($sql);
+        $built = $parser->statements[0]->build();
+
+        $this->assertStringNotContainsString(
+            '3union all',
+            $built,
+            'rebuilt CREATE VIEW must keep the space between WHERE clause and UNION',
+        );
+        $this->assertStringContainsString(
+            '3 union all',
+            // case-insensitive match: builder may upper-case the keyword
+            preg_replace('/UNION\s+ALL/i', 'union all', $built),
+        );
+    }
 }