SqlPreprocessor: backtick identifiers are skipped when looking for placeholders [Closes #318]

Author: dg

src/Database/SqlPreprocessor.php

@@ -99,6 +99,7 @@ public function process(array $params, bool $useParams = false): array
 						~
 							'[^']*+'
 							|"[^"]*+"
+							|`[^`]*+`
 							|\?[a-z]*
 							|^\s*+(?:\(?\s*SELECT|INSERT|UPDATE|DELETE|REPLACE|EXPLAIN)\b
 							|\b(?:SET|WHERE|HAVING|ORDER\ BY|GROUP\ BY|KEY\ UPDATE)(?=\s*$|\s*\?)
@@ -126,7 +127,7 @@ public function process(array $params, bool $useParams = false): array
 	private function parsePart(array $match): string
 	{
 		$match = $match[0];
-		if (in_array($match[0], ["'", '"', '/', '-'], true)) { // string or comment
+		if (in_array($match[0], ["'", '"', '`', '/', '-'], true)) { // string, identifier or comment
 			return $match;
 
 		} elseif (!str_contains($match, '?')) { // command

tests/Database/SqlPreprocessor.phpt

@@ -134,6 +134,17 @@ test('Preserves string literals containing question marks', function () use ($pr
 });
 
 
+test('Preserves backtick identifiers containing question marks or comment marks', function () use ($preprocessor) {
+	[$sql, $params] = $preprocessor->process(['SELECT `a?`.id FROM author AS `a?` WHERE id = ?', 11]);
+	Assert::same('SELECT `a?`.id FROM author AS `a?` WHERE id = ?', $sql);
+	Assert::same([11], $params);
+
+	[$sql, $params] = $preprocessor->process(['SELECT `a--b`.id FROM author AS `a--b` WHERE id > ? AND id < ?', 11, 12]);
+	Assert::same('SELECT `a--b`.id FROM author AS `a--b` WHERE id > ? AND id < ?', $sql);
+	Assert::same([11, 12], $params);
+});
+
+
 test('Auto-detects operator in WHERE conditions', function () use ($preprocessor) {
 	[$sql, $params] = $preprocessor->process(['SELECT id FROM tbl WHERE', [
 		'col_null' => null,