Refactor constraints (#327)

Author: Tigrov

CHANGELOG.md

@@ -49,6 +49,7 @@
 - Enh #324: Refactor `Command::insertWithReturningPks()` method (@Tigrov)
 - Enh #325: Refactor `DMLQueryBuilder::upsert()` method (@Tigrov)
 - Chg #326: Add alias in `DQLQueryBuilder::selectExists()` method for consistency with other DBMS (@Tigrov)
+- Enh #327: Refactor constraints (@Tigrov)
 - Chg #330: Rename `insertWithReturningPks()` to `insertReturningPks()` in `Command` and `DMLQueryBuilder` classes (@Tigrov)
 
 ## 1.3.0 March 21, 2024

src/DMLQueryBuilder.php

@@ -80,9 +80,9 @@ public function upsert(
         $quotedTableName = $this->quoter->quoteTableName($table);
 
         foreach ($constraints as $constraint) {
-            $columnNames = (array) $constraint->getColumnNames();
+            $columnNames = $constraint->getColumnNames();
             $constraintCondition = ['and'];
-            /** @psalm-var string[] $columnNames */
+
             foreach ($columnNames as $name) {
                 $quotedName = $this->quoter->quoteColumnName($name);
                 $constraintCondition[] = "$quotedTableName.$quotedName=\"EXCLUDED\".$quotedName";