add support for split_part function (#236)

docs/AVAILABLE-FUNCTIONS-AND-OPERATORS.md

@@ -76,6 +76,7 @@
 | regexp_replace (with flags) | FLAGGED_REGEXP_REPLACE | `MartinGeorgiev\Doctrine\ORM\Query\AST\Functions\FlaggedRegexpReplace` |
 | regexp_replace (with no flags) | REGEXP_REPLACE | `MartinGeorgiev\Doctrine\ORM\Query\AST\Functions\RegexpReplace` |
 | row_to_json | ROW_TO_JSON | `MartinGeorgiev\Doctrine\ORM\Query\AST\Functions\RowToJson` |
+| split_part | SPLIT_PART | `MartinGeorgiev\Doctrine\ORM\Query\AST\Functions\SplitPart` |
 | starts_with | STARTS_WITH | `MartinGeorgiev\Doctrine\ORM\Query\AST\Functions\StartsWith` |
 | string_agg | STRING_AGG | `MartinGeorgiev\Doctrine\ORM\Query\AST\Functions\StringAgg` |
 | string_to_array | STRING_TO_ARRAY | `MartinGeorgiev\Doctrine\ORM\Query\AST\Functions\StringToArray` |

src/MartinGeorgiev/Doctrine/ORM/Query/AST/Functions/SplitPart.php

@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MartinGeorgiev\Doctrine\ORM\Query\AST\Functions;
+
+/**
+ * Implementation of PostgreSql SPLIT_PART().
+ *
+ * @see https://www.postgresql.org/docs/15/functions-string.html
+ */
+class SplitPart extends BaseFunction
+{
+    protected function customiseFunction(): void
+    {
+        $this->setFunctionPrototype('split_part(%s, %s, %s)');
+        $this->addNodeMapping('StringPrimary');
+        $this->addNodeMapping('StringPrimary');
+        $this->addNodeMapping('SimpleArithmeticExpression');
+    }
+}

tests/MartinGeorgiev/Doctrine/ORM/Query/AST/Functions/SplitPartTest.php

@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\MartinGeorgiev\Doctrine\ORM\Query\AST\Functions;
+
+use Fixtures\MartinGeorgiev\Doctrine\Entity\ContainsTexts;
+use MartinGeorgiev\Doctrine\ORM\Query\AST\Functions\SplitPart;
+
+class SplitPartTest extends TestCase
+{
+    protected function getStringFunctions(): array
+    {
+        return [
+            'SPLIT_PART' => SplitPart::class,
+        ];
+    }
+
+    protected function getExpectedSqlStatements(): array
+    {
+        return [
+            "SELECT split_part(c0_.text1, ',', 1) AS sclr_0 FROM ContainsTexts c0_",
+            "SELECT split_part(c0_.text2, '-', -2) AS sclr_0 FROM ContainsTexts c0_",
+        ];
+    }
+
+    protected function getDqlStatements(): array
+    {
+        return [
+            \sprintf("SELECT SPLIT_PART(e.text1, ',', 1) FROM %s e", ContainsTexts::class),
+            \sprintf("SELECT SPLIT_PART(e.text2, '-', -2) FROM %s e", ContainsTexts::class),
+        ];
+    }
+}