Implement CaseExpressionBuilder class

CHANGELOG.md

@@ -45,6 +45,7 @@
 - New #408, #410: Implement `DMLQueryBuilder::upsertReturning()` method (@Tigrov)
 - Enh #412: Reduce binding parameters (@Tigrov)
 - Chg #414: Rename `DMLQueryBuilder::insertWithReturningPks()` to `DMLQueryBuilder::insertReturningPks()` (@Tigrov)
+- Enh #415: Implement `CaseExpressionBuilder` class (@Tigrov)
 
 ## 1.3.0 March 21, 2024
 

src/Builder/CaseExpressionBuilder.php

@@ -0,0 +1,65 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Yiisoft\Db\Pgsql\Builder;
+
+use InvalidArgumentException;
+use Yiisoft\Db\Expression\CaseExpression;
+use Yiisoft\Db\Expression\ExpressionInterface;
+use Yiisoft\Db\Schema\Column\ColumnInterface;
+
+use function is_string;
+
+/**
+ * Builds expressions for {@see CaseExpression}.
+ */
+final class CaseExpressionBuilder extends \Yiisoft\Db\Expression\CaseExpressionBuilder
+{
+    public function build(ExpressionInterface $expression, array &$params = []): string
+    {
+        $whenClauses = $expression->getWhen();
+
+        if (empty($whenClauses)) {
+            throw new InvalidArgumentException('The CASE expression must have at least one WHEN clause.');
+        }
+
+        $sql = 'CASE';
+
+        $case = $expression->getCase();
+
+        if ($case !== null) {
+            $caseTypeHint = $this->buildTypeHint($expression->getCaseType());
+            $sql .= ' ' . $this->buildConditionWithTypeHint($case, $caseTypeHint, $params);
+        } else {
+            $caseTypeHint = '';
+        }
+
+        foreach ($whenClauses as $when) {
+            $sql .= ' WHEN ' . $this->buildConditionWithTypeHint($when->condition, $caseTypeHint, $params);
+            $sql .= ' THEN ' . $this->buildResult($when->result, $params);
+        }
+
+        if ($expression->hasElse()) {
+            $sql .= ' ELSE ' . $this->buildResult($expression->getElse(), $params);
+        }
+
+        return $sql . ' END';
+    }
+
+    private function buildConditionWithTypeHint(mixed $condition, string $typeHint, array &$params): string
+    {
+        $builtCondition = $this->buildCondition($condition, $params);
+
+        return $typeHint !== '' ? "($builtCondition)$typeHint" : $builtCondition;
+    }
+
+    private function buildTypeHint(string|ColumnInterface $type): string
+    {
+        if (is_string($type)) {
+            return $type === '' ? '' : "::$type";
+        }
+
+        return '::' . $this->queryBuilder->getColumnDefinitionBuilder()->buildType($type);
+    }
+}

src/DQLQueryBuilder.php

@@ -5,10 +5,12 @@
 namespace Yiisoft\Db\Pgsql;
 
 use Yiisoft\Db\Expression\ArrayExpression;
+use Yiisoft\Db\Expression\CaseExpression;
 use Yiisoft\Db\Expression\JsonExpression;
 use Yiisoft\Db\Expression\StructuredExpression;
 use Yiisoft\Db\Pgsql\Builder\ArrayExpressionBuilder;
 use Yiisoft\Db\Pgsql\Builder\ArrayOverlapsConditionBuilder;
+use Yiisoft\Db\Pgsql\Builder\CaseExpressionBuilder;
 use Yiisoft\Db\Pgsql\Builder\JsonOverlapsConditionBuilder;
 use Yiisoft\Db\Pgsql\Builder\LikeConditionBuilder;
 use Yiisoft\Db\Pgsql\Builder\StructuredExpressionBuilder;
@@ -51,6 +53,7 @@ protected function defaultExpressionBuilders(): array
             JsonOverlapsCondition::class => JsonOverlapsConditionBuilder::class,
             StructuredExpression::class => StructuredExpressionBuilder::class,
             LikeCondition::class => LikeConditionBuilder::class,
+            CaseExpression::class => CaseExpressionBuilder::class,
         ];
     }
 }

tests/Provider/QueryBuilderProvider.php

@@ -8,8 +8,10 @@
 use Yiisoft\Db\Constant\DataType;
 use Yiisoft\Db\Constant\PseudoType;
 use Yiisoft\Db\Expression\ArrayExpression;
+use Yiisoft\Db\Expression\CaseExpression;
 use Yiisoft\Db\Expression\Expression;
 use Yiisoft\Db\Pgsql\Column\ColumnBuilder;
+use Yiisoft\Db\Pgsql\Column\IntegerColumn;
 use Yiisoft\Db\Pgsql\Tests\Support\TestTrait;
 use Yiisoft\Db\Query\Query;
 
@@ -511,4 +513,60 @@ public static function prepareValue(): array
 
         return $values;
     }
+
+    public static function caseExpressionBuilder(): array
+    {
+        $data = parent::caseExpressionBuilder();
+
+        $db = self::getDb();
+        $serverVersion = $db->getServerInfo()->getVersion();
+        $db->close();
+
+        if (version_compare($serverVersion, '10', '<')) {
+            $data['without case expression'] = [
+                (new CaseExpression())
+                    ->addWhen(['=', 'column_name', 1], $paramA = new Param('a', DataType::STRING))
+                    ->addWhen(
+                        '"column_name" = 2',
+                        $db->select(new Expression(
+                            ':pv2::text',
+                            [':pv2' => $paramB = new Param('b', DataType::STRING)],
+                        )),
+                    ),
+                'CASE WHEN "column_name" = :qp0 THEN :qp1 WHEN "column_name" = 2 THEN (SELECT :pv2::text) END',
+                [':qp0' => 1, ':qp1' => $paramA, ':pv2' => $paramB],
+                'b',
+            ];
+        }
+
+        return [
+            ...$data,
+            'without case and type hint' => [
+                (new CaseExpression())->caseType('int')
+                    ->addWhen(true, "'a'"),
+                "CASE WHEN TRUE THEN 'a' END",
+                [],
+                'a',
+            ],
+            'with case and type hint' => [
+                (new CaseExpression('1 + 1', 'int'))
+                    ->addWhen(1, "'a'")
+                    ->else("'b'"),
+                "CASE (1 + 1)::int WHEN (1)::int THEN 'a' ELSE 'b' END",
+                [],
+                'b',
+            ],
+            'with case and type hint with column' => [
+                (new CaseExpression('1 + 1', new IntegerColumn()))
+                    ->addWhen(1, $paramA = new Param('a', DataType::STRING))
+                    ->else($paramB = new Param('b', DataType::STRING)),
+                'CASE (1 + 1)::integer WHEN (1)::integer THEN :qp0 ELSE :qp1 END',
+                [
+                    ':qp0' => $paramA,
+                    ':qp1' => $paramB,
+                ],
+                'b',
+            ],
+        ];
+    }
 }

tests/QueryBuilderTest.php

@@ -8,6 +8,7 @@
 use Yiisoft\Db\Driver\Pdo\PdoConnectionInterface;
 use Yiisoft\Db\Exception\IntegrityException;
 use Yiisoft\Db\Exception\NotSupportedException;
+use Yiisoft\Db\Expression\CaseExpression;
 use Yiisoft\Db\Expression\Expression;
 use Yiisoft\Db\Expression\ExpressionInterface;
 use Yiisoft\Db\Pgsql\Tests\Provider\QueryBuilderProvider;
@@ -576,4 +577,14 @@ public function testPrepareValue(string $expected, mixed $value): void
     {
         parent::testPrepareValue($expected, $value);
     }
+
+    #[DataProviderExternal(QueryBuilderProvider::class, 'caseExpressionBuilder')]
+    public function testCaseExpressionBuilder(
+        CaseExpression $case,
+        string $expectedSql,
+        array $expectedParams,
+        string|int $expectedResult,
+    ): void {
+        parent::testCaseExpressionBuilder($case, $expectedSql, $expectedParams, $expectedResult);
+    }
 }

tests/Support/TestTrait.php

@@ -60,7 +60,7 @@ protected function getDsn(): string
         return $this->dsn;
     }
 
-    protected function getDriverName(): string
+    protected static function getDriverName(): string
     {
         return 'pgsql';
     }