From 369f3ba9a50cc19d461c7f1e2ab658a5a5a57788 Mon Sep 17 00:00:00 2001
From: Yuri Kuznetsov <yurikuzn@users.noreply.github.com>
Date: Tue, 7 Mar 2023 18:52:49 +0200
Subject: [PATCH] switch complex expr

---
 .../Espo/ORM/Query/Part/Expression.php        | 15 ++++++++++
 .../ORM/QueryComposer/BaseQueryComposer.php   | 22 +++++++++++++++
 .../Espo/ORM/QueryComposer/Functions.php      |  1 +
 .../unit/Espo/ORM/MysqlQueryComposerTest.php  | 28 +++++++++++++++++++
 4 files changed, 66 insertions(+)

diff --git a/application/Espo/ORM/Query/Part/Expression.php b/application/Espo/ORM/Query/Part/Expression.php
index 3badfb7a9f..37a01596d1 100644
--- a/application/Espo/ORM/Query/Part/Expression.php
+++ b/application/Espo/ORM/Query/Part/Expression.php
@@ -186,6 +186,21 @@ class Expression implements WhereItem
         return self::composeFunction('IF', $condition, $then, $else);
     }
 
+    /**
+     * 'CASE' expression. Even arguments define 'WHEN' conditions, following odd arguments
+     * define 'THEN' values. The last unmatched argument defines 'ELSE'.
+     *
+     * @param Expression|scalar|null ...$arguments Arguments.
+     */
+    public static function switch(Expression|string|int|float|bool|null ...$arguments): self
+    {
+        if (count($arguments) < 2) {
+            throw new RuntimeException("Too few arguments.");
+        }
+
+        return self::composeFunction('SWITCH', ...$arguments);
+    }
+
     /**
      * 'IFNULL' function. If the first argument is not NULL, returns it,
      * otherwise returns the second argument.
diff --git a/application/Espo/ORM/QueryComposer/BaseQueryComposer.php b/application/Espo/ORM/QueryComposer/BaseQueryComposer.php
index 63f4d79cf9..6dc95b66e7 100644
--- a/application/Espo/ORM/QueryComposer/BaseQueryComposer.php
+++ b/application/Espo/ORM/QueryComposer/BaseQueryComposer.php
@@ -950,6 +950,28 @@ abstract class BaseQueryComposer implements QueryComposer
         }
 
         switch ($function) {
+            case 'SWITCH':
+                if (count($argumentPartList) < 2) {
+                    throw new RuntimeException("Not enough arguments for SWITCH function.");
+                }
+
+                $part = "CASE";
+
+                for ($i = 0; $i < floor(count($argumentPartList) / 2); $i++) {
+                    $whenPart = $argumentPartList[$i * 2];
+                    $thenPart = $argumentPartList[$i * 2 + 1];
+
+                    $part .= " WHEN {$whenPart} THEN {$thenPart}";
+                }
+
+                if (count($argumentPartList) % 2) {
+                    $part .= " ELSE " . end($argumentPartList);
+                }
+
+                $part .= " END";
+
+                return $part;
+
             case 'MONTH':
                 return "DATE_FORMAT({$part}, '%Y-%m')";
 
diff --git a/application/Espo/ORM/QueryComposer/Functions.php b/application/Espo/ORM/QueryComposer/Functions.php
index b479ad961c..e8ef5dd954 100644
--- a/application/Espo/ORM/QueryComposer/Functions.php
+++ b/application/Espo/ORM/QueryComposer/Functions.php
@@ -122,6 +122,7 @@ class Functions
         'NOT_IN',
         'IFNULL',
         'NULLIF',
+        'SWITCH',
         'BINARY',
         'MD5',
         'UNIX_TIMESTAMP',
diff --git a/tests/unit/Espo/ORM/MysqlQueryComposerTest.php b/tests/unit/Espo/ORM/MysqlQueryComposerTest.php
index d01502a3f0..c52c844b1c 100644
--- a/tests/unit/Espo/ORM/MysqlQueryComposerTest.php
+++ b/tests/unit/Espo/ORM/MysqlQueryComposerTest.php
@@ -2888,4 +2888,32 @@ class MysqlQueryComposerTest extends \PHPUnit\Framework\TestCase
             $this->query->composeSelect($query)
         );
     }
+
+    public function testSwitch1(): void
+    {
+        $sql = "SELECT CASE WHEN 1 THEN '1' WHEN 0 THEN '0' ELSE NULL END AS `value`";
+
+        $query = SelectBuilder::create()
+            ->select('SWITCH:(1, "1", 0, "0", null)', 'value')
+            ->build();
+
+        $this->assertEquals(
+            $sql,
+            $this->query->composeSelect($query)
+        );
+    }
+
+    public function testSwitch2(): void
+    {
+        $sql = "SELECT CASE WHEN 1 THEN '1' WHEN 0 THEN '0' END AS `value`";
+
+        $query = SelectBuilder::create()
+            ->select('SWITCH:(1, "1", 0, "0")', 'value')
+            ->build();
+
+        $this->assertEquals(
+            $sql,
+            $this->query->composeSelect($query)
+        );
+    }
 }