From e42c7848c4dba805d4bfbadf95fef51527b93ab7 Mon Sep 17 00:00:00 2001
From: Ambrose Casanova <279373485+ambrose5773@users.noreply.github.com>
Date: Fri, 4 Sep 2026 02:55:48 +0000
Subject: [PATCH 1/3] fix: return false from fetchField on empty result

SimplePdo::fetchRow() returns null when there are no rows. Guard
PdoWrapper::fetchField() so empty queries return false instead of
calling getData() on null. Closes #726.
---
 flight/database/PdoWrapper.php | 5 ++++-
 tests/PdoWrapperTest.php       | 6 ++++++
 tests/SimplePdoTest.php        | 6 ++++++
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/flight/database/PdoWrapper.php b/flight/database/PdoWrapper.php
index 6f37b25b..4c036cdd 100644
--- a/flight/database/PdoWrapper.php
+++ b/flight/database/PdoWrapper.php
@@ -91,11 +91,14 @@ public function runQuery(string $sql, array $params = []): PDOStatement
      * @param string $sql   - Ex: "SELECT id FROM table WHERE something = ?"
      * @param array<int|string,mixed> $params - Ex: [ $something ]
      *
-     * @return mixed
+     * @return mixed|false
      */
     public function fetchField(string $sql, array $params = [])
     {
         $result = $this->fetchRow($sql, $params);
+        if ($result === null || count($result) === 0) {
+            return false;
+        }
         $data = $result->getData();
         return reset($data);
     }
diff --git a/tests/PdoWrapperTest.php b/tests/PdoWrapperTest.php
index d7e9311b..904d95c9 100644
--- a/tests/PdoWrapperTest.php
+++ b/tests/PdoWrapperTest.php
@@ -71,6 +71,12 @@ public function testFetchField(): void
         $this->assertEquals(2, $id);
     }
 
+    public function testFetchFieldReturnsFalseWhenNoResults(): void
+    {
+        $id = $this->pdo_wrapper->fetchField('SELECT id FROM test WHERE id = ?', [999]);
+        $this->assertFalse($id);
+    }
+
     public function testFetchRow(): void
     {
         $row = $this->pdo_wrapper->fetchRow('SELECT * FROM test WHERE name = ?', ['two']);
diff --git a/tests/SimplePdoTest.php b/tests/SimplePdoTest.php
index 08f8e164..ee416976 100644
--- a/tests/SimplePdoTest.php
+++ b/tests/SimplePdoTest.php
@@ -468,4 +468,10 @@ public function testFetchFieldReturnsFirstColumn(): void
         $id = $this->db->fetchField('SELECT id, name FROM users WHERE id = ?', [1]);
         $this->assertEquals(1, $id);
     }
+
+    public function testFetchFieldReturnsFalseWhenNoResults(): void
+    {
+        $value = $this->db->fetchField('SELECT name FROM users WHERE id = ?', [999]);
+        $this->assertFalse($value);
+    }
 }

From 386bdc16a73f6e4e0134b9dffa0ba18dc59dd6a9 Mon Sep 17 00:00:00 2001
From: Ambrose Casanova <279373485+ambrose5773@users.noreply.github.com>
Date: Fri, 4 Sep 2026 03:35:12 +0000
Subject: [PATCH 2/3] test: cover fetchField null vs empty vs 0 vs ''

Distinguish empty result sets (false) from SQL NULL columns (null),
and keep 0 / '' as assertSame on both PdoWrapper and SimplePdo.
---
 tests/PdoWrapperTest.php | 24 ++++++++++++++++++++++--
 tests/SimplePdoTest.php  | 26 +++++++++++++++++++++++---
 2 files changed, 45 insertions(+), 5 deletions(-)

diff --git a/tests/PdoWrapperTest.php b/tests/PdoWrapperTest.php
index 904d95c9..d3a29287 100644
--- a/tests/PdoWrapperTest.php
+++ b/tests/PdoWrapperTest.php
@@ -68,13 +68,33 @@ public function testRunQueryDeleteStatement(): void
     public function testFetchField(): void
     {
         $id = $this->pdo_wrapper->fetchField('SELECT id FROM test WHERE name = ?', ['two']);
-        $this->assertEquals(2, $id);
+        $this->assertSame(2, $id);
     }
 
     public function testFetchFieldReturnsFalseWhenNoResults(): void
     {
         $id = $this->pdo_wrapper->fetchField('SELECT id FROM test WHERE id = ?', [999]);
-        $this->assertFalse($id);
+        $this->assertSame(false, $id);
+    }
+
+    public function testFetchFieldReturnsNullWhenColumnIsSqlNull(): void
+    {
+        $this->pdo_wrapper->exec('INSERT INTO test (name) VALUES (NULL)');
+        $value = $this->pdo_wrapper->fetchField('SELECT name FROM test WHERE name IS NULL');
+        $this->assertNull($value);
+    }
+
+    public function testFetchFieldReturnsZero(): void
+    {
+        $value = $this->pdo_wrapper->fetchField('SELECT 0');
+        $this->assertSame(0, $value);
+    }
+
+    public function testFetchFieldReturnsEmptyString(): void
+    {
+        $this->pdo_wrapper->exec('INSERT INTO test (name) VALUES ("")');
+        $value = $this->pdo_wrapper->fetchField('SELECT name FROM test WHERE name = ?', ['']);
+        $this->assertSame('', $value);
     }
 
     public function testFetchRow(): void
diff --git a/tests/SimplePdoTest.php b/tests/SimplePdoTest.php
index ee416976..c4441af3 100644
--- a/tests/SimplePdoTest.php
+++ b/tests/SimplePdoTest.php
@@ -460,18 +460,38 @@ public function testTransactionRethrowsException(): void
     public function testFetchFieldReturnsValue(): void
     {
         $name = $this->db->fetchField('SELECT name FROM users WHERE id = ?', [1]);
-        $this->assertEquals('John', $name);
+        $this->assertSame('John', $name);
     }
 
     public function testFetchFieldReturnsFirstColumn(): void
     {
         $id = $this->db->fetchField('SELECT id, name FROM users WHERE id = ?', [1]);
-        $this->assertEquals(1, $id);
+        $this->assertSame(1, $id);
     }
 
     public function testFetchFieldReturnsFalseWhenNoResults(): void
     {
         $value = $this->db->fetchField('SELECT name FROM users WHERE id = ?', [999]);
-        $this->assertFalse($value);
+        $this->assertSame(false, $value);
+    }
+
+    public function testFetchFieldReturnsNullWhenColumnIsSqlNull(): void
+    {
+        $this->db->exec('INSERT INTO users (name, email) VALUES (NULL, "null@example.com")');
+        $value = $this->db->fetchField('SELECT name FROM users WHERE email = ?', ['null@example.com']);
+        $this->assertNull($value);
+    }
+
+    public function testFetchFieldReturnsZero(): void
+    {
+        $value = $this->db->fetchField('SELECT 0');
+        $this->assertSame(0, $value);
+    }
+
+    public function testFetchFieldReturnsEmptyString(): void
+    {
+        $this->db->exec('INSERT INTO users (name, email) VALUES ("", "empty@example.com")');
+        $value = $this->db->fetchField('SELECT name FROM users WHERE email = ?', ['empty@example.com']);
+        $this->assertSame('', $value);
     }
 }

From 9681cd20c88dcf527545b2d5bb4f76bcb554b7f8 Mon Sep 17 00:00:00 2001
From: Ambrose Casanova <279373485+ambrose5773@users.noreply.github.com>
Date: Fri, 4 Sep 2026 03:46:22 +0000
Subject: [PATCH 3/3] test: tolerate PDO numeric strings on PHP < 8.1

assertEquals for integer-ish fetchField values; keep assertSame for
false / empty string and assertNull for SQL NULL.
---
 tests/PdoWrapperTest.php | 6 ++++--
 tests/SimplePdoTest.php  | 6 ++++--
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/tests/PdoWrapperTest.php b/tests/PdoWrapperTest.php
index d3a29287..132156be 100644
--- a/tests/PdoWrapperTest.php
+++ b/tests/PdoWrapperTest.php
@@ -68,7 +68,8 @@ public function testRunQueryDeleteStatement(): void
     public function testFetchField(): void
     {
         $id = $this->pdo_wrapper->fetchField('SELECT id FROM test WHERE name = ?', ['two']);
-        $this->assertSame(2, $id);
+        // PDO SQLite may return numeric strings on PHP < 8.1
+        $this->assertEquals(2, $id);
     }
 
     public function testFetchFieldReturnsFalseWhenNoResults(): void
@@ -87,7 +88,8 @@ public function testFetchFieldReturnsNullWhenColumnIsSqlNull(): void
     public function testFetchFieldReturnsZero(): void
     {
         $value = $this->pdo_wrapper->fetchField('SELECT 0');
-        $this->assertSame(0, $value);
+        // PDO SQLite may return '0' on PHP < 8.1
+        $this->assertEquals(0, $value);
     }
 
     public function testFetchFieldReturnsEmptyString(): void
diff --git a/tests/SimplePdoTest.php b/tests/SimplePdoTest.php
index c4441af3..0143381d 100644
--- a/tests/SimplePdoTest.php
+++ b/tests/SimplePdoTest.php
@@ -466,7 +466,8 @@ public function testFetchFieldReturnsValue(): void
     public function testFetchFieldReturnsFirstColumn(): void
     {
         $id = $this->db->fetchField('SELECT id, name FROM users WHERE id = ?', [1]);
-        $this->assertSame(1, $id);
+        // PDO SQLite may return numeric strings on PHP < 8.1
+        $this->assertEquals(1, $id);
     }
 
     public function testFetchFieldReturnsFalseWhenNoResults(): void
@@ -485,7 +486,8 @@ public function testFetchFieldReturnsNullWhenColumnIsSqlNull(): void
     public function testFetchFieldReturnsZero(): void
     {
         $value = $this->db->fetchField('SELECT 0');
-        $this->assertSame(0, $value);
+        // PDO SQLite may return '0' on PHP < 8.1
+        $this->assertEquals(0, $value);
     }
 
     public function testFetchFieldReturnsEmptyString(): void