diff --git a/system/Database/Postgre/Builder.php b/system/Database/Postgre/Builder.php
index 4e5245bca994..5367ae2a0fc3 100644
--- a/system/Database/Postgre/Builder.php
+++ b/system/Database/Postgre/Builder.php
@@ -395,14 +395,20 @@ static function ($key, $value) use ($table, $alias, $that): RawSql|string {
         if (isset($this->QBOptions['setQueryAsData'])) {
             $data = $this->QBOptions['setQueryAsData'];
         } else {
+            $updateFields = $this->QBOptions['updateFields'] ?? [];
+
             $data = implode(
                 " UNION ALL\n",
                 array_map(
-                    static fn ($value): string => 'SELECT ' . implode(', ', array_map(
-                        static fn ($key, $index): string => $index . ' ' . $key,
+                    fn (array $value): string => sprintf('SELECT %s', implode(', ', array_map(
+                        fn (string $key, float|int|string $index): string => sprintf(
+                            '%s %s',
+                            $this->castValue((string) $index, $this->getSourceType($table, $key, $updateFields)),
+                            $key,
+                        ),
                         $keys,
                         $value,
-                    )),
+                    ))),
                     $values,
                 ),
             ) . "\n";
@@ -411,6 +417,38 @@ static function ($key, $value) use ($table, $alias, $that): RawSql|string {
         return str_replace('{:_table_:}', $data, $sql);
     }
 
+    /**
+     * Returns the type shared by every destination column fed from the source key, or null when they differ.
+     *
+     * @param array<array-key, RawSql|string> $map Destination column to source key.
+     */
+    private function getSourceType(string $table, string $key, array $map): ?string
+    {
+        $columns = array_filter(array_keys($map, $key, true), is_string(...));
+
+        if ($columns === []) {
+            return $this->getFieldType($table, $key);
+        }
+
+        $types = array_unique(array_map(fn (string $column): ?string => $this->getFieldType($table, $column), $columns));
+
+        return count($types) === 1 ? reset($types) : null;
+    }
+
+    /**
+     * Returns the literal cast to the column type, except a numeric literal for a numeric column, which stays as is so a non-integral value never rounds into a match.
+     */
+    private function castValue(string $value, ?string $type): string
+    {
+        $isNumericType = in_array(strtolower((string) $type), ['smallint', 'integer', 'bigint', 'numeric', 'real', 'double precision'], true);
+
+        if ($isNumericType && is_numeric($value)) {
+            return $value;
+        }
+
+        return $this->cast($value, $type);
+    }
+
     /**
      * Returns cast expression.
      *
@@ -437,11 +475,15 @@ private function getFieldType(string $table, string $fieldName): ?string
             foreach ($this->db->getFieldData($table) as $field) {
                 $type = $field->type;
 
-                // If `character` (or `char`) lacks a specifier, it is equivalent
-                // to `character(1)`.
-                // See https://www.postgresql.org/docs/current/datatype-character.html
-                if ($field->type === 'character') {
-                    $type = $field->type . '(' . $field->max_length . ')';
+                // information_schema reports enum, domain and array columns as `USER-DEFINED` or `ARRAY`, which are not castable names.
+                if ($type === 'USER-DEFINED' || $type === 'ARRAY') {
+                    continue;
+                }
+
+                // `character` without a length is `character(1)` and `character(n)` truncates on cast,
+                // while `bpchar` keeps the full value.
+                if ($type === 'character') {
+                    $type = 'bpchar';
                 }
 
                 $this->QBOptions['fieldTypes'][$table][$field->name] = $type;
@@ -613,14 +655,20 @@ static function ($key, $value) use ($table, $alias, $that): RawSql|string {
         if (isset($this->QBOptions['setQueryAsData'])) {
             $data = $this->QBOptions['setQueryAsData'];
         } else {
+            $constraints = $this->QBOptions['constraints'] ?? [];
+
             $data = implode(
                 " UNION ALL\n",
                 array_map(
-                    static fn ($value): string => 'SELECT ' . implode(', ', array_map(
-                        static fn ($key, $index): string => $index . ' ' . $key,
+                    fn (array $value): string => sprintf('SELECT %s', implode(', ', array_map(
+                        fn (string $key, float|int|string $index): string => sprintf(
+                            '%s %s',
+                            $this->castValue((string) $index, $this->getSourceType($table, $key, $constraints)),
+                            $key,
+                        ),
                         $keys,
                         $value,
-                    )),
+                    ))),
                     $values,
                 ),
             ) . "\n";
diff --git a/tests/system/Database/Builder/DeleteTest.php b/tests/system/Database/Builder/DeleteTest.php
index 200eb9ca5b4a..0866cac724a4 100644
--- a/tests/system/Database/Builder/DeleteTest.php
+++ b/tests/system/Database/Builder/DeleteTest.php
@@ -14,6 +14,7 @@
 namespace CodeIgniter\Database\Builder;
 
 use CodeIgniter\Database\BaseBuilder;
+use CodeIgniter\Database\Postgre\Builder as PostgreBuilder;
 use CodeIgniter\Test\CIUnitTestCase;
 use CodeIgniter\Test\Mock\MockConnection;
 use CodeIgniter\Test\Mock\MockQuery;
@@ -169,4 +170,50 @@ public function testDeleteBatchEscapesWhereInBinds(): void
         $this->assertStringContainsString("IN ('anything'' OR ''1''=''1','Ahmadinejad')", $query->getQuery());
         $this->assertStringNotContainsString("IN anything' OR '1'='1", $query->getQuery());
     }
+
+    public function testDeleteBatchPostgreCastsPositionalAndMappedConstraints(): void
+    {
+        $db = new class (['DBDriver' => 'Postgre']) extends MockConnection {
+            protected function _fieldData(string $table): array
+            {
+                return [
+                    (object) ['name' => 'id', 'type' => 'integer', 'max_length' => 32],
+                    (object) ['name' => 'name', 'type' => 'text', 'max_length' => null],
+                ];
+            }
+        };
+
+        $positional = (new PostgreBuilder('jobs', $db))->testMode()
+            ->setData([['id' => 1], ['id' => '2'], ['id' => 1.4]], null, 'data')
+            ->onConstraint('id')
+            ->deleteBatch();
+
+        $expected = <<<'EOF'
+            DELETE FROM "jobs"
+            USING (
+            SELECT 1 "id" UNION ALL
+            SELECT CAST('2' AS INTEGER) "id" UNION ALL
+            SELECT 1.4 "id"
+            ) "data"
+            WHERE "jobs"."id" = "data"."id"
+            EOF;
+
+        $this->assertSame($expected, rtrim($positional[0]));
+
+        $mapped = (new PostgreBuilder('jobs', $db))->testMode()
+            ->setData([['value' => 'x'], ['value' => 5]], null, 'data')
+            ->onConstraint(['name' => 'value'])
+            ->deleteBatch();
+
+        $expected = <<<'EOF'
+            DELETE FROM "jobs"
+            USING (
+            SELECT CAST('x' AS TEXT) "value" UNION ALL
+            SELECT CAST(5 AS TEXT) "value"
+            ) "data"
+            WHERE "jobs"."name" = CAST("data"."value" AS TEXT)
+            EOF;
+
+        $this->assertSame($expected, rtrim($mapped[0]));
+    }
 }
diff --git a/tests/system/Database/Builder/UpdateTest.php b/tests/system/Database/Builder/UpdateTest.php
index 5a4ccd0be9d3..91b220b0ba1b 100644
--- a/tests/system/Database/Builder/UpdateTest.php
+++ b/tests/system/Database/Builder/UpdateTest.php
@@ -15,6 +15,7 @@
 
 use CodeIgniter\Database\BaseBuilder;
 use CodeIgniter\Database\Exceptions\DatabaseException;
+use CodeIgniter\Database\Postgre\Builder as PostgreBuilder;
 use CodeIgniter\Test\CIUnitTestCase;
 use CodeIgniter\Test\Mock\MockConnection;
 use CodeIgniter\Test\Mock\MockQuery;
@@ -469,4 +470,72 @@ public function testSetWithAndWithoutEscape(): void
         $this->assertSame($expectedSQL, str_replace("\n", ' ', $builder->getCompiledUpdate()));
         $this->assertSame($expectedBinds, $builder->getBinds());
     }
+
+    public function testUpdateBatchPostgreDoesNotCastEnumAndArrayColumns(): void
+    {
+        $db = new class (['DBDriver' => 'Postgre']) extends MockConnection {
+            protected function _fieldData(string $table): array
+            {
+                return [
+                    (object) ['name' => 'id', 'type' => 'integer', 'max_length' => 32],
+                    (object) ['name' => 'mood', 'type' => 'USER-DEFINED', 'max_length' => null],
+                    (object) ['name' => 'tags', 'type' => 'ARRAY', 'max_length' => null],
+                ];
+            }
+        };
+
+        $builder = new PostgreBuilder('jobs', $db);
+        $sql     = $builder->testMode()->updateBatch([
+            ['id' => 1, 'mood' => 'happy', 'tags' => '{a}'],
+            ['id' => 2, 'mood' => 'sad', 'tags' => '{b}'],
+        ], 'id');
+
+        $expected = <<<'EOF'
+            UPDATE "jobs"
+            SET
+            "mood" = _u."mood",
+            "tags" = _u."tags"
+            FROM (
+            SELECT 1 "id", 'happy' "mood", '{a}' "tags" UNION ALL
+            SELECT 2 "id", 'sad' "mood", '{b}' "tags"
+            ) _u
+            WHERE "jobs"."id" = CAST(_u."id" AS INTEGER)
+            EOF;
+
+        $this->assertSame([$expected], $sql);
+    }
+
+    public function testUpdateBatchPostgreDoesNotCastSourceSharedByColumnsOfDifferentTypes(): void
+    {
+        $db = new class (['DBDriver' => 'Postgre']) extends MockConnection {
+            protected function _fieldData(string $table): array
+            {
+                return [
+                    (object) ['name' => 'id', 'type' => 'integer', 'max_length' => 32],
+                    (object) ['name' => 'number', 'type' => 'integer', 'max_length' => 32],
+                    (object) ['name' => 'label', 'type' => 'text', 'max_length' => null],
+                ];
+            }
+        };
+
+        $builder = new PostgreBuilder('jobs', $db);
+        $sql     = $builder->testMode()
+            ->setData([['id' => 1, 'value' => 1.4]], null, 'data')
+            ->updateFields(['number' => 'value', 'label' => 'value'])
+            ->onConstraint('id')
+            ->updateBatch();
+
+        $expected = <<<'EOF'
+            UPDATE "jobs"
+            SET
+            "number" = CAST("data"."value" AS INTEGER),
+            "label" = CAST("data"."value" AS TEXT)
+            FROM (
+            SELECT 1 "id", 1.4 "value"
+            ) "data"
+            WHERE "jobs"."id" = CAST("data"."id" AS INTEGER)
+            EOF;
+
+        $this->assertSame([$expected], $sql);
+    }
 }
diff --git a/tests/system/Database/Live/DeleteTest.php b/tests/system/Database/Live/DeleteTest.php
index 651dff251a7f..daef35068386 100644
--- a/tests/system/Database/Live/DeleteTest.php
+++ b/tests/system/Database/Live/DeleteTest.php
@@ -119,6 +119,81 @@ public function testDeleteBatchPreventsSQLInjectionInWhere(): void
         $this->seeInDatabase('user', ['email' => 'derek@world.com', 'name' => 'Derek Jones']);
     }
 
+    public function testDeleteBatchWithMixedConstraintValueTypesInTextColumn(): void
+    {
+        if ($this->db->DBDriver === 'SQLSRV') {
+            $this->markTestSkipped('SQL Server cannot compare `text` columns with `=`.');
+        }
+
+        if ($this->db->DBDriver === 'OCI8') {
+            $this->markTestSkipped('TODO: the OCI8 builder does not cast mixed `UNION ALL` values yet. Remove this skip once it does.');
+        }
+
+        $table = 'type_test';
+
+        $builder = $this->db->table($table);
+        $builder->truncate();
+
+        foreach (['Example', '587', 'kept'] as $i => $text) {
+            $builder->insert([
+                'type_varchar'  => 'test' . $i,
+                'type_char'     => 'char',
+                'type_text'     => $text,
+                'type_smallint' => 32767,
+                'type_integer'  => 2_147_483_647,
+                'type_bigint'   => 9_223_372_036_854_775_807,
+                'type_float'    => 10.1,
+                'type_numeric'  => 123.23,
+                'type_date'     => '2023-12-0' . ($i + 1),
+                'type_datetime' => '2023-12-21 12:00:00',
+            ]);
+        }
+
+        $this->db->table($table)
+            ->setData([['text' => 'Example'], ['text' => 587]], null, 'data')
+            ->onConstraint(['type_text' => 'text'])
+            ->deleteBatch();
+
+        $this->dontSeeInDatabase($table, ['type_varchar' => 'test0']);
+        $this->dontSeeInDatabase($table, ['type_varchar' => 'test1']);
+        $this->seeInDatabase($table, ['type_varchar' => 'test2']);
+    }
+
+    public function testDeleteBatchDoesNotTruncateConstraintValueForCharColumn(): void
+    {
+        if ($this->db->DBDriver === 'OCI8') {
+            $this->markTestSkipped('TODO: Oracle resolves a `UNION ALL` of `CHAR` literals with different lengths to `VARCHAR2`, so the OCI8 builder must cast them. Remove this skip once it does.');
+        }
+
+        $table = 'type_test';
+
+        $builder = $this->db->table($table);
+        $builder->truncate();
+
+        for ($i = 0; $i < 2; $i++) {
+            $builder->insert([
+                'type_varchar'  => 'test' . $i,
+                'type_char'     => 'char' . $i,
+                'type_text'     => 'text',
+                'type_smallint' => 32767,
+                'type_integer'  => 2_147_483_647,
+                'type_bigint'   => 9_223_372_036_854_775_807,
+                'type_float'    => 10.1,
+                'type_numeric'  => 123.23,
+                'type_date'     => '2023-12-0' . ($i + 1),
+                'type_datetime' => '2023-12-21 12:00:00',
+            ]);
+        }
+
+        $this->db->table($table)
+            ->setData([['char' => 'char0     X'], ['char' => 'char1']], null, 'data')
+            ->onConstraint(['type_char' => 'char'])
+            ->deleteBatch();
+
+        $this->seeInDatabase($table, ['type_varchar' => 'test0']);
+        $this->dontSeeInDatabase($table, ['type_varchar' => 'test1']);
+    }
+
     public function testDeleteBatchConstraintsDate(): void
     {
         $table = 'type_test';
diff --git a/tests/system/Database/Live/UpdateTest.php b/tests/system/Database/Live/UpdateTest.php
index 8961e7b05664..4e3944a6c6c2 100644
--- a/tests/system/Database/Live/UpdateTest.php
+++ b/tests/system/Database/Live/UpdateTest.php
@@ -278,6 +278,156 @@ public static function provideUpdateBatch(): iterable
         ];
     }
 
+    public function testUpdateBatchWithMixedValueTypesInTextColumn(): void
+    {
+        if ($this->db->DBDriver === 'SQLSRV') {
+            $this->markTestSkipped('SQL Server cannot compare `text` columns with `=`.');
+        }
+
+        if ($this->db->DBDriver === 'OCI8') {
+            $this->markTestSkipped('TODO: the OCI8 builder does not cast mixed `UNION ALL` values yet. Remove this skip once it does.');
+        }
+
+        $table = 'type_test';
+
+        $builder = $this->db->table($table);
+        $builder->truncate();
+
+        for ($i = 1; $i < 3; $i++) {
+            $builder->insert([
+                'type_varchar'  => 'test' . $i,
+                'type_char'     => 'char' . $i,
+                'type_text'     => 'text',
+                'type_smallint' => 32767,
+                'type_integer'  => 2_147_483_647,
+                'type_bigint'   => 9_223_372_036_854_775_807,
+                'type_float'    => 10.1,
+                'type_numeric'  => 123.23,
+                'type_date'     => '2023-12-0' . $i,
+                'type_datetime' => '2023-12-21 12:00:00',
+            ]);
+        }
+
+        $this->db->table($table)->updateBatch([
+            ['type_varchar' => 'test1', 'type_text' => 'Example'],
+            ['type_varchar' => 'test2', 'type_text' => 587],
+        ], 'type_varchar');
+
+        $this->seeInDatabase($table, ['type_varchar' => 'test1', 'type_text' => 'Example']);
+        $this->seeInDatabase($table, ['type_varchar' => 'test2', 'type_text' => '587']);
+    }
+
+    public function testUpdateBatchDoesNotTruncateConstraintValueForCharColumn(): void
+    {
+        if ($this->db->DBDriver === 'OCI8') {
+            $this->markTestSkipped('TODO: Oracle resolves a `UNION ALL` of `CHAR` literals with different lengths to `VARCHAR2`, so the OCI8 builder must cast them. Remove this skip once it does.');
+        }
+
+        $table = 'type_test';
+
+        $builder = $this->db->table($table);
+        $builder->truncate();
+
+        for ($i = 1; $i < 3; $i++) {
+            $builder->insert([
+                'type_varchar'  => 'test' . $i,
+                'type_char'     => 'char' . $i,
+                'type_text'     => 'text',
+                'type_smallint' => 32767,
+                'type_integer'  => 2_147_483_647,
+                'type_bigint'   => 9_223_372_036_854_775_807,
+                'type_float'    => 10.1,
+                'type_numeric'  => 123.23,
+                'type_date'     => '2023-12-0' . $i,
+                'type_datetime' => '2023-12-21 12:00:00',
+            ]);
+        }
+
+        $this->db->table($table)->updateBatch([
+            ['type_char' => 'char1     X', 'type_text' => 'changed'],
+            ['type_char' => 'char2', 'type_text' => 'changed'],
+        ], 'type_char');
+
+        $this->seeInDatabase($table, ['type_varchar' => 'test1', 'type_text' => 'text']);
+        $this->seeInDatabase($table, ['type_varchar' => 'test2', 'type_text' => 'changed']);
+    }
+
+    public function testUpdateBatchWithMappedUpdateFieldsAndMixedValueTypes(): void
+    {
+        if ($this->db->DBDriver === 'SQLSRV') {
+            $this->markTestSkipped('SQL Server cannot compare `text` columns with `=`.');
+        }
+
+        if ($this->db->DBDriver === 'OCI8') {
+            $this->markTestSkipped('TODO: the OCI8 builder does not cast mixed `UNION ALL` values yet. Remove this skip once it does.');
+        }
+
+        $table = 'type_test';
+
+        $builder = $this->db->table($table);
+        $builder->truncate();
+
+        for ($i = 1; $i < 3; $i++) {
+            $builder->insert([
+                'type_varchar'  => 'test' . $i,
+                'type_char'     => 'char' . $i,
+                'type_text'     => 'text',
+                'type_smallint' => 32767,
+                'type_integer'  => 2_147_483_647,
+                'type_bigint'   => 9_223_372_036_854_775_807,
+                'type_float'    => 10.1,
+                'type_numeric'  => 123.23,
+                'type_date'     => '2023-12-0' . $i,
+                'type_datetime' => '2023-12-21 12:00:00',
+            ]);
+        }
+
+        $this->db->table($table)
+            ->setData([
+                ['type_varchar' => 'test1', 'text' => 'Example'],
+                ['type_varchar' => 'test2', 'text' => 587],
+            ], null, 'data')
+            ->updateFields(['type_text' => 'text'])
+            ->onConstraint('type_varchar')
+            ->updateBatch();
+
+        $this->seeInDatabase($table, ['type_varchar' => 'test1', 'type_text' => 'Example']);
+        $this->seeInDatabase($table, ['type_varchar' => 'test2', 'type_text' => '587']);
+    }
+
+    public function testUpdateBatchKeepsSourceValueForColumnsOfDifferentTypes(): void
+    {
+        if ($this->db->DBDriver === 'SQLSRV') {
+            $this->markTestSkipped('SQL Server cannot compare `text` columns with `=`.');
+        }
+
+        $table = 'type_test';
+
+        $builder = $this->db->table($table);
+        $builder->truncate();
+
+        $builder->insert([
+            'type_varchar'  => 'test1',
+            'type_char'     => 'char1',
+            'type_text'     => 'text',
+            'type_smallint' => 32767,
+            'type_integer'  => 2_147_483_647,
+            'type_bigint'   => 9_223_372_036_854_775_807,
+            'type_float'    => 10.1,
+            'type_numeric'  => 123.23,
+            'type_date'     => '2023-12-01',
+            'type_datetime' => '2023-12-21 12:00:00',
+        ]);
+
+        $this->db->table($table)
+            ->setData([['type_varchar' => 'test1', 'value' => 1.4]], null, 'data')
+            ->updateFields(['type_integer' => 'value', 'type_text' => 'value'])
+            ->onConstraint('type_varchar')
+            ->updateBatch();
+
+        $this->seeInDatabase($table, ['type_varchar' => 'test1', 'type_text' => '1.4']);
+    }
+
     public function testUpdateWithWhereSameColumn(): void
     {
         $this->db->table('user')->update(['country' => 'CA'], ['country' => 'US']);
diff --git a/user_guide_src/source/changelogs/v4.7.5.rst b/user_guide_src/source/changelogs/v4.7.5.rst
index 34dc4dcf41eb..45416eef17da 100644
--- a/user_guide_src/source/changelogs/v4.7.5.rst
+++ b/user_guide_src/source/changelogs/v4.7.5.rst
@@ -55,6 +55,7 @@ Bugs Fixed
 - **Database:** Fixed a bug where rebuilding a SQLite3 table (e.g., ``Forge::dropColumn()``, ``Forge::modifyColumn()``, ``Forge::dropForeignKey()`` and ``Forge::dropPrimaryKey()``) corrupted the table names referenced by its foreign keys when ``DBPrefix`` was set.
 - **Database:** Fixed a bug where Postgre query failures were silently ignored when ``DBDebug`` was enabled and PHP warnings were disabled. A ``DatabaseException`` is now thrown.
 - **Database:** Fixed a bug where ``getFieldData()`` failed for a schema-qualified table name on Postgre, SQLSRV and SQLite3, and where ``protectIdentifiers()`` prefixed an already protected segment of a dotted identifier a second time.
+- **Database:** Fixed a bug where ``updateBatch()`` and ``deleteBatch()`` failed on PostgreSQL when the rows supplied different PHP types (e.g., a string and an integer) for the same column, because the ``UNION ALL`` subquery values were not cast to the column type.
 - **Debug:** Fixed a bug where ``Timer::start()`` treated ``0.0`` as an empty value and substituted the current time.
 - **Files:** Fixed a bug where ``File::move()`` and ``UploadedFile::move()`` set executable and overly permissive file permissions (``0777 & ~umask()`` instead of ``0666 & ~umask()``), and ``UploadedFile::move()`` targeted the parent directory instead of the destination file for ``chmod()``.
 - **Helpers:** Fixed a bug where ``get_dir_file_info()`` returned incomplete entries for subdirectories and missing files instead of omitting them.