10 files declare their use of IntegrityConstraintViolationException

BatchBidSerialUpdateTest.php in core/modules/system/tests/src/Functional/Update/BatchBidSerialUpdateTest.php
DatabaseLockBackend.php in core/lib/Drupal/Core/Lock/DatabaseLockBackend.php
DriverSpecificSchemaTestBase.php in core/tests/Drupal/KernelTests/Core/Database/DriverSpecificSchemaTestBase.php
EntityDefinitionUpdateTest.php in core/tests/Drupal/KernelTests/Core/Entity/EntityDefinitionUpdateTest.php
ExceptionHandler.php in core/modules/mysql/src/Driver/Database/mysql/ExceptionHandler.php
form.inc in core/includes/form.inc
Functions for form and batch generation and processing.
InsertTest.php in core/tests/Drupal/KernelTests/Core/Database/InsertTest.php
InvalidDataTest.php in core/tests/Drupal/KernelTests/Core/Database/InvalidDataTest.php
Merge.php in core/lib/Drupal/Core/Database/Query/Merge.php
UpdateTest.php in core/tests/Drupal/KernelTests/Core/Database/UpdateTest.php

Buggy or inaccurate documentation? Please file an issue. Need support? Need help programming? Connect with the Drupal community.