feat: Enhance testing documentation with detailed instructions for database-specific testing and local development setup using docker.

CHANGELOG.md

@@ -1,5 +1,5 @@
 # Change Log
 
-## 0.1.0 July 4, 2025
+## 0.1.0 July 8, 2025
 
 - Initial release

docs/testing.md

@@ -41,10 +41,105 @@ The code is statically analyzed with [PHPStan](https://phpstan.org/). To run sta
 composer run static
 ```
 
-## Unit tests
+## Unit Tests
 
 The code is tested with [PHPUnit](https://phpunit.de/). To run tests.
 
-```
+```shell
 composer run test
 ```
+
+### Database Testing
+
+This package supports testing with multiple database systems to ensure compatibility across different environments.
+
+- **MySQL** (8.0, 8.4, latest)
+- **Oracle** (23)
+- **PostgreSQL** (15, 16, 17)
+- **SQL Server** (2022-latest)
+- **SQLite** (default, in-memory) — No setup required
+
+#### Database-Specific Testing
+
+Run tests against specific database systems using PHPUnit groups.
+
+```shell
+# MySQL
+./vendor/bin/phpunit --group mysql
+
+# Oracle
+./vendor/bin/phpunit --group oci
+
+# PostgreSQL  
+./vendor/bin/phpunit --group pgsql
+
+# SQL Server
+./vendor/bin/phpunit --group mssql
+
+# SQLite (default - in-memory database)
+./vendor/bin/phpunit --group sqlite
+```
+
+#### Local Development Setup
+
+For local testing with real databases, you can use Docker.
+
+##### MySQL
+```shell
+docker run -d --name mysql-test \
+  -e MYSQL_ROOT_PASSWORD=root \
+  -e MYSQL_DATABASE=yiitest \
+  -p 3306:3306 \
+  mysql:8.4
+
+# Configure your database connection and run.
+./vendor/bin/phpunit --group mysql
+```
+
+##### Oracle
+```shell
+docker run -d --name oracle-test \
+  -e ORACLE_PASSWORD=root \
+  -e ORACLE_DATABASE=yiitest \
+  -p 1521:1521 \
+  gvenzl/oracle-free:23
+
+# Configure your database connection and run.
+./vendor/bin/phpunit --group oci
+```
+
+##### PostgreSQL
+```shell
+docker run -d --name pgsql-test \
+  -e POSTGRES_PASSWORD=root \
+  -e POSTGRES_DB=yiitest \
+  -e POSTGRES_USER=root \
+  -p 5432:5432 \
+  postgres:17
+
+# Configure your database connection and run.
+./vendor/bin/phpunit --group pgsql
+```
+
+##### SQL Server
+```shell
+docker run -d --name mssql-test \
+  -e ACCEPT_EULA=Y \
+  -e 'SA_PASSWORD=YourStrong!Passw0rd' \
+  -e MSSQL_PID=Developer \
+  -p 1433:1433 \
+  mcr.microsoft.com/mssql/server:2022-latest
+
+# Create test database.
+docker exec -it mssql-test /opt/mssql-tools18/bin/sqlcmd \
+  -C -S localhost -U SA -P 'YourStrong!Passw0rd' \
+  -Q "CREATE DATABASE yiitest;"
+
+# Configure your database connection and run.
+./vendor/bin/phpunit --group mssql
+```
+
+##### SQLite
+```shell
+./vendor/bin/phpunit --group sqlite
+```