Enhance Database initialization how to guide

See gh-21077

Author: nikmanzotti

spring-boot-project/spring-boot-docs/src/main/asciidoc/howto.adoc

@@ -1949,23 +1949,28 @@ For example, you might choose to set it to the vendor name of the database (`hsq
 
 [NOTE]
 ====
-Spring Boot automatically creates the schema of an embedded `DataSource`.
+When only basic SQL scripts are used, Spring Boot automatically creates the schema of an embedded `DataSource`.
 This behavior can be customized by using the configprop:spring.datasource.initialization-mode[] property.
 For instance, if you want to always initialize the `DataSource` regardless of its type:
 
 [indent=0,subs="verbatim,quotes,attributes"]
 ----
 	spring.datasource.initialization-mode=always
 ----
+In a JPA-based app, you can choose to let Hibernate create the schema or use `schema.sql`, but you cannot do both.
+Make sure to disable `spring.jpa.hibernate.ddl-auto` if you use `schema.sql`.
+[indent=0,subs="verbatim,quotes,attributes"]
+----
+	spring.jpa.hibernate.ddl-auto=none
+----
+If you are using a <<spring-boot-features.adoc#howto-use-a-higher-level-database-migration-tool,Higher-level Database Migration Tool>>, like Flyway or Liquibase, you cannot use basic SQL scripts to create and initialize the schema.
+In this situation, if `schema.sql` and `data.sql` are present, they will be ignored. It is not possible to use a Database Migration Tool to manage schema creation, and a basic SQL script to initialize it.
 ====
 
 By default, Spring Boot enables the fail-fast feature of the Spring JDBC initializer.
 This means that, if the scripts cause exceptions, the application fails to start.
 You can tune that behavior by setting `spring.datasource.continue-on-error`.
 
-NOTE: In a JPA-based app, you can choose to let Hibernate create the schema or use `schema.sql`, but you cannot do both.
-Make sure to disable `spring.jpa.hibernate.ddl-auto` if you use `schema.sql`.
-
 
 
 [[howto-initialize-a-spring-batch-database]]
@@ -2056,6 +2061,13 @@ With that setup, migrations in `dev/db/migration` run only when the `dev` profil
 ==== Execute Liquibase Database Migrations on Startup
 To automatically run Liquibase database migrations on startup, add the `org.liquibase:liquibase-core` to your classpath.
 
+[NOTE]
+====
+When you add the `org.liquibase:liquibase-core` to your classpath, by default database migrations will run for both during application startup and before your tests run.
+This behavior can be customized by using the configprop:spring.liquibase.enabled[] property, setting different values in the `main` and `test` folders.
+It is not possible to use two different ways to initialize the database (e.g. Liquibase for application startup, JPA for test runs).
+====
+
 By default, the master change log is read from `db/changelog/db.changelog-master.yaml`, but you can change the location by setting `spring.liquibase.change-log`.
 In addition to YAML, Liquibase also supports JSON, XML, and SQL change log formats.
 
@@ -2064,7 +2076,7 @@ If you need to use a different `DataSource`, you can create one and mark its `@B
 If you do so and you want two data sources, remember to create another one and mark it as `@Primary`.
 Alternatively, you can use Liquibase's native `DataSource` by setting `spring.liquibase.[url,user,password]` in external properties.
 Setting either `spring.liquibase.url` or `spring.liquibase.user` is sufficient to cause Liquibase to use its own `DataSource`.
-If any of the three properties has not be set, the value of its equivalent `spring.datasource` property will be used.
+If any of the three properties has not been set, the value of its equivalent `spring.datasource` property will be used.
 
 See {spring-boot-autoconfigure-module-code}/liquibase/LiquibaseProperties.java[`LiquibaseProperties`] for details about available settings such as contexts, the default schema, and others.