Reorganize and modularize the Testing chapter in the reference manual

Closes gh-29522

framework-docs/src/docs/asciidoc/testing/testing-support-jdbc.adoc

@@ -0,0 +1,35 @@
+[[integration-testing-support-jdbc]]
+= JDBC Testing Support
+
+[[integration-testing-support-jdbc-test-utils]]
+== JdbcTestUtils
+
+The `org.springframework.test.jdbc` package contains `JdbcTestUtils`, which is a
+collection of JDBC-related utility functions intended to simplify standard database
+testing scenarios. Specifically, `JdbcTestUtils` provides the following static utility
+methods.
+
+* `countRowsInTable(..)`: Counts the number of rows in the given table.
+* `countRowsInTableWhere(..)`: Counts the number of rows in the given table by using the
+  provided `WHERE` clause.
+* `deleteFromTables(..)`: Deletes all rows from the specified tables.
+* `deleteFromTableWhere(..)`: Deletes rows from the given table by using the provided
+  `WHERE` clause.
+* `dropTables(..)`: Drops the specified tables.
+
+[TIP]
+====
+<<testcontext-support-classes-junit4, `AbstractTransactionalJUnit4SpringContextTests`>>
+and <<testcontext-support-classes-testng, `AbstractTransactionalTestNGSpringContextTests`>>
+provide convenience methods that delegate to the aforementioned methods in
+`JdbcTestUtils`.
+====
+
+[[integration-testing-support-jdbc-embedded-database]]
+== Embedded Databases
+
+The `spring-jdbc` module provides support for configuring and launching an embedded
+database, which you can use in integration tests that interact with a database.
+For details, see <<data-access.adoc#jdbc-embedded-database-support, Embedded Database
+Support>> and <<data-access.adoc#jdbc-embedded-database-dao-testing, Testing Data Access
+Logic with an Embedded Database>>.