[[jdbc-packages]]
= Package Hierarchy

The Spring Framework's JDBC abstraction framework consists of four different packages:

* `core`: The `org.springframework.jdbc.core` package contains the `JdbcTemplate` class
and its various callback interfaces, plus a variety of related classes. A subpackage
named `org.springframework.jdbc.core.simple` contains the `SimpleJdbcInsert` and
`SimpleJdbcCall` classes. Another subpackage named
`org.springframework.jdbc.core.namedparam` contains the `NamedParameterJdbcTemplate`
class and the related support classes. See
xref:data-access/jdbc/core.adoc[Using the JDBC Core Classes to Control Basic JDBC Processing and Error Handling],
xref:data-access/jdbc/advanced.adoc[JDBC Batch Operations], and
xref:data-access/jdbc/simple.adoc[Simplifying JDBC Operations with the `SimpleJdbc` Classes].

* `datasource`: The `org.springframework.jdbc.datasource` package contains a utility class
for easy `DataSource` access and various simple `DataSource` implementations that you can
use for testing and running unmodified JDBC code outside of a Jakarta EE container. A subpackage
named `org.springframework.jdbc.datasource.embedded` provides support for creating
embedded databases by using Java database engines, such as HSQL, H2, and Derby. See
xref:data-access/jdbc/connections.adoc[Controlling Database Connections] and
xref:data-access/jdbc/embedded-database-support.adoc[Embedded Database Support].

* `object`: The `org.springframework.jdbc.object` package contains classes that represent
RDBMS queries, updates, and stored procedures as thread-safe, reusable objects. See
xref:data-access/jdbc/object.adoc[Modeling JDBC Operations as Java Objects]. This style
results in a more object-oriented approach, although objects returned by queries are
naturally disconnected from the database. This higher-level of JDBC abstraction depends
on the lower-level abstraction in the `org.springframework.jdbc.core` package.

* `support`: The `org.springframework.jdbc.support` package provides `SQLException`
translation functionality and some utility classes. Exceptions thrown during JDBC processing
are translated to exceptions defined in the `org.springframework.dao` package. This means
that code using the Spring JDBC abstraction layer does not need to implement JDBC or
RDBMS-specific error handling. All translated exceptions are unchecked, which gives you
the option of catching the exceptions from which you can recover while letting other
exceptions be propagated to the caller. See
xref:data-access/jdbc/core.adoc#jdbc-SQLExceptionTranslator[Using `SQLExceptionTranslator`].
