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add a summary section to the doc

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Gavin 2023-05-15 16:50:05 +02:00
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documentation/src/main/asciidoc/introduction/Configuration.adoc
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@ -396,6 +396,7 @@ Writing your own `PhysicalNamingStrategy` and/or `ImplicitNamingStrategy` is an
Please refer to the Javadoc for these interfaces for more information about the division of responsibility between them.
====
[[nationalized-chars]]
=== Nationalized character data in SQL Server
_By default,_ SQL Server's `char` and `varchar` types don't accommodate Unicode data. But a Java string may contain any Unicode character. So, if you're working with SQL Server, you might need to force Hibernate to use the `nchar` and `nvarchar` column types.

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documentation/src/main/asciidoc/introduction/Mapping.adoc
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@ -731,6 +731,49 @@ runtimeOnly 'com.fasterxml.jackson.core:jackson-databind:{jacksonVersion}'
Now the `name` column of the `Author` table will have the type `jsonb`, and Hibernate will automatically use Jackson to serialize a `Name` to and from JSON format.
[[miscellaneous-mappings]]
=== Summary of SQL column type mappings
So, as we've seen, there are quite a few annotations that affect the mapping of Java types to SQL column types in DDL.
Here we summarize the ones we've just seen in the second half of this chapter, along with some we already mentioned in earlier chapters.
.Annotations for mapping SQL column types
[cols=",3"]
|===
| Annotation | Interpretation
| `@Enumerated` | Specify how an `enum` type should be persisted
| `@Nationalized` | Use a nationalized character type: `NCHAR`, `NVARCHAR`, or `NCLOB`
| `@Lob` 💀 | Use JDBC LOB APIs to read and write the annotated attribute
| `@Array` | Map a collection to a SQL `ARRAY` type of the specified length
| `@Struct` | Map an embeddable to a SQL UDT with the given name
| `@TimeZoneStorage` | Specify how the time zone information should be persisted
| `@JdbcType` or `@JdbcTypeCode` | Use an implementation of `JdbcType` to map an arbitrary SQL type
|===
In addition, there are some configuration properties which have a _global_ affect on how basic types map to SQL column types:
.Type mapping settings
[cols=",2"]
|===
| Configuration property name | Purpose
| `hibernate.use_nationalized_character_data` | Enable use of nationalized character types by default
| `hibernate.type.preferred_boolean_jdbc_type` | Specify the default SQL column type for mapping `boolean`
| `hibernate.type.preferred_uuid_jdbc_type` | Specify the default SQL column type for mapping `UUID`
| `hibernate.type.preferred_duration_jdbc_type` | Specify the default SQL column type for mapping `Duration`
| `hibernate.type.preferred_instant_jdbc_type` | Specify the default SQL column type for mapping `Instant`
| `hibernate.timezone.default_storage` | Specify the default strategy for storing time zone information
|===
[TIP]
====
These are _global_ settings and thus quite clumsy.
We recommend against messing with any of these settings unless you have a really good reason for it.
====
There's one more topic we would like to cover in this chapter.
[[mapping-formulas]]
=== Mapping to formulas