I am starting my spring container in validate mode
autoddl=validate
I am getting a validation exception like this
Caused by: org.hibernate.tool.schema.spi.SchemaManagementException: Schema-
validation: wrong column type encountered in column [amount] in table [Balance];
found [numeric (Types#NUMERIC)], but expecting [int8 (Types#BIGINT)]
and my DDL script goes like this
CREATE TABLE Balance(stratr VARCHAR(25), histFromDate TIMESTAMP WITHOUT TIME
ZONE,amount numeric(11, 0))
and my attribute in JPA entity goes like this
#Column(name="amount", precision=11, scale=0) //have specified precision and scale
private Long amount ;
where I have used import javax.persistence.Column.Since I have annotated the exact precision and scale, Shouldn't hibernate validate with these info that I have provided through the column annotation? What could have I missed ?
I cannot do the following
#Column(
columnDefinition = "NUMERIC(11,0)"
)
private Long amount;
because I don't know the data store of this JPA entity.
I also tried generating the script by the following property
<prop key="javax.persistence.schema-generation.scripts.action">drop-and-create</prop>
<prop key="javax.persistence.schema-generation.scripts.create-target">./l/create.sql</prop>
<prop key="javax.persistence.schema-generation.scripts.drop-target">./l/drop.sql</prop>
This is also generating as int8 and not numeric(11,0). What can be done to solve this ?
It's really quite difficult to grasp what you're trying to accomplish, but if I understood correctly:
you want to keep your application portable by not fixing the column definition on the entity level to be NUMERIC(11,0), which would make it Postgres-specific
at the same time, you want your column to use NUMERIC(11,0) for Postgres and not INT8 that Hibernate would normally use for a Long in Postgres (and is hoping to find in your schema upon validation)
In short, you want a per-database customization that is not reflected in your entity mapping. The only way to accomplish that is to customize the dialect that Hibernate is using for your version of Postgres. What you need to do is:
determine which dialect version is being selected for your Postgres database (it will be one of the following: PostgresPlusDialect, PostgreSQL81Dialect, PostgreSQL82Dialect, PostgreSQL91Dialect, PostgreSQL92Dialect,PostgreSQL93Dialect, PostgreSQL94Dialect, PostgreSQL95Dialect, PostgreSQL9Dialect)
extend from that class, adding the following definition:
public MyCustomPostgresDialect() {
super();
registerColumnType(Types.BIGINT, "NUMERIC(11, 0)");
}
(If you want to be able to control the precision and scale using #Column(precision = ..., scale = ...), use registerColumnType(Types.BIGINT, "NUMERIC($p, $s)") instead)
add the hibernate.dialect property to persistence.xml, pointing to the fully qualified class name of your custom dialect
Note that this will, of course, affect all Long properties in your data model, not just the specific field in question.
I can think on only reason is because in your entity amount type is Long but in JPA creation script your DDL specified as amount numeric(11, 0) here second param suggest decimal precision.
As you can see java tries to enter data in Long type (ie. 10.0000), similar to BigInt in Database but database does not accept such decimal value being type numeric (11,0)
You should be able to resolve it by either changing your java code to have entity amount type int or change DDL to have scaleInt. ie. NUMERIC(11,5).
However best bet would be to have DECIMAL type for any non Integer type.
http://www.h2database.com/html/datatypes.html#decimal_type
I use Hibernate Reverse Engineering to automatically create classes from a database scheme. DB server is MSSQL 2008. This database is designed by a partner and could potentially change without notice. Thus I'd like to have Hibernate validate the scheme on startup, wich in my opinion should work out of the box. But it doesn't:
org.hibernate.HibernateException: Wrong column type in somedb.dbo.ASVC_S for column SomeCol. Found: decimal, expected: numeric(18,0)
The generated enttity class looks like this:
#Column(name="SomeCol", precision=18)
public BigDecimal getSomeCol() {
return this.someCol;
}
Is my assumption that reveng creates classes that can be validated against the schema wrong? Should I skip validation and hope that during runtime everything's OK? Annotating the classes after generating them or maintaining an entry for each class in my reveng.xml mapping file is not an option - too many classes ;)
hibernate-tools is version 4.0.0-CR1.
I turned off the EclipseLink cache because I'm modifying data externally and don't want the hassle of having to manually refresh everything. Apparently, this is the correct way to switch off the cache in persistence.xml to avoid object identity issues:
<properties>
<property name="eclipselink.cache.shared.default" value="false"/>
</properties>
And here's the exception:
Exception [EclipseLink-6094] (Eclipse Persistence Services - 2.3.0.v20110604-r9504): org.eclipse.persistence.exceptions.QueryException
Exception Description: The parameter name [patient_id] in the query's selection criteria does not match any parameter name defined in the query.
Query: ReadAllQuery(name="file:/C:/dev/repsitory/trunk/java/server/myapp-server/myapp-server-ear/target/gfdeploy/au.com.myapp_myapp-server-ear_ear_1.0-SNAPSHOT/myapp-server-ejb-1.0-SNAPSHOT_jar/_myappPU590288694" referenceClass=PatientRecord sql="SELECT active, new_patient, patient_id_external, rank, patient_id, clinic_system_id FROM postgres.myapp.patient_record WHERE (patient_id = ?)")
I can't even understand the exception message. It's talking about parameter names in the query, but JDBC parameters aren't named.
Any idea how to work around this without switching the cache back on?
As it turns out, I had created an instance of PatientRecord that included one or two detached objects (many-to-one from PatientRecord's perspective). This wasn't a problem with caching on because those objects never became detached.
I merged the objects first then it worked.
I'm working on a java project full of Hibernate (3.3.1) mapping files that have the following sort of declaration for most domain objects.
<property name="dateCreated" generated="insert">
<column name="date_created" default="getdate()" />
</property>
The problem here is that getdate() is an MSSQL specific function, and when I'm using something like H2 to test subsections of the project, H2 screams that
getdate()
isn't a recognized function. It's own timestamping function is
current_timestamp().
I'd like to be able to keep working with H2 for testing, and wanted to know whether there was a way of telling Hibernate "use this database's own mechanism for retrieving the current timestamp". With H2, I've come up with the following solution.
CREATE ALIAS getdate AS $$ java.util.Date now() { return new java.util.Date(); } $$;
CALL getdate();
It works, but is obviously H2 specific.
I've tried extending H2Dialect and registering the function getdate(), but that doesn't seem to be invoked when Hibernate is creating tables. Is it possible to abstract the idea of a default timestamp away from the specific database engine?
Could you try the following (without generated since your database is not generating the value):
<column name="DATE_CREATED" sql-type="timestamp" default="CURRENT_TIMESTAMP"/>
Have you tried using a <timestamp> mapping inside your <class>?
The docs aren't very clear but it sounds like this should result in mapping a column whose value is a timestamp.
You can specify if Hibernate should use a database generated value by setting either generated="insert" or generated="always".
I really want to know more about the update, export and the values that could be given to hibernate.hbm2ddl.auto
I need to know when to use the update and when not? And what is the alternative?
These are changes that could happen over DB:
new tables
new columns in old tables
columns deleted
data type of a column changed
a type of a column changed its attributes
tables dropped
values of a column changed
In each case what is the best solution?
From the community documentation:
hibernate.hbm2ddl.auto Automatically validates or exports schema DDL to the database when the SessionFactory is created. With create-drop, the database schema will be dropped when the SessionFactory is closed explicitly.
e.g. validate | update | create | create-drop
So the list of possible options are,
validate: validate the schema, makes no changes to the database.
create-only: database creation will be generated.
drop: database dropping will be generated.
update: update the schema.
create: creates the schema, destroying previous data.
create-drop: drop the schema when the SessionFactory is closed explicitly, typically when the application is stopped.
none: does nothing with the schema, makes no changes to the database
These options seem intended to be developers tools and not to facilitate any production level databases, you may want to have a look at the following question; Hibernate: hbm2ddl.auto=update in production?
There's also the value of none to disable it entirely.
The configuration property is called hibernate.hbm2ddl.auto
In our development environment we set hibernate.hbm2ddl.auto=create-drop to drop and create a clean database each time we deploy, so that our database is in a known state.
In theory, you can set hibernate.hbm2ddl.auto=update to update your database with changes to your model, but I would not trust that on a production database. An earlier version of the documentation said that this was experimental, at least; I do not know the current status.
Therefore, for our production database, do not set hibernate.hbm2ddl.auto - the default is to make no database changes. Instead, we manually create an SQL DDL update script that applies changes from one version to the next.
First, the possible values for the hbm2ddl configuration property are the following ones:
none - No action is performed. The schema will not be generated.
create-only - The database schema will be generated.
drop - The database schema will be dropped.
create - The database schema will be dropped and created afterward.
create-drop - The database schema will be dropped and created afterward. Upon closing the SessionFactory, the database schema will be dropped.
validate - The database schema will be validated using the entity mappings.
update - The database schema will be updated by comparing the existing database schema with the entity mappings.
The hibernate.hbm2ddl.auto="update" is convenient but less flexible if you plan on adding functions or executing some custom scripts.
So, The most flexible approach is to use Flyway.
However, even if you use Flyway, you can still generate the initial migration script using hbm2ddl.
I would use liquibase for updating your db. hibernate's schema update feature is really only o.k. for a developer while they are developing new features. In a production situation, the db upgrade needs to be handled more carefully.
Although it is quite an old post but as i did some research on the topic so thought of sharing it.
hibernate.hbm2ddl.auto
As per the documentation it can have four valid values:
create | update | validate | create-drop
Following is the explanation of the behaviour shown by these value:
create :- create the schema, the data previously present (if there) in the schema is lost
update:- update the schema with the given values.
validate:- validate the schema. It makes no change in the DB.
create-drop:- create the schema with destroying the data previously present(if there). It also drop the database schema when the SessionFactory is closed.
Following are the important points worth noting:
In case of update, if schema is not present in the DB then the schema is created.
In case of validate, if schema does not exists in DB, it is not created. Instead, it will throw an error:- Table not found:<table name>
In case of create-drop, schema is not dropped on closing the session. It drops only on closing the SessionFactory.
In case if i give any value to this property(say abc, instead of above four values discussed above) or it is just left blank. It shows following behaviour:
-If schema is not present in the DB:- It creates the schema
-If schema is present in the DB:- update the schema.
hibernate.hbm2ddl.auto automatically validates and exports DDL to the schema when the sessionFactory is created.
By default, it does not perform any creation or modification automatically on DB. If the user sets one of the below values then it is doing DDL schema changes automatically.
create - doing creating a schema
<entry key="hibernate.hbm2ddl.auto" value="create">
update - updating existing schema
<entry key="hibernate.hbm2ddl.auto" value="update">
validate - validate existing schema
<entry key="hibernate.hbm2ddl.auto" value="validate">
create-drop - create and drop the schema automatically when a session is starts and ends
<entry key="hibernate.hbm2ddl.auto" value="create-drop">
If you don't want to use Strings in your app and are looking for predefined constants have a look at org.hibernate.cfg.AvailableSettings class included in the Hibernate JAR, where you'll find a constant for all possible settings. In your case for example:
/**
* Auto export/update schema using hbm2ddl tool. Valid values are <tt>update</tt>,
* <tt>create</tt>, <tt>create-drop</tt> and <tt>validate</tt>.
*/
String HBM2DDL_AUTO = "hibernate.hbm2ddl.auto";
validate: validates the schema, no change happens to the database.
update: updates the schema with current execute query.
create: creates new schema every time, and destroys previous data.
create-drop: drops the schema when the application is stopped or SessionFactory is closed explicitly.
I Think you should have to concentrate on the
SchemaExport Class
this Class Makes Your Configuration Dynamic
So it allows you to choose whatever suites you best...
Checkout [SchemaExport]
validate: It validates the schema and makes no changes to the DB.
Assume you have added a new column in the mapping file and perform the insert operation, it will throw an Exception "missing the XYZ column" because the existing schema is different than the object you are going to insert. If you alter the table by adding that new column manually then perform the Insert operation then it will definitely insert all columns along with the new column to the Table.
Means it doesn't make any changes/alters the existing schema/table.
update: it alters the existing table in the database when you perform operation.
You can add or remove columns with this option of hbm2ddl.
But if you are going to add a new column that is 'NOT NULL' then it will ignore adding that particular column to the DB. Because the Table must be empty if you want to add a 'NOT NULL' column to the existing table.
Since 5.0, you can now find those values in a dedicated Enum: org.hibernate.boot.SchemaAutoTooling (enhanced with value NONE since 5.2).
Or even better, since 5.1, you can also use the org.hibernate.tool.schema.Action Enum which combines JPA 2 and "legacy" Hibernate DDL actions.
But, you cannot yet configure a DataSource programmatically with this. It would be nicer to use this combined with org.hibernate.cfg.AvailableSettings#HBM2DDL_AUTO but the current code expect a String value (excerpt taken from SessionFactoryBuilderImpl):
this.schemaAutoTooling = SchemaAutoTooling.interpret( (String) configurationSettings.get( AvailableSettings.HBM2DDL_AUTO ) );
… and internal enum values of both org.hibernate.boot.SchemaAutoToolingand org.hibernate.tool.schema.Action aren't exposed publicly.
Hereunder, a sample programmatic DataSource configuration (used in ones of my Spring Boot applications) which use a gambit thanks to .name().toLowerCase() but it only works with values without dash (not create-drop for instance):
#Bean(name = ENTITY_MANAGER_NAME)
public LocalContainerEntityManagerFactoryBean internalEntityManagerFactory(
EntityManagerFactoryBuilder builder,
#Qualifier(DATA_SOURCE_NAME) DataSource internalDataSource) {
Map<String, Object> properties = new HashMap<>();
properties.put(AvailableSettings.HBM2DDL_AUTO, SchemaAutoTooling.CREATE.name().toLowerCase());
properties.put(AvailableSettings.DIALECT, H2Dialect.class.getName());
return builder
.dataSource(internalDataSource)
.packages(JpaModelsScanEntry.class, Jsr310JpaConverters.class)
.persistenceUnit(PERSISTENCE_UNIT_NAME)
.properties(properties)
.build();
}
To whomever searching for default value...
It is written in the source code at version 2.0.5 of spring-boot and 1.1.0 at JpaProperties:
/**
* DDL mode. This is actually a shortcut for the "hibernate.hbm2ddl.auto"
* property. Defaults to "create-drop" when using an embedded database and no
* schema manager was detected. Otherwise, defaults to "none".
*/
private String ddlAuto;
With all above said...
Notice this property is called dll.auto and should only control dll operations(create/drop schema/table), I found surprisingly that it has to do with dml, too: only update will allow insert data, which is dml operation.
Got caught by this when trying to populate data into a in-memory database; only update works.