Posts (page 118)
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10 min readTo handle JSON values from a native query in Hibernate, you can define a custom data type for mapping JSON values in your entity class. You can use the JsonNode type from the Jackson library to represent the JSON values.When executing a native query that returns JSON values, you can specify the return type as JsonNode in the createNativeQuery method call. You can then process the JSON values using the methods provided by the JsonNode class.
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5 min readIn Oracle SQL, the JOIN operator is used to combine rows from two or more tables based on a related column between them. There are different types of joins such as INNER JOIN, LEFT JOIN (or LEFT OUTER JOIN), RIGHT JOIN (or RIGHT OUTER JOIN), and FULL JOIN (or FULL OUTER JOIN).To use the JOIN operator in Oracle SQL, you need to specify the tables you want to join followed by the specific type of join and the condition on which the tables should be joined.
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4 min readTo get specific columns from a Hibernate join, you can use the Projections class from the Hibernate Criteria API. By using Projections, you can specify the columns that you want to retrieve from the joined entities. This allows you to avoid retrieving all columns from the joined tables and only get the data that you actually need. Additionally, you can also use aliases to give meaningful names to the columns that you retrieve, making it easier to work with the results.
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4 min readTo set configuration using application.properties in hibernate, you can specify the configuration properties directly in the application.properties file in your Spring Boot project. You can configure properties such as the database URL, username, password, dialect, show_sql, and many others by prefixing them with spring.jpa.hibernate in the application.properties file. For example, you can set the database URL by adding spring.jpa.hibernate.jdbc.
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6 min readTo set a parameter to null value in Java with Hibernate, you can use the setParameter method on the Query interface. When setting a parameter to null, you can simply pass null as the value for the parameter. For example, if you have a query that requires a parameter called "name" to be null, you can set it like this: Query query = session.createQuery("FROM User WHERE name = :name"); query.setParameter("name", null); List<User> users = query.
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7 min readTo remove entities from a many-to-many relationship in Hibernate, you need to first load the entities from the database and then remove the association between them. This involves removing the association records from the join table that links the two entities together.You can do this by getting the entities from their respective repositories, removing the association from one side of the relationship (e.g.
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3 min readTo save a timestamp in a single column using Hibernate, you can map the timestamp attribute of your entity class to a single column in the database table. This can be achieved by using the @Column annotation on the timestamp attribute with the specified column name as its parameter. Hibernate will map the timestamp value to that column in the table.
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7 min readTo map only a single column with Hibernate, you can use the @Column annotation on the specific field in your entity class. This annotation allows you to specify the name of the column in the database that the field should be mapped to. By default, Hibernate will map the field to a column with the same name as the field itself, but you can override this behavior by specifying a different column name in the @Column annotation.
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5 min readTo add a WHERE clause on a custom type in Hibernate, you can use the @Where annotation. This annotation allows you to specify conditions that should be added to the SQL WHERE clause when querying for entities of a specific type.First, you need to define a custom type for your entity, if you haven't already. Then, you can add the @Where annotation to your entity class, specifying the condition that should be applied.
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5 min readOne way to enforce table creation order in Hibernate is by specifying the order in which tables should be created using the @OrderColumn annotation. This annotation can be applied to a list or a map attribute in an entity class to define the order in which the elements should be stored in the database.Another approach is to use the hibernate.hbm2ddl.auto property in the Hibernate configuration file to specify the order in which tables should be created.
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6 min readWhen working with Hibernate, we may encounter situations where there are columns in a database table that are not defined in the Hibernate entity class. In such cases, Hibernate provides a way to handle these unknown columns using a feature called "Dynamic Models."With Dynamic Models, we can use a Map to represent the unknown columns in the entity class.
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5 min readHibernate cache properties can be set through the hibernate.cfg.xml configuration file or programmatically using the SessionFactory object.To set cache properties in the hibernate.cfg.xml file, you need to specify the cache provider class, cache region prefix, and cache configuration properties such as the cache mode, cache provider, and cache region.