Posts (page 116)
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6 min readWhen using Hibernate, you can avoid updating child tables when using the save method by making sure that the child entities are not attached to the session when saving the parent entity. One way to achieve this is by using the transient keyword in the mapping of the child entities. This tells Hibernate not to track the changes made to the child entities.Another way to prevent updating child tables is by setting the cascade type to NONE or PERSIST in the parent entity's mapping.
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5 min readTo use "like" in Oracle with PHP, you can incorporate the "LIKE" keyword in your SQL query when selecting or updating data from a database using PHP. This can be useful for searching for data that matches a specific pattern or contains a particular substring.
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9 min readTo optimize a Hibernate query, you can follow several best practices.First, make sure to use proper indexing on the database tables that are involved in the query. This can significantly improve the query performance by allowing the database to quickly locate the relevant data.Additionally, consider prefetching associations using the fetch keyword in your HQL or Criteria queries. This can reduce the number of queries needed to retrieve the data, improving performance.
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3 min readTo parse JSON efficiently in Oracle 18c, you can use the JSON functions available in the database. You can use functions such as JSON_VALUE, JSON_QUERY, and JSON_TABLE to extract specific values or elements from a JSON document.JSON_VALUE function is used to extract a scalar value from a JSON document. JSON_QUERY function is used to extract a JSON object or array from a JSON document. JSON_TABLE function is used to extract data from a JSON document and provide it in a tabular format.
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7 min readTo persist a list of objects as a JSONB field in Hibernate, you can use the @Type annotation provided by Hibernate. By annotating the field with @Type, you can specify that the field should be mapped to a JSONB column in the database. Additionally, you can customize the serialization and deserialization of the JSON data by providing a custom UserType implementation.
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5 min readTo select data from Oracle using PHP, you will need to establish a connection to the Oracle database using the appropriate credentials. You can use the OCI8 extension in PHP to connect to Oracle databases.Once you have successfully connected to the Oracle database, you can use SQL queries to retrieve data from the tables. You can use the oci_parse() function to prepare a SQL query, and then execute the query using the oci_execute() function.
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7 min readTo delete multiple records using REST API in Hibernate, you will first need to create a custom endpoint in your REST API that handles the deletion request.In this endpoint, you can receive a list of IDs or any other identifiers that you want to delete from the database. Then, you can use Hibernate's Session object or a repository interface to manually delete each record based on the provided identifiers.
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4 min readTo get the name of the caller object in Oracle, you can use the SYS_CONTEXT function in conjunction with the USER or CLIENT_IDENTIFIER parameters.
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7 min readIn Hibernate, pg_column_size is a native PostgreSQL function that allows you to retrieve the size of a column in bytes. To use pg_column_size in Hibernate, you can write a native SQL query in your Hibernate code and use the pg_column_size function to get the size of a specific column.For example, you can write a native SQL query in your Hibernate repository class like this: String sql = "SELECT pg_column_size(column_name) FROM table_name WHERE condition"; Query query = entityManager.
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5 min readTo rename a column with grouping sets in Oracle, you can use the AS keyword followed by the new column name after the original column name in the SELECT statement. This will rename the column in the result set that is generated by the grouping sets. Make sure to enclose the new column name in double quotes if it contains special characters or spaces. Additionally, you can also use column aliases to rename columns in the result set.
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5 min readTo return all values in JPA and Hibernate, you can use the findAll() method provided by the JpaRepository interface in Spring Data JPA. This method retrieves all entities of a given type from the database.In Hibernate, you can use criteria queries or HQL (Hibernate Query Language) to fetch all records from a database table. Criteria queries allow you to specify certain conditions and restrictions on the returned entities, while HQL provides a more SQL-like syntax for querying entities.
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4 min readTo convert a vertical string into horizontal in Oracle, you can use the LISTAGG function along with the GROUP BY clause.