Posts - Page 119 (page 119)
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7 min readTo populate two fields of an entity using Hibernate, you can create an instance of the entity class and set the values for the fields that you want to populate. Then, use Hibernate's session object to save the entity to the database. You can access the session object by calling the getSession() method on the Hibernate SessionFactory object.Once you have retrieved the session object, you can begin a transaction by calling the beginTransaction() method on the session object.
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6 min readTo convert exponent values in numbers in Oracle, you can use the TO_NUMBER function. This function allows you to convert a string representation of a number with an exponent (scientific notation) into a regular number format. For example, if you have a column with exponent values like '1.23E+2', you can convert it to a regular number format by using the TO_NUMBER function like this: SELECT TO_NUMBER('1.23E+2') FROM dual; This will return the value 123.
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4 min readTo join 3 tables using Hibernate Criteria, you can use createAlias() method multiple times to specify the associations between entities. By creating aliases for each association, you can navigate through the relationships and fetch the desired records.For example, if you have three entities A, B, and C with associations between A and B, and B and C, you can join all three tables using Hibernate Criteria as follows:Criteria criteria = session.createCriteria(A.class); criteria.
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5 min readTo convert a time string in UTC to CST in Oracle, you can use the function TO_TIMESTAMP_TZ to convert the time string to a timestamp with time zone in UTC. Then, you can use the function FROM_TZ to convert the timestamp to the desired time zone, in this case CST (Central Standard Time).
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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.