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The active record pattern is an approach to accessing data in a database. A database table or view is wrapped into a class. Thus, an object instance is tied to a single row in the table. After creation of an object, a new row is added to the table upon save. Any object loaded gets its information from the database.
Java Database Connectivity (JDBC) is an application programming interface (API) for the Java programming language which defines how a client may access a database. It is a Java-based data access technology used for Java database connectivity. It is part of the Java Standard Edition platform, from Oracle Corporation. It provides methods to query ...
The introduction section of the JPA specification states: "The technical objective of this work is to provide an object/relational mapping facility for the Java application developer using a Java domain model to manage a relational database." [5] The Java Data Objects specification supports ORM as well as persistence to other types of database ...
In some databases, such as PostgreSQL, when a FROM clause is present, what essentially happens is that the target table is joined to the tables mentioned in the fromlist, and each output row of the join represents an update operation for the target table. When using FROM, one should ensure that the join produces at most one output row for each ...
Some database implementations adopted the term upsert (a portmanteau of update and insert) to a database statement, or combination of statements, that inserts a record to a table in a database if the record does not exist or, if the record already exists, updates the existing record. This synonym is used in PostgreSQL (v9.5+) [2] and SQLite (v3 ...
In software, a data access object (DAO) is a pattern that provides an abstract interface to some type of database or other persistence mechanism. By mapping application calls to the persistence layer, the DAO provides data operations without exposing database details. This isolation supports the single responsibility principle.
If the data is being persisted in a modern database then Change Data Capture is a simple matter of permissions. Two techniques are in common use: Tracking changes using database triggers; Reading the transaction log as, or shortly after, it is written. If the data is not in a modern database, CDC becomes a programming challenge.
The Jakarta Persistence Query Language (JPQL; formerly Java Persistence Query Language) is a platform-independent object-oriented query language [1]: 284, §12 defined as part of the Jakarta Persistence (JPA; formerly Java Persistence API) specification. JPQL is used to make queries against entities stored in a relational database.