Liquibase

Last updated
Liquibase
Developer(s) Nathan Voxland
Stable release
4.25.0 / November 13, 2023;5 months ago (2023-11-13) [1]
Repository github.com/liquibase/liquibase
Written in Java
Operating system Cross-platform
Type Software development
License Apache License 2.0, Freemium
Website www.liquibase.org

Liquibase is an open-source database-independent library for tracking, managing and applying database schema changes. It was started in 2006 to allow easier tracking of database changes, especially in an agile software development environment.

Contents

Overview

All changes to the database are stored in text files (XML, YAML, JSON or SQL) and identified by a combination of an "id" and "author" tag as well as the name of the file itself. A list of all applied changes is stored in each database which is consulted on all database updates to determine what new changes need to be applied. As a result, there is no database version number but this approach allows it to work in environments with multiple developers and code branches.

Liquibase automatically creates DatabaseChangeLog Table and DatabaseChangeLogLock Table when you first execute a changeLog File.

Major functionality


The following is a list of major features:

Commercial version

Liquibase (formerly Datical) [2] is both the largest contributor to the Liquibase project and the developer of Liquibase Enterprise [3] – a commercial product which provides the core Liquibase functionality plus additional features.

Liquibase products, including Liquibase Enterprise (formerly known as Datical DB), are used by DBAs, Release Managers, DevOps teams, Application Owners, Architects, and Developers involved in the Application Release process. It manages Database Schema changes together with application code in a programmatic fashion that eliminates errors and delays and enables rapid Agile releases. Liquibase commercial products build upon the Liquibase Data Model Approach for managing data structure specific content across application versions as they advance from Development to Test to Production environments. Datical previews the impact of Schema changes in any environment before deployment thus mitigating risk and resulting in smoother and faster application changes.

Liquibase developer, Nathan Voxland, is an executive at Liquibase (formerly Datical). [7]

Sample Liquibase changelog file

<?xml version="1.0" encoding="UTF-8"?><databaseChangeLogxmlns="http://www.liquibase.org/xml/ns/dbchangelog/1.3"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog/1.3        http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-1.3.xsd"><preConditions><dbmstype="oracle"/></preConditions><changeSetid="1"author="author1"><createTabletableName="persons"><columnname="id"type="int"autoIncrement="true"><constraintsprimaryKey="true"nullable="false"/></column><columnname="name"type="varchar(50)"/></createTable></changeSet><changeSetid="2"author="author2"context="test"><inserttableName="persons"><columnname="id"value="1"/><columnname="name"value="Test1"/></insert><inserttableName="persons"><columnname="id"value="2"/><columnname="name"value="Test2"/></insert></changeSet></databaseChangeLog>

Related Research Articles

<span class="mw-page-title-main">Database</span> Organized collection of data in computing

In computing, a database is an organized collection of data or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, applications, and the database itself to capture and analyze the data. The DBMS additionally encompasses the core facilities provided to administer the database. The sum total of the database, the DBMS and the associated applications can be referred to as a database system. Often the term "database" is also used loosely to refer to any of the DBMS, the database system or an application associated with the database.

A relational database (RDB) is a database based on the relational model of data, as proposed by E. F. Codd in 1970. A database management system used to maintain relational databases is a relational database management system (RDBMS). Many relational database systems are equipped with the option of using SQL for querying and updating the database.

Transact-SQL (T-SQL) is Microsoft's and Sybase's proprietary extension to the SQL used to interact with relational databases. T-SQL expands on the SQL standard to include procedural programming, local variables, various support functions for string processing, date processing, mathematics, etc. and changes to the DELETE and UPDATE statements.

A temporal database stores data relating to time instances. It offers temporal data types and stores information relating to past, present and future time. Temporal databases can be uni-temporal, bi-temporal or tri-temporal.

A database trigger is procedural code that is automatically executed in response to certain events on a particular table or view in a database. The trigger is mostly used for maintaining the integrity of the information on the database. For example, when a new record is added to the employees table, new records should also be created in the tables of the taxes, vacations and salaries. Triggers can also be used to log historical data, for example to keep track of employees' previous salaries.

An XML database is a data persistence software system that allows data to be specified, and sometimes stored, in XML format. This data can be queried, transformed, exported and returned to a calling system. XML databases are a flavor of document-oriented databases which are in turn a category of NoSQL database.

In a database, a view is the result set of a stored query, which can be queried in the same manner as a persistent database collection object. This pre-established query command is kept in the data dictionary. Unlike ordinary base tables in a relational database, a view does not form part of the physical schema: as a result set, it is a virtual table computed or collated dynamically from data in the database when access to that view is requested. Changes applied to the data in a relevant underlying table are reflected in the data shown in subsequent invocations of the view.

Object–relational impedance mismatch is a set of difficulties going between data in relational data stores and data in domain-driven object models. Relational Database Management Systems (RDBMS) is the standard method for storing data in a dedicated database, while object-oriented (OO) programming is the default method for business-centric design in programming languages. The problem lies in neither relational databases nor OO programming, but in the conceptual difficulty mapping between the two logic models. Both logical models are differently implementable using database servers, programming languages, design patterns, or other technologies. Issues range from application to enterprise scale, whenever stored relational data is used in domain-driven object models, and vice versa. Object-oriented data stores can trade this problem for other implementation difficulties.

In computer science, a database cursor is a mechanism that enables traversal over the records in a database. Cursors facilitate subsequent processing in conjunction with the traversal, such as retrieval, addition and removal of database records. The database cursor characteristic of traversal makes cursors akin to the programming language concept of iterator.

<span class="mw-page-title-main">Virtuoso Universal Server</span> Computer software

Virtuoso Universal Server is a middleware and database engine hybrid that combines the functionality of a traditional relational database management system (RDBMS), object–relational database (ORDBMS), virtual database, RDF, XML, free-text, web application server and file server functionality in a single system. Rather than have dedicated servers for each of the aforementioned functionality realms, Virtuoso is a "universal server"; it enables a single multithreaded server process that implements multiple protocols. The free and open source edition of Virtuoso Universal Server is also known as OpenLink Virtuoso. The software has been developed by OpenLink Software with Kingsley Uyi Idehen and Orri Erling as the chief software architects.

An entity–attribute–value model (EAV) is a data model optimized for the space-efficient storage of sparse—or ad-hoc—property or data values, intended for situations where runtime usage patterns are arbitrary, subject to user variation, or otherwise unforeseeable using a fixed design. The use-case targets applications which offer a large or rich system of defined property types, which are in turn appropriate to a wide set of entities, but where typically only a small, specific selection of these are instantiated for a given entity. Therefore, this type of data model relates to the mathematical notion of a sparse matrix. EAV is also known as object–attribute–value model, vertical database model, and open schema.

Oracle Data Mining (ODM) is an option of Oracle Database Enterprise Edition. It contains several data mining and data analysis algorithms for classification, prediction, regression, associations, feature selection, anomaly detection, feature extraction, and specialized analytics. It provides means for the creation, management and operational deployment of data mining models inside the database environment.

Microsoft SQL Server is a proprietary relational database management system developed by Microsoft. As a database server, it is a software product with the primary function of storing and retrieving data as requested by other software applications—which may run either on the same computer or on another computer across a network. Microsoft markets at least a dozen different editions of Microsoft SQL Server, aimed at different audiences and for workloads ranging from small single-machine applications to large Internet-facing applications with many concurrent users.

Apache Click is a page and component oriented web application framework for the Java language and is built on top of the Java Servlet API.

Apache Empire-db is a Java library that provides a high level object-oriented API for accessing relational database management systems (RDBMS) through JDBC. Apache Empire-db is open source and provided under the Apache License 2.0 from the Apache Software Foundation.

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 and update data in a database, and is oriented toward relational databases. A JDBC-to-ODBC bridge enables connections to any ODBC-accessible data source in the Java virtual machine (JVM) host environment.

In computing, Open Data Protocol (OData) is an open protocol that allows the creation and consumption of queryable and interoperable Web service APIs in a standard way. Microsoft initiated OData in 2007. Versions 1.0, 2.0, and 3.0 are released under the Microsoft Open Specification Promise. Version 4.0 was standardized at OASIS, with a release in March 2014. In April 2015 OASIS submitted OData v4 and OData JSON Format v4 to ISO/IEC JTC 1 for approval as an international standard. In December 2016, ISO/IEC published OData 4.0 Core as ISO/IEC 20802-1:2016 and the OData JSON Format as ISO/IEC 20802-2:2016.

In database management systems (DBMS), a prepared statement, parameterized statement, or parameterized query is a feature where the database pre-compiles SQL code and stores the results, separating it from data. Benefits of prepared statements are:

PL/SQL is Oracle Corporation's procedural extension for SQL and the Oracle relational database. PL/SQL is available in Oracle Database, Times Ten in-memory database, and IBM Db2. Oracle Corporation usually extends PL/SQL functionality with each successive release of the Oracle Database.

The following is provided as an overview of and topical guide to databases:

References

  1. ↑ "Liquibase Downloads". liquibase.com. Liquibase. Retrieved 2023-12-06.
  2. ↑ "Datical is Now Liquibase; Company Returns to its Open Source Roots with Support from its Community". 19 May 2020.
  3. ↑ "Liquibase Enterprise". Liquibase. Retrieved 2020-05-29.
  4. ↑ "Database Forecast Tools for Change Management".
  5. ↑ "Liquibase Rules". Liquibase. Retrieved 2020-05-29.
  6. ↑ "Our partners". Liquibase. Retrieved 2020-05-29.
  7. ↑ "Liquibase Leadership". Liquibase. Retrieved 2020-05-29.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.