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History. SQL was initially developed at IBM by Donald D. Chamberlin and Raymond F. Boyce after learning about the relational model from Edgar F. Codd in the early 1970s. This version, initially called SEQUEL (Structured English Query Language), was designed to manipulate and retrieve data stored in IBM's original quasirelational database management system, System R, which a group at IBM San ...
In database systems, atomicity ( / ˌætəˈmɪsəti /; from Ancient Greek: ἄτομος, romanized : átomos, lit. 'undividable') is one of the ACID ( Atomicity, Consistency, Isolation, Durability) transaction properties. An atomic transaction is an indivisible and irreducible series of database operations such that either all occur, or none ...
Rollback (data management) In database technologies, a rollback is an operation which returns the database to some previous state. Rollbacks are important for database integrity, because they mean that the database can be restored to a clean copy even after erroneous operations are performed. [1] They are crucial for recovering from database ...
Web SQL Database is a deprecated web browser API specification for storing data in databases that can be queried using SQL variant. [1] [2] The technology was only ever implemented in Blink-based browsers like Google Chrome and the new Microsoft Edge, and WebKit-based browsers like Safari. As of February 2024, WebSQL is being phased out in ...
Join (SQL) A Venn diagram representing the full join SQL statement between tables A and B. A join clause in the Structured Query Language ( SQL) combines columns from one or more tables into a new table. The operation corresponds to a join operation in relational algebra. Informally, a join stitches two tables and puts on the same row records ...
Database normalization. Database normalization is the process of structuring a relational database in accordance with a series of so-called normal forms in order to reduce data redundancy and improve data integrity. It was first proposed by British computer scientist Edgar F. Codd as part of his relational model .
Prepared statement. 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: [1] efficiency, because they can be used repeatedly without re-compiling.
Delete (SQL) In the database structured query language ( SQL ), the DELETE statement is used to remove one or more records from a table. A subset may be defined for deletion using a condition, otherwise all records are removed. [1] Some database management systems (DBMSs), like MySQL, allow deletion of rows from multiple tables with one DELETE ...