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Beautiful Soup was started in 2004 by Leonard Richardson. [citation needed] It takes its name from the poem Beautiful Soup from Alice's Adventures in Wonderland [5] and is a reference to the term "tag soup" meaning poorly-structured HTML code. [6]
Relation, tuple, and attribute represented as table, row, and column respectively. In database theory, a relation, as originally defined by E. F. Codd, [1] is a set of tuples (d 1,d 2,...,d n), where each element d j is a member of D j, a data domain. Codd's original definition notwithstanding, and contrary to the usual definition in ...
The Suppliers and Parts database is an example relational database that is referred to extensively in the literature [citation needed] and described in detail in C. J. Date's An Introduction to Database Systems, 8th ed. [1] It is a simple database comprising three tables: Supplier, Part and Shipment, and is often used as a minimal exemplar of the interrelationships found in a database.
Relics of this can be found today in the glob syntax for filenames, and in the SQL LIKE operator. Starting in 1997, Philip Hazel developed PCRE (Perl Compatible Regular Expressions), which attempts to closely mimic Perl's regex functionality and is used by many modern tools including PHP and Apache HTTP Server .
Visual representation often may also be exported as a production-ready source code made in DB-compatible languages like SQL. The database schema is the structure of a database described in a formal language supported typically by a relational database management system (RDBMS).
Attributes in ER diagrams are usually modeled as an oval with the name of the attribute, linked to the entity or relationship that contains the attribute. ER models are commonly used in information system design; for example, they are used to describe information requirements and / or the types of information to be stored in the database during ...
A table (called the referencing table) can refer to a column (or a group of columns) in another table (the referenced table) by using a foreign key.The referenced column(s) in the referenced table must be under a unique constraint, such as a primary key.
SQL was initially developed at IBM by Donald D. Chamberlin and Raymond F. Boyce after learning about the relational model from Edgar F. Codd [12] in the early 1970s. [13] 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 ...