The
standard programming language used for interacting with a database structure is
known as the structured query language (SQL). It is considered the standard for
both ANSI (American National Standards Institute) and ISO (International
Standard Organization) meaning it is used worldwide for all databases [1].
In the
late 1970s, the premise for SQL was developed using relational models as its
basis. In 1979, Relational Software, Inc. it was introduced as the first
commercially available application of SQL. In 1987 it was established as the worldwide
standard and has remained such since then. Over time it has been continually
revised to include various amounts of additional features.
Since
its creation, SQL has adapted in several substantial ways from its foundation
of relational models and tuple calculus. In the older (theoretical) model, a
table was treated as a set of tuples. In the revised version of SQL, tables and
query results are considered lists of rows. Rows can occur multiple times, and
the order of any row can be employed in queries (the basis if the programming
language).
One
limitation with the language is that one set of code may not be entirely
transferrable from one database to another without some sort of adjustment.
Despite this it has a number of benefits which make it useful in managing
databases. Most operations in SQL are handled through the use of programming
elements. One such element is queries.
Queries are one of the core
applications of SQL and allow the user to do a number of operations within the
database. These includes things such as selecting, inserting, updating, and
finding the location of data. It also includes a programming interface for the
user [2].
Other elements of SQL include
clauses, expressions, predicates, and statements. Clauses are constituent
components of statements and queries. Expressions are used to produce either
scalar values or tables made of columns and rows of data. Predicates are used
to specify conditions which can then be evaluated in SQL. These can be used to
limit the effects of statements and queries and effect the program flow.
What makes SQL so important is that
it is established as the standard for all programming language within a
database, thus being the prominent way to interact with one. Knowing how to
best implement this language is fundamental for any sort of database
management, an important skill to have in a world driven by data.
Sources:
Comments:
Kai,
ReplyDeleteI like how you delved into the history of how SQL was invented and for the initial purposes for which it was invented. I also enjoyed learning about the different components that make up SQL such as clauses, expressions, and predicates. It is important to learn about these factors in order to fully understand the purpose of SQL and its importance in relation to databases.
This was an interesting read as it tied into my topic for this week, which was the relational database theory that used SQL to program. I wasn't too sure about what SQL is but you have cleared that up with this blog post.
ReplyDeleteI agree that SQL is important because it is generally the way in which a user interacts with a database. Data is very important and present in today's world, from databases of information about products to the database that holds all of the information of this blog. Having a unified (or at least mostly unified) language behind accessing this information is very important for interoperability and information exchange between databases.
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