Home >> Science & Nature >> Science

Why Is a Sequence Used in SQL?

Structured Query Language (SQL) is a powerful tool for communicating with established databases within a computer system. Sequences are used in SQL to chain together a series of commands in order to pull up a particular set of data types. According to SQL.org, the CREATE SEQUENCE command is used to start a new sequence. Stanford University points out another use of SQL sequences: to define user sessions and prevent one user's actions in the database from overwriting another user's. The University of Maryland at Baltimore County adds that sequences are commonly found in complex database applications.

Database Applications
- Digital technology has made it difficult to manage and store the vast quantities of data that are generated by computing processes. A systematic means of locating data in a system and relating it to other data points and types is ideal for obtaining an organized, accessible information system. The database was created to fill this need, and scripting languages like SQL were developed to handle placing information in the database and pulling information out of it in a predictable manner.
SQL as a Database Tool
- SQL is a flexible and adaptable language that can be used to enter data into a system and then retrieve it. SQL operates by stringing together specific commands that are associated with a particular operation. The database that is the target of the commands is defined in the SQL string, as well as the class of data within it to be accessed. SQL statements can be strung together to perform a number of powerful tasks.
SQL Sequences
- A sequence in SQL involves a set group of operations, providing a handy, rapid means of grabbing a particular set of data defined by specific characteristics from the database. SQL sequences can be used to establish predefined call or entry operations that present a predictable set of data to a user who may not be familiar with the intricacies of SQL. Sequences can also be strung together as part of an even larger structure to sort and manage data.
SQL and User Sessions
- One of the biggest problems in a database is how to manage multiple users simultaneously performing operations within the database. Major databases used by government and corporate offices often need to be simultaneously accessed and modified by multiple users. Ensuring that one user's changes are not overwritten as they are being made can be accomplished by assigning each distinct user a session ID that records changes to a record and does not allow simultaneous editing. SQL sequences can be set up to assign this ID and then record the changes made, making it easy to determine who has made changes to data and what changes have been made.

Science