Fiszki: SQL | Quizlet

ASC keyword

ASC keyword

Used to sort data in ascending order.

Data type

Specifies the type of data that a column can hold (e.g., text and numbers).

DESC keyword

Used to sort data in descending order

ORDER BY clause

Retrieves the name of one or more columns from the SELECT statement, and sorts (ascending or descending) the output.

Client

A single-user computer that interfaces with the multiple-user server.

Client/server database system

A system that divides processing between client computers and a database server.

Database

A collection of electronically stored organized files.

Server

A multiple-user computer that provides shared database connection, interfacing, and processing services.

Field

Column that runs vertically within a table.

Foreign key

Link records of one type with those of another type.

Keys

Uniquely identify a row or record in a table.

Normalization

A three-step technique used to organize data attributes in a more efficient, reliable, flexible, and maintainable structure.

Pprimary key

A field whose value uniquely identifies every row in a table.

Row

A record that represents a collection of information relating to an item in a table.

Table

Structured file containing rows and columns.

SQL Defined

SQL is a nonprocedural language that is used to manipulate and retrieve data from relational DBMSs such as Microsoft Access, DB2, Sybase, and Microsoft SQL Server. It is considered nonprocedural because of the way operations are carried out. Unlike procedural computer languages like Basic and C, which are concerned with how to perform operations, SQL describes what needs to be processed. The focus is on what to retrieve, delete, or insert.

Query

A question or command you pose concerning data from the database.

Parts of a query include the following:
Clause

A segment of an SQL statement combined to form a complete SQL statement.

Parts of a query include the following:
Keywords

Reserved words that allow you to communicate with a database.

Parts of a query include the following:
Statement

Keywords and data supplied within an SQL query.

Keywords:
FROM keyword

Used to tell the database which table to retrieve the columns from.

Keywords:
SELECT keyword

Used to tell the database which column(s) to display.

Syntax Rules

Syntax refers to the rules that govern how a programming language must be written.

Comparison Operators

Comparison Operators

The comparison operators are used to compare expressions. An expression is any data type that returns a value

Arithmetic Operators

Plus (+)
Minus (-)
Divide (/)
Modulus (%)
Multiply (*)

Sorting Data Using the WHERE Clause

The ability to sort data further enhances the data-retrieval process. Sorting data involves filtering and arranging retrieved data in a customized fashion. In SQL, this is achieved by using the following clauses:
GROUP BY
HAVING
ORDER BY
STARTING WITH
WHERE

Asterisk wildcard character (*)

When used with the LIKE operator, you can match any number of occurrences of any character.

Brackets wildcard character ( [] )

When used with the LIKE operator, you can specify a set of characters that match a character in a specific position.

LIKE operator

A character operator. When used in conjunction with asterisks or brackets, matches parts of a value within a table.

IN operator

A miscellaneous operator that provides a shorter method for specifying a range of conditions.

NOT operator

A logical operator used to match any condition opposite of the one defined.