Glossary

Active Server Pages (ASP)

A Microsoft server-side technology for accepting client Web input, manipulating databases, and returning data results to the client.

aggregate function

A SQL function that returns a single value after performing a column calculation on a rowset in SQL.

alias

An alternative name for a table or column in expressions, an alias often used to shorten the name for subsequent reference in code, to prevent possible ambiguous references, or to provide a more descriptive name in the query output. An alias also can be an alternative name for a server.

ancestor

In XPath, a previous node in a hierarchy that is related through lineage to the current node.

See also [ child, parent, descendant, sibling. ]

attribute

A data item that provides additional data about its parent element.

axis

In XML, it specifies the tree relationship between the nodes selected by the location step and the context node.

binary large object

A large file, typically an image or sound file, that must be handled (for example, uploaded, downloaded, or stored in a database) in a special way because of its size .

BLOB

See [ binary large object. ]

Boolean

An operation or expression that can be evaluated only as either true or false.

business rules

The logical rules used to run a business. Business rules can be enforced in a SQL Server database using triggers, stored procedures, and constraints. Usually expressed with conditional logic, such as:

 if CreditCard = Amex then      GiveDiscount() 

calculated column

A column in a table that displays the result of an expression rather than stored data for example:

 CalcCost = Price * Quantity 

CDATA

An XML document section that defines literal data that will not be interpreted or changed in any way.

character set

A character set determines the types of characters that SQL Server recognizes in the char , varchar , and text data types. Each character set is a set of 256 letters , digits, and symbols specific to a country or language. The printable characters of the first 128 values are the same for all character sets. The last 128 characters, sometimes referred to as extended characters, are unique to each character set. A character set is related to, but separate from, Unicode characters.

child

In XPath, a node of the immediately subsequent level in a hierarchy that is directly related to the current node.

See also [ ancestor, parent, descendant, sibling. ]

concatenation

Combining two or more character or binary strings or expressions into a single character or binary string or expression. For example,

 Name = "John" + "Griffin". 

context node

The current node or the node being tested by an XPath expression.

data type

An attribute that specifies what type of information can be stored in a column, parameter, node, or variable. Examples include string and integer.

database

A collection of information, tables, and other objects organized and presented to serve a specific purpose, such as searching, sorting, and recom-bining data. Databases are usually stored in files.

descendant

In XPath, a node in a hierarchy that is related to a node of a preceding level within the same hierarchy.

See also [ ancestor, child, parent, sibling. ]

double-byte character set (dbcs)

A character set that generally uses two bytes to represent a character, allowing more than 256 characters to be represented.

element

A logical unit within an XML document delimited by start and end tags.

expression

A combination of symbols, data, and operators that evaluates to a single data valuefor example,

 a + b = c. 

float data type

A data type that holds floating-point number data from 1.79E + 308 through 1.79E + 308 in SQL Server.

hierarchy

A logical tree structure that organizes its nodes so that each node has one parent node and zero or more child nodes.

HTML

See [ Hypertext Markup Language (HTML). ]

HTTP

See [ Hypertext Transfer Protocol (HTTP). ]

Hypertext Markup Language (HTML)

A system of marking up, or tagging, a document so that it can be published on the World Wide Web. Documents prepared in HTML include reference graphics and formatting tags. A Web browser is used to view these documents.

Hypertext Transfer Protocol (HTTP)

A set of rules for exchanging files (text, graphic images, sound, video, and other multimedia files) on the World Wide Web. Relative to the TCP/IP suite of protocols (which are the basis for information exchange on the Internet), HTTP is an application protocol.

ID

In XML, an attribute of type ID has a unique value within a document.

IEC

See [ International Electrotechnical Commission (IEC). ]

image data type

A SQL Server variable-length binary data type with a maximum length of 2^31 1 (which equals 2,147,483,647) bytes.

int (integer) data type

In SQL Server 2000, this data type category includes the bigint , int , smallint , and tinyint data types.

International Organization for Standardization (ISO)

One of two international standards bodies responsible for developing international data communications standards. The ISO works closely with the International Electrotechnical Commission (IEC) to define standards for computing. They jointly published the ISO/IEC SQL-92 standard for SQL.

International Electrotechnical Commission (IEC)

One of two international standards bodies responsible for developing international data communications standards. The IEC works closely with the ISO to define standards for computing. They jointly published the ISO/IEC SQL-92 standard for SQL.

ISO

See [ International Organization for Standardization (ISO). ]

ISO-10646

ISO/IEC 10646-1:1993 (published in the first or second quarter of 2000) defines one repertoire of characters and two encoding forms, UCS-4 and UCS-2. The UCS-2 encoding form is related to the UCS-4 encoding form by zero extension; that is, by zero extending the 16-bit form to 32 bits, the equivalent UCS-4 encoding form is created.

literal result element

An element in a template body that is not an XSLT instruction or extension element.

local variable

A variable defined within a template body.

location step

In XPath, this selects a set of nodes relative to a context node.

logical operators

The operators AND , OR , and NOT .

metadata

Information about the properties of data, such as the type of data in a column (numeric, text, and so on) or the length of a column.

N

Causes a string value to be inserted into a database as a Unicode string or a Unicode value to be assigned to a variable. For example,

 @Name = N'John'. 

'John' is converted to a UNICODE string and assigned to Name.

See also [ Unicode strings. ]

namespace

In XML, a named collection of names . Guarantees that an element name is unique in a collection of documents.

namespace declaration

An XML document construct that defines a prefix used within a part of the document to refer to a namespace with a certain URI.

NCName

A simple name specified to be used in various places of the XML specification.

node

In XML, any object within an XML tree.

node set

A collection of nodes from one or more XML documents.

NULL

An entity that has no explicitly assigned value. NULL is not equivalent to zero or blank. (NULL doesn't equal NULL or any other quantity).

parent

In XML, a node in the immediately preceding level in a hierarchy that is directly related to the current node.

See also [ ancestor, child, descendant, sibling. ]

parent column

The second column of the Universal table. It indicates the parent tag for the present element.

pattern

An XPath construct that defines a condition met by a node set.

predicate

Part of an XPath expression that selects a subset of a node set.

QName

In XML, a qualified name that is either a simple name (NCName) or a name preceded by a namespace and a colon .

query optimizer

The SQL Server database engine component responsible for generating efficient execution plans for SQL statements. Used exclusively by the SQL Server system.

real data type

A SQL Server system data type that has seven-digit precision. Floating-precision number data from 3.40E + 38 through 3.40E + 38.

record

A group of related columns of information treated as a unit in a SQL table. A record is more commonly called a row.

recursion

A recursive procedure or routine is one that has the capability to call itself. A recursive expression is a function, algorithm, or sequence of instructions (typically, an IF-THEN-ELSE sequence) that loops back to the beginning of itself until it detects that some condition has been satisfied.

result set

The set of rows returned from a SQL SELECT statement. The format of the rows in the result set is defined by the column list of the SELECT statement.

root node

The topmost node in an XML tree.

row

The collection of elements that form a horizontal line in a table. Each row in the table represents a single occurrence of the object modeled by the table and stores the all the object's attribute values.

SGML

See [ Standard Generalized Markup Language (SGML). ]

shredding

The process of breaking up an XML document so that its data can be put into database tables.

sibling

A node in a hierarchy that is a child of the same parent as a specified node.

See also [ ancestor, child, descendant, parent. ]

SQL

See [ structured query language (SQL). ]

SQL expression

Any combination of operators, constants, literal values, functions, and names of tables and fields that evaluates to a single value.

SQL statement

A SQL or TransactSQL command, such as SELECT or DELETE, that performs some action on data in a relational database.

Standard Generalized Markup Language (SGML)

A standard for how to specify a document markup language or tag set. Such a specification is itself a document type definition. SGML is not in itself a document language but a description of how to specify one.

stored procedure

A precompiled collection of SQL statements stored under a name and processed as a unit.

string

A set of bytes that contain a single character-based or binary data value. In character strings, each byte (or pair of bytes) represents a single alphabetic letter, special character, or number.

string functions

Functions that perform operations on character or binary strings. For example, LEN(name) returns the number of characters in the variable name .

structured query language (SQL)

A language used to insert, retrieve, modify, and delete data in a relational database. It also contains statements for defining and administering a database.

table

A two-dimensional object, consisting of rows and columns, used to store data in a relational database.

tag column

The first column of a Universal table. It indicates the level of an element in an XML document, with NULL being the top-level element.

text node

An XML node represented by character data.

top-level element

Elements positioned between the

 <xsl:stylesheet> 

element and the root element of the XML document. They perform a variety of functions.

tree

The information content of an XML document in an abstract form. Used by XPath for queries.

trigger

A stored procedure that executes when data in a specific table is modified. A trigger is created like this:

 CREATE TRIGGER trig1 ON table1 AS 

UCS

See [ Universal Coded Character Set ]

Unicode strings

Unicode strings have a format similar to character strings, but they are preceded by an N identifier (N stands for National Language in the SQL-92 standard).The N prefix must be uppercase. For example, 'Miche[as]l' is a character constant whereas N'Miche[as]l' is a Unicode constant. Unicode constants are interpreted as Unicode data and are not evaluated using a code page. Unicode data is stored using 2 bytes per character, as opposed to 1 byte per character for character data.

uniform resource identifier (URI)

The way you identify points of content on the Internet, whether it's a page of text, a video or sound clip, a still or animated image, or a program. The most common form of URI is the Web page address, which is a particular form or subset of URI called a uniform resource locator (URL). For example,

http://www.w3c.org . See RFC 1630 and

http://www.w3.org/Addressing/#terms .

uniform resource locator (URL)

Uniform resource identifier used to locate pages on the World Wide Web. For example,

http://www.microsoft.com. See

http://www.w3.org/Addressing/#terms.

Universal Coded Character Set

A code set containing all characters commonly used in computer applications anywhere in the world. The initial version of 10646 contains approximately 33,000 characters covering a long list of languages including European, Asian ideographic, Middle Eastern, Indian, and others. It also reserves 6,000 code spaces for private use.

Universal Coded Character Set Transformation Format (UTF)

UTF-8 is standard ASCII.

See also [ Universal Coded Character Set. ]

Universal table

Used by the FOR XML statement in EXPLICIT mode. It defines the rowset layout of data used to generate an XML document.

URI

See [ uniform resource identifier (URI). ]

URL

See [ uniform resource locator (URL). ]

UTF

See [ Universal Coded Character Set Transformation Format. ]

varchar data type

A data type that holds variable-length non-Unicode data with a maximum of 8,000 characters. Size might differ in other relational database management systems (RDBMS).

view

A database object that can be referenced the same way as a table in SQL statements.Views are defined using a SELECT statement.

W3C

The World Wide Web Consortium, an Internet standards organization located at http://www.w3c.org.

XML

Extensible Markup Language. XML is a flexible way to create common information formats and share both the format and the data on the World Wide Web, intranets , and elsewhere.

XPath

A language that describes a way to locate and process items in Extensible Markup Language ( XML ) documents by using an addressing syntax based on a path through the document's logical structure or hierarchy.

XSLT (Extensible Stylesheet Language Transformations)

XSLT is a standard way to describe how to transform (change) the structure of an XML document into an XML document with a different structure or an HTML document. XSLT is a recommendation of the World Wide Web Consortium ( W3C ).