SQL/Oracle SQL Flashcards
allow us to select only the row in the result relation of the from clause that satisfy a specified predicaments
where clause
renaming the attributes of a result relation
Old-name as new name
matches any string with at least three characters
%
matches any string beginning with “Intro”
Intro%
matches any string containing “Comp” as a substring
%Comp%
for specifying access right to the relations and views
Authorization
A integer. A finite subset of the integer that is machined dependent
int
for specifying the beginner and end point of transaction
Transaction control
Has change to SQL
Sequel
The American National Standards Institute (ANSI) and the International Organization for Standardization published an SQL standard called SQL-86
1986
define how SQL statement can be embedded within general purpose programming language such as C, C++ and Java
Embedded SQL and Dynamic SQL
a fixed-length character string user specified length n
char(n)
for specifying integrity constraints that the data stored in the database must satisfy
Integrity
matches any substring
Percent
A small integer. The machine dependent subset of the integer type
smallint
provide the ability to query information from the database to insert tuples into, delete tuples from and modify tuples in the database
Data Manipulation Language (DML)
matches any characters
Underscore
a floating point number with precision of at least n digits.
float(n)
add attributes to an existing relation
Alter table
a variable length character string user specified maximum length n
varchar(n)
A fixed-point number with user-specified precision
numeric (p,d)
matches any string with exactly three letters
three underscore
provide commands for defining relation schemas, deleting relation and modifying relation schemas
Data Definition Language (DDL)
for defining views
View definition
IBM developed the original version of SQL called Sequel as part of the System R Project
Early 1970s
causes tuple in the result of a query to appear in sorted order
Order by
Published and extended SQL standard, SQL-89
1989
may also contain arithmetic expression involving +, -, * and /
select clause
deletes all the information about the dropped relation from the database
Drop table
Has clearly established itself as the standard relational database language
Sequel
floating point and double precision floating point number with machine dependent precision
real, double precision
simplify where clause that specify a value be less than or equal to some value and greater than or equal to some other value
Between
