SQL

terms

sql-ddl

(Data Definition Language) das erstellen/ändern/löschen von datenbankstrukturen (tables, fields, views, ...)

sql-dml

(Data Manipulation Language) das erstellen/ändern/löschen des inhalts (daten) der datenbankstrukturen

sql-dcl

(Data Control Language) Transaktionskontrolle und Zugriffsberechtigungen

sql-injection

transaktionen

attribut

index

commands

such as "Select", "Insert", "Update", "Delete", "Create", and "Drop"

tables

are uniquely identified by their names and are comprised of columns and rows.

columns

contain the column name, data type, and any other attributes for the column.

rows

contain the records or data for the columns.

the where-clause

optional specifies which data values or rows will be returned (criterias: =, <>, <, >, >=, <=, like)

tuple

is a collection of one or more attributes or rows present in a table

constraints

are uses to limit the values of variables NOT NULL; UNIQUE; PRIMARY KEY; FOREIGN KEY; CHECK; DEFAULT

subquery

aggregat functions

avg(); count(); count(dinstinct field); max(); ...

scalar functions

ucase(), lcase(), mid(), len(), left(), right(), round(), mod(), now()

olap cube() rollup()