Module 4 Flashcards
Database
An organized collection of information or data
Spreadsheets
Designed for a single user or a small team
Store less data
Databases
Accessed by multiple people simultaneously
Store massive amounts of data
Perform complex tasks while accessing data
Relational Database
A structured database contains by tables that are related to each other
Primary Key
A column where every row has a unique entry
Foreign Key
A column in a table that is a primary key in another table
SQL (Structured Query Language)
A programming language used to create, interact with. And request information from a database
Query
A request for data from a database table or a combination of tables
Log
A record of events that occur within an organizations systems
Select
Indicates which columns to return
From
Indicates which table to query
Syntax
The rules that determine what is correctly structured in a computing language
Filtering
Selecting data that match a certain condition
Where
Indicates the condition for a filter
Like
Used with WHERE to search for a pattern in a column
Common Data Types
String
Numeric
Date and Time
String Data
Data consisting of an ordered sequence of characters
Date and Time Data
Data representing a date and/or time
Operators
=
>
<
<>
> =
<=
Between
An operator that filters for numbers or dates within a range
And
Specifies that both conditions must be met simultaneously
Or
Specifies that either condition can be met
Not
Negates a condition
Inner Join
Returns rows matching on a specified column that exists in more than one table
Types of Outer Joins
Left Join
Right Join
Full Outer Join
Left Join
Returns all of the records of the first table, but only returns rows of the second table that match on a specified column
Right Join
Returns all of the records of the second table, but only returns rows from the first table that match on a specified column
Full Outer Join
Returns all records from both tables
