TestOut 7.2 & 7.3

Query

A method of asking questions about the data stored in a database.

Report

A report is a formatted, easy-to-read listing of the results of a query.

Database

A structured set of data held in a computer, usually in a way that is accessible by multiple concurrent users.

Data Modeling

A way to help programmers and other related parties make sense of database information - complex business flow

Report

An easy-to-read listing of the results of a query. (Summary)

Query

Queries are used to ask questions about the data stored in a database's tables. Generally, it's not useful to look at an entire data table. Instead, database users build queries, which retrieve only the relevant information they want to look at. For example, if you've ever searched for a single TV show from a streaming service, you've queried a database. Can also update, edit and delete information. A query will result in information that resembles a spreadsheet with rows and columns.

Primary Key

This unique identifier is called a primary key. If you have a driver's license, the license number is a primary key.

Market data

Use this data type to gauge markets trends in order to decide what to do in the present, such as which companies to invest in.

Databases

are electronic repositories of organized information.

A field

describes a single attribute of each record in a table. For example, in a database of people you may have a field for first names. Every person's first name will be stored in the first name field.

Conceptual Data Models

focuses only on high-level concepts. This data model answers the question of what a system contains.

Relational databases

have many advantages over flat file databases, which typically store data in a single file in plain text format.

In a relational database, one-to-may relationships are

usually represented by two tables linked together by a foreign key.

Fields

§are comparable to comparable to columns on a spreadsheet.

Table

A data structure in a relational database that is comprised of fields (columns) and records (rows).

Form

A form builds the query automatically (user-friendly). Example: Search engine. When you enter your search terms and press enter, the information from the form is plugged into a query, which then retrieves your information.

Form

A graphical interface that allows users to query a database by filling in information on the form. Provides an easy way for users to enter data into tables

Relational Database Facts

Advantages include support for organization, concurrent users, scalability, speed of access, and support for a variety of data types.

Foreign Key

Often, a table in a database will reference records in another table. They do this by using the primary key value of the record they want to reference. When a table uses a primary key from another table, it's called a foreign key. A foreign key is used when a table in a database will reference records in another table.

Table

Tables are used to store the information in a relational database. Each table is comprised of fields (columns) and records (rows).

This is called a NOT NULL constraint

The schema of a database can prevent some fields from being left blank. It requires a value to be entered into the field whenever a new record is created.

A one-to-many relationship

exists when only one side of the relationship is unique. For example, a single building may contain many classrooms, but each classroom is inside only one building.

A foreign key

is a column that refers to a primary key that exists in another table. These values can be duplicated, and this allows an entry to reference a value from another table.

A primary key

is found in one or more columns of data and contains a unique identifier for the row (like a home address).

Analytical data

is historical data that's used to help people make decisions in the present. I

Operational data

is simply data that's produced by an organization's everyday operations. It's data that's gathered in real time to provide a snapshot of what's happening in the present.

A Database management system (DBMS)

is software that allows users to define, manipulate, retrieve, and manage data stored in a database. Types: MySQL - an open-source system Microsoft Access - create and manage small databases