SQL Select Statement Capabilities Quiz

Study Notes

Data Basics

Data refers to facts, absence, assumptions, or occurrences
A database is an organized collection of information
Data storage units on a computer include:
- Bit: the smallest unit of data storage
- Nibble: a 4-bit unit of data or half of a byte
- Byte: a unit of data equivalent to eight binary digits

Data Processing Cycle

Gathering information or data
Data encoding and input
Database processing and calculation
Output and saving or storing results

Data Accessing Methods

Manual method: using pen and paper
Mechanical method: using keyboard and typewriter
Electronic method: using computers

Data Processing Modes

Batch processing: the most inexpensive and efficient method for large organizations
On-line processing: transactions are entered directly into the computer and processed immediately

Database SQL Concepts

RDBMS: Relational Database Management System
Table: a collection of related data entries with rows and columns
Field: a column in a table that is designed to maintain specific information about every record
Record: an individual entry that exists in a table
Column: a vertical entity in a table that contains all related data
Null value: a value in a field with no value
Constant: a something with a fixed value
Variable: something that may have a varying value over time
Operators: come as input for operators
Expression: a well-formed string containing variables, constants, or functions

Database Security

Controlling database access is an important matter in database management
User: an account that can connect and access objects within the database
Schema: a group of database objects such as tables, views, clusters, procedures, and packages
Authentication: means verifying the identity of someone who wants to use data resources or application

Capabilities of SQL Select Statement

Projection: selecting certain columns or fields from a table
Selection: retrieving a subset of rows or records in a table that satisfy a condition
Joining: combining data from more than one column or table
Generating report: using the output of the select statement to create a report
Basic select statement: SELECT * FROM tablename
Using arithmetic expressions and null values
Using the WHERE clause to specify conditions
Using the ORDER BY clause to arrange data in ascending or descending order

Description

Test your knowledge on the capabilities of SQL select statements and related data concepts like data storage units and binary data. Learn about data organization in databases and data processing. This quiz covers various aspects of data management and storage.