SQL Flashcards
What Does SQL Stand For?
Structured Query Language
Where Do Most Companies Store Their Data?
In Databases
What is a Relational Database?
A relational database is a database that stores related information across multiple tables and allows you to query information in more than one table at the same time.
What is SQL Used For?
SQL is Used to Communicate with Databases
A Relational Database Contains One or More Objects Called……?
Tables
What is the ‘Select’ Statement Used For?
It is used to query the database and retrieve selected data that matches the criteria that you specify.
What is the ‘Create Table’ Statement Used For?
To Create a new Table
What is the ‘Insert’ Statement Used for?
The insert statement is used to insert or add a row of data into the table
What is the ‘Update’ Statement Used for?
The update statement is used to update or change records that match a specified criteria
What is the ‘Delete’ statement Used for?
The delete statement is used to delete records or rows from the table.
Who at IBM Developed SQL?
Raymond Boyce and Donald Chamberlin developed SQL at IBM in the early 1970s
What Does ANSI Stand For?
American National Standards Institute
What Does ISO Stand For?
International Organisation for Standardisation
Information is Stored in Tables and, in Turn, the tables are Stored in…….?
Databases
What Does DBMS Stand For?
Database Management System
What Does DDL Stand For?
Data Definition Language
What Does DML Stand For?
Data Manipulation Language
What Do Tables Consist of?
Columns and Rows
What are the Commands that we use to Retrieve Information from a Database Called?
Queries
Where are the SQL Commands Written?
In a Command Editor
What is the Process the Database Follows when it Receives an SQL Query
1 - Sees Query 2 - Looks at 'FROM' to Identify Table 3 - Looks at Condition (WHERE) to Eliminate Rows 4 - Looks at SELECT to Eliminate Columns 5 - Displays Results
Although SQL isn’t Case Sensitive, what do we Need to Ensure about text held between the Parenthesis?
We have to ensure that the text between the parenthesis is EXACTLY the same as it is in the database.
What are Operators Used For?
Operators are Used to Compare Information
What are the 6 Operators we Use?
> Greater Than < Less Than = Equals To != Not Equals To >= Greater Than or Equal To <= Less Than or Equal To