9. Using Databases Flashcards
What kind of system is Microsoft Excel?
Flat file system
One way databases differ from flat file systems?
Databases support concurrent users without locking the database.
Flat file systems may support concurrent users, but it usually becomes locked to other users or restricted to read-only
Meaning of RDBMS?
Relational Database Management System
Describe relational databases (RDBMS)
Data is structured in tables, each defined by fields corresponding to its columns.
RDBMS typically use SQL to maintain data in databases
i.e. Microsoft SQL Server, Oracle Database, MySQL, Microsoft Office Access
What are database interfaces?
Processes used to manage databases
add/update & extract data
What’s used in RDBMS to create/update databases?
SQL relational methods
Data Definition Methods
What are DDL commands?
Data Definition Language
SQL commands altering the database’ structure
i.e. CREATE - adds databases or tables with specified primary & foreign keys
Data Manipulation Methods
Purpose of DML commands?
Data Manipulation Language
Insert/update records & extract data for viewing
A query
i.e. INSERT INTO TableName - adds a new row in a table in the database
Purpose of database access methods?
To run SQL commands or use graphical tools for data tasks
App architecture models
When is an app considered one-tier or standalone?
Front-end, processing logic, & database engine are hosted on same client
When is an app considered two-tier?
Front end & processing logic is hosted on client; Database engine is hosted on server
When is an app considered three-tier?
Front-end, processing logice, & database engine are hosted on separate systems
What does programmatic access mean?
Allowing apps to interact with systems via APIs
allows apps to interact with databases using SQL commands or stored procedures
An INSERT statement is an example of what data language type?
Data Manipulation Language
