IS 201 Exam 1
table
A collection of rows and columns
What is a null field and how is it handled in a query?
Absence of data in a cell
What is a summary query?
Also called a group by. Clumps contents of table.
What is the difference between using "and" and using "or" for the criteria in a query?
And is for two conditions. Or is for one
What are criteria in a query, how is it defined?
Area in the SELECT query window used to identify which rows should appear in the result table.
relationship
Association between entities
What are the general data types available in Access?
Categorical, Numerical, Discrete, Continuous
What does it mean to sort data in a query?
Change the way the query data appears
entity
Collection of attributes describing object of interest
What is a comparison (aka relational) operator?
Compares two things
What is a foreign key?
Connects the two tables so that database can follow
foreign key
Connects the two tables so that database can follow
row
Consist of a single record
What are the benefits and drawbacks for using a DBMS vs. a spreadsheet to store data?
DBMS can organizes data into fields and records but spreadsheet stores data in a grid of rows and columns allowing for calculations and the generation of graphs. 2. DBMS performs on Data Quality check means database allows for certain variables to be set as the only possible entries but in Spreadsheets allow value categories such as numbers, but not the customization of the database. 3. DBMS by default allows data from multiple source to be integrates into one database bit in spreadsheet it requires other applications or custom program to allow this feature. 4. Efficiency for database is more easier rather than spreadsheet Cost is higher for DBMS rather than using spreadsheet. 2. If you want your data public then Spreadsheet is more easier rather than DBMS. 3. In DBMS it requires expert for maintaining the data but in spreadsheet it does not require any technical expert. 4. If you does not have huge data then spreadsheet is more profitable.
What is data redundancy?
Data is repeated
What is a query?
Data stored in a database into information for decision making
What types of data are stored on a computer?
Data, Numerical, Discrete, Continuous, Categorical.
What is the difference between using a database vs. spreadsheet to store data?
Database is minimally redundant (use keys to link). Has redundant data (duplicated)
What is a many-to-many relationship?
Each entity can have many things
What is referential integrity?
Ensures that there are no dangling foreign keys
How do you perform calculations in a query?
Enter calculation in field
In examples of a 1:M (one-to-many) relationship, where will the foreign key be stored? How can we work it out?
FK goes in the many table
What are the features of a DBMS?
Flexible, Many Filters
What are some issues that can arise when importing data from an outside source into a DBMS? What are some tools or ways to resolve these issues?
Format is not the same. Number of fields doesn't match. Size of data is more than DBMS. Security Issues, cannot be read. Use query, use SQL.
column
Have a data type
What the benefits and drawbacks of using a DBMS?
Improved access, improved security, Increased costs, complexity
How can data stored in an Access database?
In tables
What does the lookup wizard do in a table in Access?
Lets a table contain data that is referenced by another table
What is an example of a business application system? Why do people create business application systems?
Microsoft Access, Excel, Outlook. They increase productivity, and measure productivity and to perform other functions accurately.
What is a parameter driven query?
Most common error, database asking for input
What are the goals of database design?
No redundancy,
primary key
One candidate key chosen by the database designer
What are action queries and what are they used for?
Permanently modify your database
Why do we store data in a database?
Protect data, accessible, adaptable.
Why do organizations usually store data in a database?
Protects the data, accessible, adaptable.
What is an input mask?
Restricts the data that can be entered in a field
What is a DBMS?
Set of soft ware that facilitates storage and access of data on a computer.
cell
Smallest unit in access
What are data types and why do you have to choose a data type for each attribute when creating a table with a database management system?
So that you can pull data together.
Database management system
Software that allows you to use a computer to create a database
What is an ER (Entity-Relationship) diagram?
Structural diagram,
What is referential integrity?
System of rules that Microsoft Access uses to ensure that relationship data is valid and that you cannot accidentally delete a record in one table if a matching record is present in a related table.
Why do tables have to be related in Access for queries to work correctly?
Tables have to related in Access for queries to work correctly because it creates the relationship between multiple tables for access the data that will reflect in our result like if we define a field in our query but that field is not present is the table then it will give us dump or it will not work. If the data is related in access for queries the it will quickly fetch the data into DBMS and make it easier for read/write or change the data into our system.
What are the 4 objects in an Access database?
Tables, Queries, Forms, Reports
What is a logical operator?
Tests "and/or" tests
What is a primary key?
This uniquely identifies each record in the db.
What is the IIF function, what are the components of the function and why is it used?
Three arguments, Expression, True, False. Used to test if true or false
What is the difference between creating a relationship in the relationship window and using the lookup wizard?
Using a lookup wizard, creates foreign key that refers back to primary key of another.
What is a natural vs. artificial/surrogate key?
Values are distinct over all possible values
What is the difference between enforcing referential integrity and just creating a relationship between tables?
Values can be NULL
Database
a collection of organized data that allows access, retrieval, and use of data
What is a database constraint?
a restriction that determines what is allowed to be entered or edited in a table
database constraint
a restriction that determines what is allowed to be entered or edited in a table
How do you concatenate fields in a query?
concatenate(col1, col2,...)
attribute
data item describing a property of interest
field
defined by its name, type, size and format
data type
indicates the type of data that can be stored in a field
How does a query differ from a table?
table contains structure of data, constraints andd actual data. Query is a way to look at data.
data value
the actual value stored in a field
What is produced by a query?
virtual table or result table