02 Section 5 - File Handling and Storing Data

Question 1

What is the first thing you have to do when dealing with file handling?

Answer 1

Open the external file using an open command and assigning it to a variable

Question 2

What is an open command in Read mode?

Answer 2

newFile = openRead(“newfile.txt”)

-sometimes you have to give the whole file path, not just the file name

Question 3

What is an open command in Write mode?

Answer 3

newFile = openWrite(“newfile.txt”)

-sometimes you have to give the whole file path, not just the file name

Question 4

What are the two modes you can open files in?

Answer 4

Read

Write

Question 5

What is read mode for opening a file?

Answer 5

It allows you to read data from the external file into your program

Question 6

What is write mode for opening a file?

Answer 6

It allows you to write data from your program to an external file

Question 7

When a file is opened where does it start reading or writing from?

Answer 7

The beginning of the file

-as you read from or write to the file, the program keeps its place in the file

Question 8

What is the last thing you should do when dealing with file handling?

Answer 8

You should close the file

-if you forget to close it then a file can remain locked and prevent others from editing it

Question 9

What is the close command for file handling?

Answer 9

newFile.close()

Question 10

How can you write to a file once it is opened?

Answer 10

newFile.writeLine()

-if the file already contains some text, then it will overwrite what is currently there

Question 11

How can you read from a file once it is opened?

Answer 11

newFile.readLine()

-the program will always start reading from the first line of the external file

Question 12

What is the file handling command which returns TRUE when the program is at the end of an external file?

Answer 12

newFile.endOfFile()

-used to signify when a program should stop reading a file

Question 13

What do data bases order data into?

Answer 13

Fields (columns) and records(rows)

Question 14

What do databases store data in?

Answer 14

Tables, made up of fields and records

Question 15

What is a field?

Answer 15

A field is used to store a category

-a column of the table

Question 16

What is a record?

Answer 16

A record uses the field to store details about a specific item
-a row of the table

Question 17

What is the difference in data types between fields and records?

Answer 17

• all data in the same field has to have the same data type

- all data in the same record can have different data types

Question 18

What does each table in a database have?

Answer 18

a primary key

Question 19

What is a primary key?

Answer 19

A field which can uniquely identify any record in the table

-there is only one primary key field per data base table

Question 20

What are the two types of database?

Answer 20

flat-file

relational

Question 21

What is a flat-file database?

Answer 21

Databases that only have one table, which can be viewed by opening one data file

Question 22

What is a relational database?

Answer 22

Databases that combine flat-file databases, the different tables are linked together by key fields

Question 23

What does SQL stand for?

Answer 23

Structured query language

Question 24

What is SQL?

Answer 24

A language that can create, update and query databases

-it consists of commands called statements

Question 25

What is the first thing every database needs?

Answer 25

a table

Question 26

What is the SQL statement for creating a table?

Answer 26

CREATE TABLE tablename (primarykeyfieldname DATATYPE PRIMARY KEY, fieldname2 DATATYPE, fieldname3 DATATYPE ... );

Question 27

What do you need to specify for each field in a table?

Answer 27

The data type

Question 28

What are common SQL data types?

Answer 28

``` INTEGER REAL TEXT DATE BOOLEAN ```

Question 29

What is the SQL statement for adding complete records to an empty table?

Answer 29

INSERT INTO tablename VALUES (data, data2, data3 ...);

Question 30

What is the SQL statement for adding incomplete records to an empty table?

Answer 30

INSERT INTO tablename (field, field2, field3 ...) VALUES (data, data2, data3 ...);

Question 31

What is the SQL statement for updating a record?

Answer 31

UPDATE tablename SET field = data WHERE primarykeyfieldname = number;

Question 32

When retrieving information from a database wheat are the key SQL statements?

Answer 32

SELECT | FROM;

Question 33

What does a SELECT statement in SQL do?

Answer 33

Used to tell the database what information you want it to retieve

Question 34

What does a FROM statement in SQL do?

Answer 34

Tells the database which tables to look in

Question 35

What is the SQL statement for retrieving data from a database?

Answer 35

SELECT field, field2 ... | FROM tablename;

Question 36

What is the SQL wildcard for all the fields?

Answer 36

*

Question 37

Why do you use a WHERE SQL statement?

Answer 37

To specify conditions that a record must satisfy before it is returned

Question 38

What is the SQL statement for retrieving data from a database with specified conditions?

Answer 38

SELECT * FROM tablename | WHERE condition;

Question 39

What conditions can be used with the WHERE SQL statement?

Answer 39

Comparison operators Boolean operators - AND, OR LIKE statements (to search for a pattern)

Question 40

What are the SQL wildcards you can use?

Answer 40

* (to return all fields) | % (used in LIKE statements to represent any combination of letters or numbers)

Question 41

What is the SQL statement for retrieving data from a database with specified conditions of partial information?

Answer 41

SELECT * FROM tablename | WHERE field LIKE "%parital information%";

Question 42

What is the SQL statement for retrieving data from a database in an order?

Answer 42

ORDER BY field ASC; -sort records ACS (ascending) or DECS (descending) order