Databases

Lab 1 - January 10th, 2017

SqLite

How we access data is we use these things called queries.

In the terminal type in:

sqlite3

and then

.read FILENAME.sql

and then

select * from characters;

Order matters when running select in the terminal from the database. It is not case sensitive.

Ex. You can use FROM, ChaRacters, Select, ect.

select dinstinct Applies only to what follows, and makes it so only unique data gets return.

sql select distinct title from characters;

Notes: You can have an or in your where.

 select * from characters where title = 'Horton Hears a Who' or title = 'Horton Hatches the Egg';

Ex. You can order your return.

sql select name, year from characters order by year, title;

Aggregate function

• count
• max
• min
• avg

Lab 2 - January 17th, 2017

Flowcharts

• Rounded Rectangle -> Start and Stop
• Rectangle -> Process
• Diamond -> Decision
  • Yes or No
• Italic Rectangle -> Data Input or Output

Communicate an algorithm

• Easy
• Visual
• Simple for hard problems

Criteria for lab assignment

• Flowchart:
  • Draw by hand or
  • Draw with https://draw.io

You should know how to:

• Convert Pseudocode to Flowchart and Flowchart to Pseudocode

Lab Exercise: Draw a flowchart for playing 1 turn of "computer pictionary"

• 2 teams (Team A and B)
• Only using names of movies
• Computer draws movie name (if it can)
• 5 guesses

N.B. Team A draws a name -> Team A inputs name into computer -> Team B guesses (Max. 5 times)

My Solution:

Group Solution:

PseudoCode Exercise: Get the name and title of books where there is a 1 and the year in lesser than 1960

Table 1: Characters

name	title	year	human
example	example	1983	1
example2	example2	1924	0
example3	example3	1999	1

Answer: Select name, title from characters where human=1 and year<1960

Lab 3 - January 24th, 2017

Hex to Binary To Decimal

Dec	Hex	Binary
0	0	0000
1	1	0001
2	2	0010
3	3	0011
4	4	0100
10	A	1010
11	B	1011
12	C	1100
13	D	1101
14	E	1110
15	F	1111

Binary to Hex

0010	1101	1111
2	D	F

Hex to Dec

2	D	F
16(2)	16(1)	16(0)

= Big Number

2's compliment

Note: Number of bits need to be even

Ex: Positive number in 2's complement

+28 = 28 in binary

Lab 4 - January 31st, 2017

• OR (+)
• And (*)
• XOR (circleX)
• Not (~)

Truth Tables -> Circuit Diagram

A) Draw a diagram of an OR gate using only AND and NOT gates.

B) Draw a circuit diagram for an AND gate using only OR and NOT gates.

The "OR and ANDS" Rule

OR, AND, NOT gates

A	B	C
0	0	0
0	1	1
1	0	0
1	1	1

1. Look at only to inputs with 1 output.
2. A is 0 -> Not gate
3. B is 1 -> Nothing
4. an AND those two
5. A is 1 -> Nothing
6. B is 1 -> Nothing
7. and AND those two
8. put both those paths to an OR gate

---

Note: Doing AND for two inputs and then AND that input with a third input is the same as AND for three inputs.

Lab 5 - February 7th, 2017

Sorting

Selection Sort vs. Bubble Sort

Selection Sort

List of numbers [64, 25, 12, 22, 11]

n=5
min position = "position of min"
min = "min for index i"
i = "index for next sorted number"
j = "index to compare as next min"

1. Look at index 1
2. Find the lowest number in the list and switch it with the first position.

[11, 25, 12, 22, 64]

1. Look at index 2
2. Find the new min
3. Is the number lower than that of index 2

[11, 12, 25, 22, 64]

ect. 

[11, 12, 22, 25, 64]

1. Look at the last two in the array

Bubble Sort

List of numbers [5, 1, 4, 2, 8]

n=5
i = N
j = ""

Wikipedia page on bubble sort