
Primary Key:
A primary key in a
Example:
- Students in Universities are assigned a unique registration number.
- Therefore, in a STUDENT database table, the attribute “reg_no” acts as primary key.
Foreign Key:
Foreign key is a column in a relational database table which provides a relation between two tables. It provides a cross reference between tables by pointing to primary key of another table.
Example:
- In STUDENT database table, the attribute “reg_no” acts as primary key and in COURSE database table in which the student selects his or her course, the same “reg_no” acts as foreign key for the STUDENT table.
Many to One relationship:
When more than one record in a database table is associated with only one record in another table, the relationship between the two tables is referred as many to one relationship. It is also represented as M: 1 relationship.
One to Many relationships:
When one record in a database table is associated with more than one record in another table, the relationship between the two tables is referred as one to many relationships. It is also represented as1: M relationship. This is the opposite of many to one relationship.
CROW FOOT ERD:
The Crow Foot ERD is an Entity Relationship Diagram which is used to represent the cardinalities present in the basic ER diagram. It is used to represent the relationships present between two tuples or tables present in the database.

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Chapter 3 Solutions
Database Systems: Design, Implementation, & Management
- I need help fixing the minor issue where the text isn't in the proper place, and to ensure that the frequency cutoff is at the right place. My code: % Define frequency range for the plot f = logspace(1, 5, 500); % Frequency range from 10 Hz to 100 kHz w = 2 * pi * f; % Angular frequency % Parameters for the filters - let's adjust these to get more reasonable cutoffs R = 1e3; % Resistance in ohms (1 kΩ) C = 1e-6; % Capacitance in farads (1 μF) % For bandpass, we need appropriate L value for desired cutoffs L = 0.1; % Inductance in henries - adjusted for better bandpass response % Calculate cutoff frequencies first to verify they're in desired range f_cutoff_RC = 1 / (2 * pi * R * C); f_resonance = 1 / (2 * pi * sqrt(L * C)); Q_factor = (1/R) * sqrt(L/C); f_lower_cutoff = f_resonance / (sqrt(1 + 1/(4*Q_factor^2)) + 1/(2*Q_factor)); f_upper_cutoff = f_resonance / (sqrt(1 + 1/(4*Q_factor^2)) - 1/(2*Q_factor)); % Transfer functions % Low-pass filter (RC) H_low = 1 ./ (1 + 1i * w *…arrow_forwardMy code is experincing minor issue where the text isn't in the proper place, and to ensure that the frequency cutoff is at the right place. My code: % Define frequency range for the plot f = logspace(1, 5, 500); % Frequency range from 10 Hz to 100 kHz w = 2 * pi * f; % Angular frequency % Parameters for the filters - let's adjust these to get more reasonable cutoffs R = 1e3; % Resistance in ohms (1 kΩ) C = 1e-6; % Capacitance in farads (1 μF) % For bandpass, we need appropriate L value for desired cutoffs L = 0.1; % Inductance in henries - adjusted for better bandpass response % Calculate cutoff frequencies first to verify they're in desired range f_cutoff_RC = 1 / (2 * pi * R * C); f_resonance = 1 / (2 * pi * sqrt(L * C)); Q_factor = (1/R) * sqrt(L/C); f_lower_cutoff = f_resonance / (sqrt(1 + 1/(4*Q_factor^2)) + 1/(2*Q_factor)); f_upper_cutoff = f_resonance / (sqrt(1 + 1/(4*Q_factor^2)) - 1/(2*Q_factor)); % Transfer functions % Low-pass filter (RC) H_low = 1 ./ (1 + 1i * w *…arrow_forwardI would like to know the main features about the following three concepts: 1. Default forwarded 2. WINS Server 3. IP Security (IPSec).arrow_forward
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