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Queries in PostgresSQL

DDL was used to create tables, update the fields in an existing table. A set of commands were used to manipulate data stored in database.

Data Engineering

Using the information to create a table schema for each of the six CSV files
Specifing data types, primary keys, foreign keys, and other constraints
Import each CSV file into the corresponding SQL table

Data Analysis

Listing the following details of each employee: employee number, last name, first name, gender, and salary
Listing employees who were hired in 1986
Listing the manager of each department with the following information: department number, department name, the manager's employee number, last name, first name, and start and end employment dates
Listing the department of each employee with the following information: employee number, last name, first name, and department name
Listing all employees whose first name is "Hercules" and last names begin with "B"
Listing all employees in the Sales department, including their employee number, last name, first name, and department name
Listing all employees in the Sales and Development departments, including their employee number, last name, first name, and department name
In descending order, listing the frequency count of employee last names, i.e., how many employees share each last name

Queries Used

Data Definition Language Statements:

CREATE TABLE
ALTER
DROP
CREATE VIEW
DROP VIEW

Data Manipulation Language Statements:

SELECT
APPEND
DELET
UPDATE
JOIN

Aggregate Functions:

SUM
COUNT
GROUP BY
WHERE

Data Modeling

Inspecting the CSVs and sketching out an ERD of the tables