add basic sqlite3 analysis script

4 files changed, 79 insertions, 0 deletions

diff --git a/projects/sqlite3-analysis/README.md b/projects/sqlite3-analysis/README.md
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index 0000000..18a1a43
--- /dev/null
+++ b/projects/sqlite3-analysis/README.md
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+## Instructions
+
+```bash
+# Open the database:
+sqlite3 ./chinook.db
+```
+
+```sql
+# Enable some features and export the CSV results of the script
+.headers on
+.mode csv
+.output /home/cmc/git/data-science/projects/sql-dashboard/employee_sales.csv
+.read employee_sales.sql
+```
+
+```bash
+# Inspect the results
+cat ./employee_sales.csv
+```
+
+```csv
+EmployeeId,LastName,FirstName,Title,CustomerId,SupportRepId,State,Country,InvoiceId,CustomerId,InvoiceDate,InvoiceId,UnitPrice,Quantity,TotalPrice
+3,Peacock,Jane,"Sales Support Agent",1,3,SP,Brazil,98,1,"2010-03-11 00:00:00",98,1.99,1,1.99
+4,Park,Margaret,"Sales Support Agent",4,4,,Norway,2,4,"2009-01-02 00:00:00",2,0.99,1,0.99
+5,Johnson,Steve,"Sales Support Agent",2,5,,Germany,1,2,"2009-01-01 00:00:00",1,0.99,1,0.99
+```
diff --git a/projects/sqlite3-analysis/chinook.db b/projects/sqlite3-analysis/chinook.db
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index 0000000..2ede95c
--- /dev/null
+++ b/projects/sqlite3-analysis/chinook.db
diff --git a/projects/sqlite3-analysis/employee_sales.csv b/projects/sqlite3-analysis/employee_sales.csv
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+++ b/projects/sqlite3-analysis/employee_sales.csv
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+EmployeeId,LastName,FirstName,Title,CustomerId,SupportRepId,State,Country,InvoiceId,CustomerId,InvoiceDate,InvoiceId,UnitPrice,Quantity,TotalPrice

+3,Peacock,Jane,"Sales Support Agent",1,3,SP,Brazil,98,1,"2010-03-11 00:00:00",98,1.99,1,1.99

+4,Park,Margaret,"Sales Support Agent",4,4,,Norway,2,4,"2009-01-02 00:00:00",2,0.99,1,0.99

+5,Johnson,Steve,"Sales Support Agent",2,5,,Germany,1,2,"2009-01-01 00:00:00",1,0.99,1,0.99

diff --git a/projects/sqlite3-analysis/employee_sales.sql b/projects/sqlite3-analysis/employee_sales.sql
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+++ b/projects/sqlite3-analysis/employee_sales.sql
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+-- Data ETL business script in sqlite3
+
+-- Create new field(s) for business-requested calculations
+ALTER TABLE invoice_items
+ADD COLUMN TotalPrice
+GENERATED ALWAYS AS (UnitPrice * Quantity);
+
+-- Extract and summarize data to show sales totals per employee
+WITH cst AS (
+	SELECT
+		CustomerId
+		,SupportRepId
+		,State
+		,Country
+	FROM customers
+),
+emp AS (
+	SELECT
+		EmployeeId
+		,LastName
+		,FirstName
+		,Title
+	FROM employees
+),
+inv AS (
+	SELECT
+		InvoiceId
+		,CustomerId
+		,InvoiceDate
+	FROM invoices
+),
+tot AS (
+	SELECT
+		InvoiceId
+		,UnitPrice
+		,Quantity
+		,TotalPrice
+	FROM invoice_items
+)
+
+SELECT DISTINCT * FROM emp
+LEFT JOIN cst ON emp.EmployeeId = cst.SupportRepId
+LEFT JOIN inv ON cst.CustomerId = inv.CustomerId
+LEFT JOIN tot ON inv.InvoiceId = tot.InvoiceId
+WHERE inv.InvoiceDate <= date()
+GROUP BY EmployeeId;
+
+-- Drop col used for calculations
+ALTER TABLE invoice_items DROP TotalPrice;