
# Introduction
Knowledge has turn out to be a better commodity to retailer within the present digital period. With the benefit of getting plentiful information for enterprise, analyzing information to assist corporations acquire perception has turn out to be extra important than ever.
In most companies, information is saved inside a structured database, and SQL is used to amass it. With SQL, we are able to question information within the kind we would like, so long as the script is legitimate.
The issue is that, typically, the question to amass the info we would like is advanced and never dynamic. On this case, we are able to use SQL saved procedures to streamline tedious scripts into easy callables.
This text discusses creating information analytics automation scripts with SQL saved procedures.
Curious? Right here’s how.
# SQL Saved Procedures
SQL saved procedures are a group of SQL queries saved instantly inside the database. In case you are adept in Python, you may consider them as capabilities: they encapsulate a collection of operations right into a single executable unit that we are able to name anytime. It’s useful as a result of we are able to make it dynamic.
That’s why it’s useful to grasp SQL saved procedures, which allow us to simplify code and automate repetitive duties.
Let’s strive it out with an instance. On this tutorial, I’ll use MySQL for the database and inventory information from Kaggle for the desk instance. Arrange MySQL Workbench in your native machine and create a schema the place we are able to retailer the desk. In my instance, I created a database referred to as finance_db
with a desk referred to as stock_data
.
We will question the info utilizing one thing like the next.
USE finance_db;
SELECT * FROM stock_data;
Normally, a saved process has the next construction.
DELIMITER $$
CREATE PROCEDURE procedure_name(param_1, param_2, . . ., param_n)
BEGIN
instruct_1;
instruct_2;
. . .
instruct_n;
END $$
DELIMITER ;
As you may see, the saved process can obtain parameters which are handed into our question.
Let’s study an precise implementation. For instance, we are able to create a saved process to mixture inventory metrics for a particular date vary.
USE finance_db;
DELIMITER $$
CREATE PROCEDURE AggregateStockMetrics(
IN p_StartDate DATE,
IN p_EndDate DATE
)
BEGIN
SELECT
COUNT(*) AS TradingDays,
AVG(Shut) AS AvgClose,
MIN(Low) AS MinLow,
MAX(Excessive) AS MaxHigh,
SUM(Quantity) AS TotalVolume
FROM stock_data
WHERE
(p_StartDate IS NULL OR Date >= p_StartDate)
AND (p_EndDate IS NULL OR Date <= p_EndDate);
END $$
DELIMITER ;
Within the question above, we created the saved process named AggregateStockMetrics
. This process accepts a begin date and finish date as parameters. The parameters are then used as circumstances to filter the info.
You possibly can name the saved process like this:
CALL AggregateStockMetrics('2015-01-01', '2015-12-31');
The process will execute with the parameters we go. Because the saved process is saved within the database, you should utilize it from any script that connects to the database containing the process.
With saved procedures, we are able to simply reuse logic in different environments. For instance, I’ll name the process from Python utilizing the MySQL connector.
To do this, first set up the library:
pip set up mysql-connector-python
Then, create a perform that connects to the database, calls the saved process, retrieves the consequence, and closes the connection.
import mysql.connector
def call_aggregate_stock_metrics(start_date, end_date):
cnx = mysql.connector.join(
person="your_username",
password='your_password',
host="localhost",
database="finance_db"
)
cursor = cnx.cursor()
strive:
cursor.callproc('AggregateStockMetrics', [start_date, end_date])
outcomes = []
for lead to cursor.stored_results():
outcomes.prolong(consequence.fetchall())
return outcomes
lastly:
cursor.shut()
cnx.shut()
The consequence will probably be just like the output under.
[(39, 2058.875660431691, 1993.260009765625, 2104.27001953125, 140137260000.0)]
That’s all you have to find out about SQL saved procedures. You possibly can prolong this additional for automation utilizing a scheduler in your pipeline.
# Wrapping Up
SQL saved procedures present a way to encapsulate advanced queries into dynamic, single-unit capabilities that may be reused for repetitive information analytics duties. The procedures are saved inside the database and are simple to make use of from completely different scripts or purposes resembling Python.
I hope this has helped!
Cornellius Yudha Wijaya is a knowledge science assistant supervisor and information author. Whereas working full-time at Allianz Indonesia, he likes to share Python and information ideas through social media and writing media. Cornellius writes on quite a lot of AI and machine studying subjects.