MagnaDataSolutions.com
Getting started with the
SQL Language
Cecilia Brusatori
Magna Data Inc

MagnaDataSolutions.com
Cecilia Brusatori
ready
Founder and CEO of Magna Data inc​
Data Analytics Solutions and Corporate Training
University Graduate Degree in Computer Science
& Engineering
Tech Community Leader & Organizer in South
Florida US
Proudly Nerd​ - Always Learning - Naturist –
Love Animals, good Books & the Beach
Entrepreneur - Consultant, Trainer, Speaker
Miami/Fort Lauderdale Area

MagnaDataSolutions.com
Agenda
 DBs Concepts & Terminology
 Intro to SQL Language
 DML Syntax: SELECT, UPDATE, INSERT, DELETE
 Exploring SELECT
 WHERE, Operators
 Aggregations
 Group By, Having
 Types of Joins

MagnaDataSolutions.com
Databases
Concepts & Terminology

MagnaDataSolutions.com
RDBMS
 Relational Database Management Systems
 Software that provides Users and
Applications, with processes to: Define,
Create, Manipulate and Share (Relational)
Databases
User Applications
RDBMS Server
…

MagnaDataSolutions.com
Relational Databases
 Database > Tables > Rows > Columns
1
1..*
1
1
0..*
1
0..*
0..*
 ERD: display entities
and how they are
related
 Primary Keys (PK):
Uniquely identifies
each record in a table
 Foreign Keys (FK):
refers to the Primary
Key in another table

MagnaDataSolutions.com
Introduction to SQL

MagnaDataSolutions.com
About the SQL Language
 Structured Query Language
 SQL / SEQUEL (Structured English Query Language)
 Interact with Relational Databases
 Comes from Relational Algebra & Calculus.
Codd, Chamberlin & Boyce.
SQL history by Chamberlin, here: https://ieeexplore.ieee.org/document/6359709
 Declarative Language vs Procedural/imperative language
 SQL Standard defined by ANSI (American National Standards Institute)
 Vendors variations and extensions.

MagnaDataSolutions.com
Extensions to SQL Language
Add Procedural Programming Language Functionality (Functions,
Cursors, arrays, loops, Control of Flows, etc)
Oracle PL/SQL Procedural Language/SQL
Microsoft SQL Server T-SQL Transact-SQL
Informix SPL Stored Procedural Language
MySQL SQL/PSM SQL/Persistent Stored Module
PostgreSQL PL/pgSQL Procedural Language/PostgreSQL SQL
SAP R3 ABAP Advance Business Application Programming
MariaDB SQL/PSM SQL/Persistent Stored Module

MagnaDataSolutions.com
Language Classifications
SQL
DDL
Create, Alter,
Drop, Rename
DML
Select, Insert,
Update, Delete
DCL
Grant,
Revoke, Deny
RDBMS Server

MagnaDataSolutions.com
DML SYNTAX

MagnaDataSolutions.com
DML - Syntax
SELECT Column1, Column2, … FROM Table1
SELECT Column1, Column2, … FROM Table1 WHERE Condition
INSERT INTO Table1 (Column1,Column2,…) VALUES(Value1,Value2,…)
UPDATE Table1 SET Column1=Value1, Column2=Value2,…
UPDATE Table1 SET Column1=Value1, Column2=Value2,… WHERE Condition
DELETE FROM Table1
DELETE FROM Table1 WHERE Condition

MagnaDataSolutions.com
DML – Syntax - Examples
• SELECT FirstName, LastName, email, DoB, FROM Customer;
• UPDATE Customer SET LastName=‘Smith’ WHERE CustomerID=123;
• INSERT INTO Customer(FirstName, LastName, email)
VALUES (‘Jane’, ’Doe’, ’Jdoe@gmail.com’);
• DELETE FROM Customer WHERE CustomerID = 123;

MagnaDataSolutions.com
Interaction Example
SQL Statement
SELECT * FROM [Orders]
User/App
Microsoft
SQL Server
1
2 3
4

MagnaDataSolutions.com
Let’s Explore SELECT
DML

MagnaDataSolutions.com
SELECT
 Selects Data and Returns a Result-set. (result table)
 * Brings all fields
 Specify Columns
SELECT * FROM Table1;
SELECT Column1, Column2, …, ColumnN FROM Table1;

MagnaDataSolutions.com
ORDER BY
 Sorts the Result_set by the Column(s) specified.
 ASC, DESC
SELECT Column1, Column2
FROM Table1
ORDER BY Column1 DESC;

MagnaDataSolutions.com
WHERE Clause
SELECT Column1, Column2
FROM Table1
WHERE Condition;
Conditionals:
 Boolean operators/Logical Operators AND, OR, NOT
 Comparison operators:
 =,<>,<=,>. Some DBs inequality: !=,^=,<>
 ANY/SOME
 EXISTS
 LIKE
 BETWEEN
 IS NULL

MagnaDataSolutions.com
NULL values
 Represents “Nothingness”. It is not a Value. It is an Empty field
 Origin: Value not entered/recorded
 May affect results (Example with AVG)
 Used with operators IS/NOT: IS NULL, IS NOT NULL

MagnaDataSolutions.com
Aggregations
Function Description
COUNT() Counts elements in a column. COUNT (*) counts tuples.
SUM() Returns the Summarization of all values in a column.
AVG() Returns the Average from values in a column.
MAX() Returns the Maximum value in a column.
MIN() Returns the Minimum value in a column

MagnaDataSolutions.com
GROUP BY
Create Subgroups of Tuples
SELECT Column1, SUM(Column2)
FROM Table1
GROUP BY Column1;

MagnaDataSolutions.com
HAVING
 HAVING clause: contains conditions on aggregates
 Specifies a search condition for Groups
SELECT Column1, SUM(Column2)
FROM Table1
GROUP BY Column1
HAVING SUM(Column2) >10000;

MagnaDataSolutions.com
Syntax Evaluation Order (Ms SQL Server)
1
2
3
4
5
6

MagnaDataSolutions.com
Types of JOINS
Natural Join,
INNER Join,
Join
Left Outer Join Right Outer Join
Full Outer Join

MagnaDataSolutions.com
Inner Join
SELECT *
FROM Table1 T1 INNER JOIN
Table2 T2 ON (T1.ID=T2.ID)

MagnaDataSolutions.com
Left Outer Join
SELECT *
FROM Table1 T1 LEFT JOIN
Table2 T2 ON (T1.ID=T2.ID)

MagnaDataSolutions.com
Right Outer Join
SELECT *
FROM Table1 T1 RIGHT JOIN
Table2 T2 ON (T1.ID=T2.ID)

MagnaDataSolutions.com
Full Outer Join
SELECT *
FROM Table1 T1 FULL OUTER JOIN
Table2 T2 ON (T1.ID=T2.ID)

MagnaDataSolutions.com
Oracle
SQL

MagnaDataSolutions.com
Resources
 Practice website:
https://www.w3schools.com/sql/trysql.asp?filename=trysql_select_all
 Oracle:
https://docs.oracle.com/en/database/oracle/oracle-
database/19/sqlrf/Introduction-to-Oracle-SQL.html
 PostgreSQL:
https://www.postgresql.org/docs/current/sql.html
 Ms SQL Server:
https://learn.microsoft.com/en-us/training/paths/get-started-querying-with-
transact-sql/
 MySQL:
https://dev.mysql.com/doc/refman/8.0/en/sql-statements.html
 IBM DB2:
https://www.ibm.com/docs/en/db2-for-zos/11?topic=db2-sql

MagnaDataSolutions.com
THANK YOU!
Connect to me at: Cecilia@MagnaDataSolutions.com
/CeBrusa
@CeBrusa
@MagnaDatainc
@MagnaDatainc
/company/magnadatainc
https://magnadatainc.com
Presentation:
www.MagnaDataSolutions.com/intro-to-sql-language