This is a PowerPoint I made on how to Use SQL. Hopefully it is helpful.

1. How to: SQL
By: Sam Loch

2. Goal
 To retrieve data from and insert data into a relational database
Customer
CustomerID
FirstName
LastName
Email
Phone
Address
Order
OrderID
CustomerID
OrderDate
ShippingInstruction
s
Order-Product
OrderProductID
OrderID
ProductID
Quantity
Product
ProductID
ProductName
Price
InventoryLevel

3. How to Accomplish Our Goal
 Structured Query Language (SQL)
 Using SQL we can
 Retrieve data from a database
 Insert data into a database
 Update data in a database
 Delete data in a database
 Add and delete tables form a database
 Combine tables in a database

4. Creating a Database
 Define the database
 Create tables
 Define columns within these tables and choose their data types
 Each table needs a Primary Key
 Some tables will need Foreign Key’s to communicate with other tables in the database

5. Creating a Database (2)
 CREATE statements
 These can be used to create a table within a database
 Example:
CREATE TABLE db_name.table_name (
ColumnName1 datatype NOT NULL,
ColumnName2 datatype NULL,
PRIMARY KEY (KeyName));
Text Description
NULL/NOT
NULL
Defines whether the field can be
empty (NULL) or whether it cannot
(NOT NULL)
Primary Key’s cannot be NULL
datatype The data-type of the column.

6. Creating a Database (3)
 Another Example:
CREATE TABLE salesdb.Order (
OrderID INT NOT NULL,
CustomerID INT NOT NULL,
OrderDate DATE NULL,
ShippingInstructions VARCHAR(45) NULL,
PRIMARY KEY (OrderID));
Order
OrderID
CustomerID
OrderDate
ShippingInstruction
s

7. Data Types
 Each column can contain a different type of data
 The data type of each column must be specified when it is created
 A few data types:
Data type Description Examples
INT Integer 4, 62, -20
DECIMAL(p,s) Decimal. Example: decimal(6,3) is a
number that has 3 digits after the
decimal and 6 digits total (123.456)
6.5, 0.9987, 123.456
VARCHAR(x) String of any characters with a
maximum length of x
‘Howdy’,
‘She sells seashells by
the sea shore’
DATETIME,
DATE
Date and time, or just Date '2017-05-03 20:43:00',
'2017-05-03'
BOOLEAN Boolean value 0,1

8. Foreign Keys
 The Foreign Key in one table connects that table to a Primary key in another table.
CREATE TABLE salesdb.`Order-Product` (
OrderProductID INT NOT NULL,
OrderID INT NULL,
ProductID INT NULL,
Quantity INT NULL,
PRIMARY KEY (OrderProductID),
FOREIGN KEY (OrderID) REFERENCES salesdb.Order(OrderID)
FOREIGN KEY (ProductID) REFERENCES salesdb.Product(ProductID)
Product
ProductID
ProductName
Price
InventoryLevel
Order-Product
OrderProductID
OrderID
ProductID
Quantity
ProductID is a foreign key in the
Order-Product table, and the
primary key in the Product table.

9. Deleting Tables
 DROP TABLE db_name.table_name;
 EX: DROP TABLE salesdb.Product;

10. Altering the Data in a Table
Adding a column:
ALTER TABLE db_name.table_name
ADD COLUMN column_name datatype (NULL or NOT NULL);
Deleting a column:
ALTER TABLE db_name.table_name
DROP COLUMN column_name;
Changing a column:
ALTER TABLE db_name.table_name
CHANGE COLUMN old_column_name
new_column_name datatype (NULL or NOT NULL);

11. Altering the Data in a Table (2)
 Examples:
ALTER TABLE salesdb.Product
ADD COLUMN Color VARCHAR(10) NULL;
ALTER TABLE salesdb.Product
DROP COLUMN Color;
ALTER TABLE salesdb.Product
CHANGE COLUMN Color
Version VARCHAR(20) NULL;
Adds “Color” column
to Product table
Changes “Color”
column from Product
table to “Version” and
changes character
limit from 10 to 20
Deletes “Color” column
to Product table

12. Adding a Row to a Table
INSERT INTO db_name.table_name
(ColumnName1, ColumnName2, ColumnName3)
VALUES (Value1, Value2, Value3);
 Example:
INSERT INTO salesdb.Customer
(CustomerID, FirstName, LastName, Email, Phone, Address)
VALUES (2003, ‘Kit’, ‘Fisto’, ‘KFisto@Gmail .com’, 717.555.1234, ‘560 Lois Lane
Pittsburgh, PA’)
CustomerID FirstName LastName Email Phone Address
1999 Johnny Bravo Jbravo@gmail.com 215.555.5678 1624 N. 18th Street Philadelphia, PA
2000 Dwight Shrute BeetBoi@Hotmail.co
m
717.555.5555 12 Farm Street Scranton, PA
2001 Patches O‘Houlihan Dballislife@gmail.com 717.555.0000 34 Legend Lane Lancaster, PA
2002 Eric Foreman Eforeman@yahoo.com 215.555.9876 1919 S. 19th Street Philadelphia, PA
2003 Kit Fisto Kfisto@gmail.com 717.555.123
4
560 Lois Lane Pittsburgh, PA

13. Changing a Row
UPDATE db_name.table_name
SET ColumnName1 = Value1, ColumnName2 = Value2
WHERE condition;
 Example:
UPDATE salesdb.Product
SET ProductName = ‘Shake Weight’, Price = 99.99
WHERE ProductID = 1341;
ProductID ProductName Price
1341 Shake Weight 99.99
1342 The Claw 29.99
1343 SHAM WOW 4.99
The Price of the Shake
Weight was changed to
99.99

14. Deleting a Row
DELETE FROM db_name.table_name
WHERE condition;
 Example:
DELETE FROM salesdb.Product
WHERE ProductID = 1738;

15. Retrieving Data From a Database
 SELECT statements
 SELECT statements are used to retrieve data from a database
 EX:
SELECT column_name(s)
FROM db_name.table_name;

16. SELECT statements
 If you had a customer table and wanted to see the first and last names of all
of the customers you would type:
SELECT FirstName, LastName
FROM salesdb.Customer
 This would return:
CustomerID FirstName LastName Email Phone Address
1999 Johnny Bravo Jbravo@gmail.com 215.555.5678 1624 N. 18th Street Philadelphia, PA
2000 Dwight Shrute BeetBoi@Hotmail.co
m
717.555.5555 12 Farm Street Scranton, PA
2001 Patches O‘Houlihan Dballislife@gmail.com 717.555.0000 34 Legend Lane Lancaster, PA
2002 Eric Foreman Eforeman@yahoo.com 215.555.9876 1919 S. 19th Street Philadelphia, PA
2003 Kit Fisto Kfisto@gmail.com 717.555.1234 560 Lois Lane Pittsburgh, PA
FirstName LastName
Johnny Bravo
Dwight Shrute
Patches O‘Houlihan
Eric Foreman
Kit Fisto

17. Retrieving All Columns in a Table
SELECT * FROM salesdb.Customer
CustomerID FirstName LastName Email Phone Address
1999 Johnny Bravo Jbravo@gmail.com 215.555.5678 1624 N. 18th Street Philadelphia, PA
2000 Dwight Shrute BeetBoi@Hotmail.co
m
717.555.5555 12 Farm Street Scranton, PA
2001 Patches O‘Houlihan Dballislife@gmail.com 717.555.0000 34 Legend Lane Lancaster, PA
2002 Eric Foreman Eforeman@yahoo.com 215.555.9876 1919 S. 19th Street Philadelphia, PA
2003 Kit Fisto Kfisto@gmail.com 717.555.1234 560 Lois Lane Pittsburgh, PA

18. Retrieving Values
 To retrieve only unique values:
SELECT DISTINCT Price
FROM salesdb.Product;
 To retrieve certain records only
SELECT * FROM salesdb.Product WHERE Price = 99.99;
SELECT * FROM salesdb.Product WHERE Price > 5;

19. WHERE Clause
 The following is a list of operators that can be used in the WHERE Clause:
Operator Description
= Equal to
> Greater than
>= Greater than or equal to
< Less than
<= Less than or equal to
<> Not equal to

20. Sorting Results of a Select Statement
SELECT * FROM salesdb.Customer
WHERE CustomerID >= 2000
ORDER BY FirstName;
CustomerID FirstName LastName Email Phone Address
2000 Dwight Shrute BeetBoi@Hotmail.co
m
717.555.5555 12 Farm Street Scranton, PA
2002 Eric Foreman Eforeman@yahoo.com 215.555.9876 1919 S. 19th Street Philadelphia, PA
2003 Kit Fisto Kfisto@gmail.com 717.555.1234 560 Lois Lane Pittsburgh, PA
2001 Patches O‘Houlihan Dballislife@gmail.com 717.555.0000 34 Legend Lane Lancaster, PA

21. ORDER BY Ascending (ASC) and
Descending (DESC)
SELECT * FROM salesdb.Product
ORDER BY Price ASC;
SELECT * FROM salesdb.Product
ORDER BY Price DESC;
ProductID ProductName Price
1341 Shake Weight 99.99
1342 The Claw 29.99
1343 SHAM WOW 4.99
ProductID ProductName Price
1343 Shake Weight 4.99
1342 The Claw 29.99
1341 SHAM WOW 99.99

22. Other SQL Functions
 COUNT() – Returns the number of rows
 MAX() – Returns the largest value
 MIN() – Returns the smallest value
 SUM() – Returns the sum
 AVG() – Returns the average value

23. Fun With Functions
SELECT MAX(Price) FROM salesdb.Product;
SELECT COUNT(ProductID) FROM salesdb.Product;
SELECT MIN(Price) FROM salesdb.Product;
SELECT SUM(Price) FROM salesdb.Product;
SELECT AVG(Price) FROM salesdb.Product;
ProductID ProductName Price
1341 Shake Weight 99.99
1342 The Claw 29.99
1343 SHAM WOW 4.99
Price
99.99
3
Price
4.99
Price
134.97
Price
44.99

24. SELECTing From Multiple Tables
 To SELECT from multiple tables you must join the tables with WHERE
 Example:
SELECT * FROM salesdb.Customer, salesdb.Order
WHERE Customer.CustomerID = Order.CustomerID;
 This Returns:
Custom
er.Cust
omerID
First
Nam
e
Last
Nam
e
Email Phone Address OrderID OrderDate Order.CustomerID
2000 Dwig
ht
Shru
te
BeetBoi@H
otmail.com
717.555.5
555
12 Farm Street Scranton, PA 102 2017-4-15 1002
2002 Eric Fore
man
Eforeman@
yahoo.com
215.555.9
876
1919 S. 19th Street
Philadelphia, PA
103 2017-4-25 1003
2003 Kit Fisto Kfisto@gm
ail.com
717.555.1
234
560 Lois Lane Pittsburgh, PA 104 2017-4-30 1004
2001 Patc
hes
O‘Ho
uliha
n
Dballislife
@gmail.co
m
717.555.0
000
34 Legend Lane Lancaster, PA 105 2017-5-3 1005

25. JOIN Syntax
SELECT * FROM salesdb.Customer, salesdb.Order
WHERE Customer.CustomerID = Order.CustomerID;
SELECT * Return all the columns from both
tables
FROM salesdb.Customer,
salesdb.Order
The two tables to be joined
WHERE Customer.CustomerID
= Order.CustomerID
Only choose records where the
CustomerID exists in both tables

26. Summary
 Use CREATE statements to create a table
 Use DROP TABLE to delete a table
 Use ALTER TABLE to change the data in a table
 ADD COLUMN
 DROP COLUMN
 CHANGE COLUMN
 Use INSERT INTO to add a row
 Use UPDATE and SET to change
a row
 Use DELETE FROM to delete a
row
Data type Description Examples
INT Integer 4, 62, -20
DECIMAL(p,s) Decimal. Example: decimal(6,3) is a
number that has 3 digits after the
decimal and 6 digits total (123.456)
6.5, 0.9987, 123.456
VARCHAR(x) String of any characters with a
maximum length of x
‘Howdy’,
‘She sells seashells by
the sea shore’
DATETIME,
DATE
Date and time, or just Date '2017-05-03 20:43:00',
'2017-05-03'
BOOLEAN Boolean value 0,1
Text Description
NULL/NOT
NULL
Defines whether the field can be
empty (NULL) or whether it cannot
(NOT NULL)
Primary Key’s cannot be NULL
datatype The data-type of the column.

27. Summary(2)
 Use SELECT statements to retrieve data from a database
 SELECT * selects all data from
 COUNT() – Returns the number of rows
 MAX() – Returns the largest value
 MIN() – Returns the smallest value
 SUM() – Returns the sum
 AVG() – Returns the average value