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SQL•SQL Tutorial

SQL EXISTS Operator

Flash cards

Review the key moves

1/4

Core idea

What is the main idea behind SQL EXISTS Operator?

Lesson checks

Practice each idea before moving on

Short Mimo-style checks built from this lesson's code, terms, and sequence.

1Quick choice

Which statement best captures the main point of this lesson?

2Fill blank

Complete the missing token from the example code.

___(s)

3Order

Put the learning moves in the order that makes the concept easiest to apply.

The EXISTS operator evaluates to TRUE if the subquery returns at least one row, and FALSE otherwise.

The EXISTS operator is used in a WHERE clause to check whether a subquery returns any rows.

The SQL EXISTS Operator

The EXISTS operator is used in a WHERE clause to check whether a subquery returns any rows.

The EXISTS operator evaluates to TRUE if the subquery returns at least one row, and FALSE otherwise.

EXISTS Syntax

SELECT
column_name(s)
 FROM
table_name
WHERE EXISTS (
subquery
);

Demo Database

Below is a selection from the "Products" table in the Northwind sample database:

ProductID	ProductName	SupplierID	CategoryID	Unit	Price
1	Chais	1	1	10 boxes x 20 bags	18.00
2	Chang	1	1	24 - 12 oz bottles	19.00
3	Aniseed Syrup	1	2	12 - 550 ml bottles	10.00
4	Chef Anton's Cajun Seasoning	2	2	48 - 6 oz jars	22.00
5	Chef Anton's Gumbo Mix	2	2	36 boxes	21.35

And a selection from the "Suppliers" table:

SupplierID	SupplierName	ContactName	Address	City	PostalCode	Country
1	Exotic Liquid	Charlotte Cooper	49 Gilbert St.	London	EC1 4SD	UK
2	New Orleans Cajun Delights	Shelley Burke	P.O. Box 78934	New Orleans	70117	USA
3	Grandma Kelly's Homestead	Regina Murphy	707 Oxford Rd.	Ann Arbor	48104	USA
4	Tokyo Traders	Yoshi Nagase	9-8 Sekimai Musashino-shi	Tokyo	100	Japan

SQL HAVING Clause

SQL ANY Operator

Loading lesson path

SQL•SQL Tutorial

SQL EXISTS Operator

Flash cards

Review the key moves

1/4

Core idea

What is the main idea behind SQL EXISTS Operator?

Lesson checks

Practice each idea before moving on

Short Mimo-style checks built from this lesson's code, terms, and sequence.

1Quick choice

Which statement best captures the main point of this lesson?

2Fill blank

Complete the missing token from the example code.

___(s)

3Order

Put the learning moves in the order that makes the concept easiest to apply.

The EXISTS operator evaluates to TRUE if the subquery returns at least one row, and FALSE otherwise.

The EXISTS operator is used in a WHERE clause to check whether a subquery returns any rows.

The SQL EXISTS Operator

The EXISTS operator is used in a WHERE clause to check whether a subquery returns any rows.

The EXISTS operator evaluates to TRUE if the subquery returns at least one row, and FALSE otherwise.

EXISTS Syntax

SELECT
column_name(s)
 FROM
table_name
WHERE EXISTS (
subquery
);

Demo Database

Below is a selection from the "Products" table in the Northwind sample database:

ProductID	ProductName	SupplierID	CategoryID	Unit	Price
1	Chais	1	1	10 boxes x 20 bags	18.00
2	Chang	1	1	24 - 12 oz bottles	19.00
3	Aniseed Syrup	1	2	12 - 550 ml bottles	10.00
4	Chef Anton's Cajun Seasoning	2	2	48 - 6 oz jars	22.00
5	Chef Anton's Gumbo Mix	2	2	36 boxes	21.35

And a selection from the "Suppliers" table:

SupplierID	SupplierName	ContactName	Address	City	PostalCode	Country
1	Exotic Liquid	Charlotte Cooper	49 Gilbert St.	London	EC1 4SD	UK
2	New Orleans Cajun Delights	Shelley Burke	P.O. Box 78934	New Orleans	70117	USA
3	Grandma Kelly's Homestead	Regina Murphy	707 Oxford Rd.	Ann Arbor	48104	USA
4	Tokyo Traders	Yoshi Nagase	9-8 Sekimai Musashino-shi	Tokyo	100	Japan

SQL HAVING Clause

SQL ANY Operator