[SQL] - Comments(SQL 주석)

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기본적으로 실행문의 결과값은 사이트에 직접가서 실행해보고 결과를 확인하는것이 좋습니다.

결과값이 너무 큰 경우 일부만 발췌하거나 기록하지 않았습니다.

 

 

SQL Comments

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주석은 SQL 문의 섹션을 설명하거나 SQL 문의 실행을 막는 데 사용됩니다.

참고 :이 장의 예제는 Firefox 및 Microsoft Edge에서 작동하지 않습니다! 

주석은 Microsoft Access 데이터베이스에서 지원되지 않습니다.
Firefox와 Microsoft Edge는 예제에서 Microsoft Access 데이터베이스를 사용하고 있습니다.

 

Single Line Comments

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한 줄 주석은 -로 시작합니다.

 -와 행 끝 사이의 모든 텍스트는 무시됩니다 (실행되지 않습니다).

다음 예제는 한 줄 주석을 설명으로 사용합니다.

 

Example

--Select all: 

SELECT * FROM Customers;

w3schools.com 에서 직접 실행해볼것

Result:(일부만 발췌)

Number of Records: 154

CustomerID	CustomerName	ContactName	Address	City	PostalCode	Country
2	Ana Trujillo Emparedados y helados	Juan	Avda. de la Constitución 2222	México D.F.	05021	Mexico
3	Antonio Moreno Taquería	Juan	Mataderos 2312	México D.F.	05023	Mexico
4	Around the Horn	Juan	120 Hanover Sq.	London	WA1 1DP	UK
5	Berglunds snabbköp	Juan	Berguvsvägen 8	Luleå	S-958 22	Sweden
6	Blauer See Delikatessen	Juan	Forsterstr. 57	Mannheim	68306	Germany
7	Blondel père et fils	Juan	24, place Kléber	Strasbourg	67000	France
8	Bólido Comidas preparadas	Juan	C/ Araquil, 67	Madrid	28023	Spain
9	Bon app’	Juan	12, rue des Bouchers	Marseille	13008	France

총 154개의 Record가 있음

 

 

다음 예제에서는 한 줄 주석을 사용하여 줄 끝을 무시합니다:

Example

SELECT * FROM Customers -- WHERE City='Berlin';

w3schools.com 에서 직접 실행해볼것

Result(일부만 발췌):

Number of Records: 154

CustomerID	CustomerName	ContactName	Address	City	PostalCode	Country
2	Ana Trujillo Emparedados y helados	Juan	Avda. de la Constitución 2222	México D.F.	05021	Mexico
3	Antonio Moreno Taquería	Juan	Mataderos 2312	México D.F.	05023	Mexico
4	Around the Horn	Juan	120 Hanover Sq.	London	WA1 1DP	UK
5	Berglunds snabbköp	Juan	Berguvsvägen 8	Luleå	S-958 22	Sweden
6	Blauer See Delikatessen	Juan	Forsterstr. 57	Mannheim	68306	Germany
7	Blondel père et fils	Juan	24, place Kléber	Strasbourg	67000	France
8	Bólido Comidas preparadas	Juan	C/ Araquil, 67	Madrid	28023	Spain
9	Bon app’	Juan	12, rue des Bouchers	Marseille	13008	France

총 154개의 Record가 있음

 

 

다음 예제에서는 한 줄 주석을 사용하여 문을 무시합니다:

Example

--SELECT * FROM Customers; 

SELECT * FROM Products;

w3schools.com 에서 직접 실행해볼것

Result(일부만 발췌):

Number of Records: 77

ProductID	ProductName	SupplierID	CategoryID	Unit	Price
1	Chais	1	1	10 boxes x 20 bags	18
2	Chang	1	1	24 - 12 oz bottles	19
3	Aniseed Syrup	1	2	12 - 550 ml bottles	10
4	Chef Anton’s Cajun Seasoning	2	2	48 - 6 oz jars	22
5	Chef Anton’s Gumbo Mix	2	2	36 boxes	21.35
6	Grandma’s Boysenberry Spread	3	2	12 - 8 oz jars	25
7	Uncle Bob’s Organic Dried Pears	3	7	12 - 1 lb pkgs.	30
8	Northwoods Cranberry Sauce	3	2	12 - 12 oz jars	40
9	Mishi Kobe Niku	4	6	18 - 500 g pkgs.	97
10	Ikura	4	8	12 - 200 ml jars	31
11	Queso Cabrales	5	4	1 kg pkg.	21

총 77개의 Record가 있음

 

Multi-line Comments

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여러 줄 주석은 / *로 시작하고 */로 끝납니다.

/ *와 */ 사이의 모든 텍스트는 무시됩니다.

다음 예제에서는 설명을 위해 여러 줄 주석을 사용합니다:

 

Example

/*Select all the columns of all the records in the Customers table:*/ 

SELECT * FROM Customers;

w3schools.com 에서 직접 실행해볼것

Result(일부만 발췌):

Number of Records: 154

CustomerID	CustomerName	ContactName	Address	City	PostalCode	Country
2	Ana Trujillo Emparedados y helados	Juan	Avda. de la Constitución 2222	México D.F.	05021	Mexico
3	Antonio Moreno Taquería	Juan	Mataderos 2312	México D.F.	05023	Mexico
4	Around the Horn	Juan	120 Hanover Sq.	London	WA1 1DP	UK
5	Berglunds snabbköp	Juan	Berguvsvägen 8	Luleå	S-958 22	Sweden
6	Blauer See Delikatessen	Juan	Forsterstr. 57	Mannheim	68306	Germany
7	Blondel père et fils	Juan	24, place Kléber	Strasbourg	67000	France
8	Bólido Comidas preparadas	Juan	C/ Araquil, 67	Madrid	28023	Spain
9	Bon app’	Juan	12, rue des Bouchers	Marseille	13008	France

총 154개의 Record가 있음

 

다음 예제에서는 여러 줄 주석을 사용하여 여러 줄을 무시합니다:

Example

/*SELECT * FROM Customers;

SELECT * FROM Products;

SELECT * FROM Orders;

SELECT * FROM Categories;*/ 

SELECT * FROM Suppliers;

w3schools.com 에서 직접 실행해볼것

Result:

Number of Records: 29

SupplierID	SupplierName	ContactName	Address	City	PostalCode	Country	Phone
1	Exotic Liquid	Charlotte Cooper	49 Gilbert St.	Londona	EC1 4SD	UK	(171) 555-2222
2	New Orleans Cajun Delights	Shelley Burke	P.O. Box 78934	New Orleans	70117	USA	(100) 555-4822
3	Grandma Kelly’s Homestead	Regina Murphy	707 Oxford Rd.	Ann Arbor	48104	USA	(313) 555-5735
4	Tokyo Traders	Yoshi Nagase	9-8 Sekimai Musashino-shi	Tokyo	100	Japan	(03) 3555-5011
5	Cooperativa de Quesos ‘Las Cabras’	Antonio del Valle Saavedra	Calle del Rosal 4	Oviedo	33007	Spain	(98) 598 76 54
6	Mayumi’s	Mayumi Ohno	92 Setsuko Chuo-ku	Osaka	545	Japan	(06) 431-7877
7	Pavlova, Ltd.	Ian Devling	74 Rose St. Moonie Ponds	Melbourne	3058	Australia	(03) 444-2343
8	Specialty Biscuits, Ltd.	Peter Wilson	29 King’s Way	Manchester	M14 GSD	UK	(161) 555-4448
9	PB Knäckebröd AB	Lars Peterson	Kaloadagatan 13	Göteborg	S-345 67	Sweden	031-987 65 43
10	Refrescos Americanas LTDA	Carlos Diaz	Av. das Americanas 12.890	São Paulo	5442	Brazil	(11) 555 4640
11	Heli Süßwaren GmbH & Co. KG	Petra Winkler	Tiergartenstraße 5	Berlin	10785	Germany	(010) 9984510
12	Plutzer Lebensmittelgroßmärkte AG	Martin Bein	Bogenallee 51	Frankfurt	60439	Germany	(069) 992755
13	Nord-Ost-Fisch Handelsgesellschaft mbH	Sven Petersen	Frahmredder 112a	Cuxhaven	27478	Germany	(04721) 8713
14	Formaggi Fortini s.r.l.	Elio Rossi	Viale Dante, 75	Ravenna	48100	Italy	(0544) 60323
15	Norske Meierier	Beate Vileid	Hatlevegen 5	Sandvika	1320	Norway	(0)2-953010
16	Bigfoot Breweries	Cheryl Saylor	3400 - 8th Avenue Suite 210	Bend	97101	USA	(503) 555-9931
17	Svensk Sjöföda AB	Michael Björn	Brovallavägen 231	Stockholm	S-123 45	Sweden	08-123 45 67
18	Aux joyeux ecclésiastiques	Guylène Nodier	203, Rue des Francs-Bourgeois	Paris	75004	France	(1) 03.83.00.68
19	New England Seafood Cannery	Robb Merchant	Order Processing Dept. 2100 Paul Revere Blvd.	Boston	02134	USA	(617) 555-3267
20	Leka Trading	Chandra Leka	471 Serangoon Loop, Suite #402	Singapore	0512	Singapore	555-8787
21	Lyngbysild	Niels Petersen	Lyngbysild Fiskebakken 10	Lyngby	2800	Denmark	43844108
22	Zaanse Snoepfabriek	Dirk Luchte	Verkoop Rijnweg 22	Zaandam	9999 ZZ	Netherlands	(12345) 1212
23	Karkki Oy	Anne Heikkonen	Valtakatu 12	Lappeenranta	53120	Finland	(953) 10956
24	G’day, Mate	Wendy Mackenzie	170 Prince Edward Parade Hunter’s Hill	Sydney	2042	Australia	(02) 555-5914
25	Ma Maison	Jean-Guy Lauzon	2960 Rue St. Laurent	Montréal	H1J 1C3	Canada	(514) 555-9022
26	Pasta Buttini s.r.l.	Giovanni Giudici	Via dei Gelsomini, 153	Salerno	84100	Italy	(089) 6547665
27	Escargots Nouveaux	Marie Delamare	22, rue H. Voiron	Montceau	71300	France	85.57.00.07
28	Gai pâturage	Eliane Noz	Bat. B 3, rue des Alpes	Annecy	74000	France	38.76.98.06
29	Forêts d’érables	Chantal Goulet	148 rue Chasseur	Ste-Hyacinthe	J2S 7S8	Canada	(514) 555-2955

 

명령문의 일부만 무시하려면 / * * / 주석도 사용하십시오.

다음 예제에서는 주석을 사용하여 행의 일부를 무시합니다:

Example

SELECT CustomerName, /*City,*/ Country FROM Customers;

w3schools.com 에서 직접 실행해볼것

Result(일부만 발췌):

Number of Records: 154

CustomerName	Country
Ana Trujillo Emparedados y helados	Mexico
Antonio Moreno Taquería	Mexico
Around the Horn	UK
Berglunds snabbköp	Sweden
Blauer See Delikatessen	Germany
Blondel père et fils	France
Bólido Comidas preparadas	Spain
Bon app’	France
Bottom-Dollar Marketse	Canada
B’s Beverages	UK
Cactus Comidas para llevar	Argentina

총 154개의 Record가 있음

 

 

다음 예제에서는 주석을 사용하여 명령문의 일부를 무시합니다:

Example

SELECT * FROM Customers WHERE (CustomerName LIKE 'L%' 

OR CustomerName LIKE 'R%' /*OR CustomerName LIKE 'S%'

OR CustomerName LIKE 'T%'*/ OR CustomerName LIKE 'W%') 

AND Country='USA' 

ORDER BY CustomerName;

w3schools.com 에서 직접 실행해볼것

Result:

Number of Records: 5

CustomerID	CustomerName	ContactName	Address	City	PostalCode	Country
43	Lazy K Kountry Store	Juan	12 Orchestra Terrace	Walla Walla	99362	USA
45	Let’s Stop N Shop	Juan	87 Polk St. Suite 5	San Francisco	94117	USA
48	Lonesome Pine Restaurant	Juan	89 Chiaroscuro Rd.	Portland	97219	USA
65	Rattlesnake Canyon Grocery	Juan	2817 Milton Dr.	Albuquerque	87110	USA
89	White Clover Markets	Juan	305 - 14th Ave. S. Suite 3B	Seattle	98128	USA