Beginning SQL

More documents

Recommendations

Info

Chapter 8 In the query, the Category and Films tables are joined with an inner join based on CategoryId. The query then restricts which films form the results by use of a subquery in the WHERE clause. The subquery returns the lowest-priced DVD for a particular category. The category returned by the subquery is linked to the CategoryId of the Category table in the outer query. Note that Films.CategoryId inside the subquery refers to the Films table in that subquery, not to the Films table outside the subquery. Then in the WHERE clause of the outer query, Films.DVDPrice is compared with the minimum price for that category, which is returned by the subquery. If there’s a match, then clearly the film’s price matches the value of the minimum price. The results are as follows: Category FilmName DVDPrice Thriller The Maltese Poodle 2.99 Romance On Golden Puddle 12.99 Horror One Flew over the Crow’s Nest 8.95 War Planet of the Japes 12.99 Sci-fi Soylent Yellow 12.99 Historical The Good, the Bad, and the Facially Challenged 8.95 Now that you have a good handle on how subqueries function and how you can include them in SELECT lists and WHERE clauses, you can move on to more complex subqueries that employ various operators, including IN, ANY, SOME, and ALL. Operators in Subqueries So far, all the subqueries you’ve seen have been scalar subqueries — that is, queries that only return only one row. If more than one row is returned, you end up with an error. In this and the following sections, you learn about operators that allow you to make comparisons against a multirecord results set. Revisiting the IN Operator 242 You first learned about the IN operator in Chapter 3. Just to recap, the IN operator allows you to specify that you want to match one item from any of those in a list of items. For example, the following <strong>SQL</strong> finds all the members who were born in 1967, 1992, or 1937: SELECT FirstName, LastName, YEAR(DateOfBirth) FROM MemberDetails WHERE YEAR(DateOfBirth) IN (1967, 1992, 1937); Note that this code, and any code that contains the YEAR() function, won’t work in Oracle because it doesn’t support the YEAR() function.
Page 2:
Beginning SQL Paul Wilton and John
Page 10:
Beginning SQL Paul Wilton and John
Page 14:
About the Authors Paul Wilton After
Page 18:
Paul Wilton: With lots of love to m
Page 24:
Contents x Selecting Correct Data T
Page 28:
Contents xii Re-examining NULL 180
Page 32:
Contents Chapter 11: Transactions 3
Page 36:
Contents xvi How Do You Do It? 357
Page 42:
Introduction Data, data, data! Data
Page 46:
By the time you’ve completed Chap
Page 50:
Once you download the code, just de
Page 54:
1 Introduction to SQL A nice, gentl
Page 58:
Figure 1-1 Why and When to Use a Da
Page 62:
Databases are great at dealing with
Page 66:
The SQL language is actually fairly
Page 70:
you wish, and the database system d
Page 74:
A keyword is a word that has some m
Page 78:
Introduction to SQL A perfectly val
Page 82:
Data Type Description Storage Used
Page 86:
The char and varchar data types use
Page 90:
Most RDBMSs handle the most common
Page 94:
To add a new column, use the basic
Page 98:
Now that you know what you want to
Page 102:
❑ Meeting date 2 ❑ Location 2
Page 106:
Generally speaking, picking a data
Page 110:
example, the MemberId field links t
Page 114:
Depending on which RDBMS you’re u
Page 118:
The FilmCategory table is very smal
Page 122:
2 Entering Information The last cha
Page 126:
like this: INSERT INTO Category VAL
Page 130:
Inserting Data into the Case Study
Page 134:
The WHERE Clause So far you’ve se
Page 138:
Try It Out Using Logical Operators
Page 142:
Exercises 1. Three new members have
Page 148:
Chapter 3 54 MemberId FirstName 1 K
Page 152:
Chapter 3 The results are as follow
Page 156:
Chapter 3 The results to this query
Page 160:
Chapter 3 FavCategory (CategoryId,
Page 164:
Chapter 3 Logical Operators and Ope
Page 168:
Chapter 3 The statement returns the
Page 172:
Chapter 3 NOT Operator Examples thu
Page 176:
Chapter 3 2. Using the following SQ
Page 180:
Chapter 3 When you execute the quer
Page 184:
Chapter 3 Now that you’re acquain
Page 188:
Chapter 3 It’s as simple as that!
Page 192:
Chapter 3 76 YearReleased 1947 1967
Page 196:
Chapter 3 78 FilmName Rating Gone w
Page 200:
Chapter 3 2. Add a WHERE clause to
Page 204:
Chapter 3 Executing this SQL provid
Page 208:
Chapter 3 84 FullName First name is
Page 212:
Chapter 3 86 FullName First name is
Page 216:
Chapter 3 Even though DateOfBirth i
Page 220:
Chapter 3 Member Name The member is
Page 224:
Chapter 3 92 The preceding SQL prod
Page 228:
Chapter 3 94 ❑ Category ❑ FavCa
Page 232:
Chapter 3 96 You’re one step furt
Page 236:
Chapter 3 98 FirstName LastName Cat
Page 240:
Chapter 3 This time, you achieve mo
Page 244:
Chapter 3 SQL Is Set-Based 102 You
Page 248:
Chapter 3 104 Category MemberId Thr
Page 252:
Chapter 3 106 You should see the fo
Page 256:
Chapter 3 The overlapping portions
Page 260:
Chapter 3 110 More than one conditi
Page 264:
Chapter 3 112 Next, link the Member
Page 268:
Chapter 3 114 FirstName LastName Da
Page 272:
Chapter 3 ❑ The slightly tricky t
Page 276:
Chapter 4 normalization can make da
Page 280:
Chapter 4 120 Field Name Data Type
Page 284:
Chapter 4 122 The Street, City, and
Page 288:
Chapter 4 MySQL versions prior to 5
Page 292:
Chapter 4 126 Except for IBM’s DB
Page 296:
Chapter 4 128 You can add more than
Page 300:
Chapter 4 Try It Out Adding a CHECK
Page 304:
Chapter 4 Obviously, if the table i
Page 308:
Chapter 4 134 Drop the MoreHolidayB
Page 312:
Chapter 4 136 If you want to return
Page 316:
Chapter 4 If you’re using IBM DB2
Page 320:
Chapter 4 140 index helps speed up
Page 324:
Chapter 4 142 The results you get m
Page 328:
Chapter 4 144 The results of the qu
Page 332:
Chapter 4 146 Remember, IBM DB2 doe
Page 336:
Chapter 4 148 UPDATE Films SET Film
Page 340:
Chapter 4 150 Finally, you do the s
Page 344:
Chapter 4 152 SELECT * FROM MemberD
Page 348:
Chapter 4 ❑ Choose meaningful nam
Page 354:
5 Manipulating Data In Chapter 3, y
Page 358:
The results of this query are as fo
Page 362:
You can raise a number to any power
Page 366:
To demonstrate the sort of results
Page 370:
The CEILING() Function The CEILING(
Page 374:
ased on the digits after the decima
Page 378:
The SUBSTRING() function works at t
Page 382:
LastName UPPER(LastName) LOWER(Last
Page 386:
The LENGTH() function takes just on
Page 390:
LastName LOWER(SUBSTRING(LastName,1
Page 394:
FirstName DIFFERENCE(FirstName, ‘
Page 398:
Converting Different Data Types Thi
Page 402:
CREATE Table MyTable(FirstColumn in
Page 406:
The COALESCE() Function The COALESC
Page 410:
Ideally, this first argument is the
Page 414:
LocationId Street City State 1 Main
Page 418:
6 Grouping and Aggregating Data So
Page 422:
Running the query, complete with a
Page 426:
MemberId Street City State 11 Newis
Page 430:
Executing the SQL returns seven dis
Page 434:
For example, the following code add
Page 438:
Running the query gives the answer
Page 442:
SELECT MAX(LastName), MIN(LastName)
Page 446:
immediately after the GROUP BY stat
Page 450:
Executing the final SQL provides th
Page 456:
Chapter 7 The INNER JOIN links the
Page 460:
Chapter 7 FilmName FirstName LastNa
Page 464:
Chapter 7 212 As mentioned, that wo
Page 468:
Chapter 7 Category Street Romance T
Page 472: Chapter 7 216 MD1.First MD1.Last MD
Page 476: Chapter 7 SELECT MD1.MemberId, MD1.
Page 480: Chapter 7 220 SELECT Category, Film
Page 484: Chapter 7 222 Location.Street Membe
Page 488: Chapter 7 224 Category MemberId War
Page 492: Chapter 7 Look at the results that
Page 496: Chapter 7 228 The Maltese Poodle 8
Page 500: Chapter 7 230 9 10 11 12 13 14 15 1
Page 504: Chapter 7 232 On Golden Puddle 1967
Page 510: 8 Queries within Queries This chapt
Page 514: There are no films with a value in
Page 518: The error wording depends on the da
Page 522: Now execute the query. You receive
Page 528: Chapter 8 244 There is one area in
Page 532: Chapter 8 246 SELECT FirstName, Las
Page 536: Chapter 8 248 The subquery (SELECT
Page 540: Chapter 8 250 Notice the use of the
Page 544: Chapter 8 4. You should receive the
Page 548: Chapter 8 254 This inner query retu
Page 552: Chapter 8 It’s quite important no
Page 556: Chapter 8 258 To tackle this query,
Page 560: Chapter 8 260 Now you need to find
Page 566: 9 Advanced Queries In database prog
Page 570: FOREIGN KEY (OrderId) REFERENCES Or
Page 574:
INSERT INTO Orders(OrderId, MemberI
Page 578:
INSERT INTO OrderItems(OrderId,Film
Page 582:
A more complex question could be,
Page 586:
Advanced Queries What you really wa
Page 590:
FirstName and LastName. You need to
Page 594:
2. The film club chairperson also w
Page 598:
Executing the preceding query provi
Page 602:
GROUP BY SalesPerson.SalesPersonId,
Page 606:
Executing the preceding SQL creates
Page 610:
❑ Use IN with your subqueries. Wh
Page 614:
10 Views Views, as the name implies
Page 618:
Try It Out Building a View 1. The p
Page 622:
FROM dbo.MemberDetails INNER JOIN d
Page 626:
For example, you might want a list
Page 630:
However, if you take the case of Me
Page 634:
However, someone writes a query tha
Page 638:
Summary As you learned, views are l
Page 644:
Chapter 11 The information that fol
Page 648:
Chapter 11 This SQL adds formats (d
Page 652:
Chapter 11 TRANSACTION statement is
Page 656:
Chapter 11 Additionally, if a DBMS
Page 660:
Chapter 11 ROLLBACK TRANSACTION 310
Page 664:
Chapter 11 Transaction Logs 312 How
Page 668:
Chapter 11 Database There are perfe
Page 672:
Chapter 11 In order to find and fix
Page 676:
Chapter 11 When discussing locking,
Page 680:
Chapter 11 Usually, the default iso
Page 684:
Chapter 11 From Sue’s perspective
Page 688:
Chapter 11 5. At this point, you ne
Page 694:
12 SQL Security In today’s world,
Page 698:
Setting up security begins with cre
Page 702:
ALTER USER username options ALTER U
Page 706:
In Figure 12-3, three different gro
Page 710:
How It Works After you run this sta
Page 714:
check constraints can be used in a
Page 718:
You could then give SELECT privileg
Page 722:
Limitations on Views Views are by t
Page 726:
GRANT SELECT (NAME, SSN, SALARY) ON
Page 730:
Betsey also grants privileges to Ji
Page 734:
The CASCADE option tells the DBMS t
Page 738:
13 Database Tuning SQL is a languag
Page 742:
Perhaps this doesn’t sound remote
Page 746:
When an application asks for data f
Page 750:
The point of all the discussion of
Page 754:
How Do You Do It? And herein lies t
Page 758:
The slots are often implemented as
Page 762:
On the other hand, an index on a tr
Page 766:
Tuning Tips The following list cont
Page 770:
Database Tuning Exercises 1. Create
Page 776:
Appendix A Exercise 2 Solution 368
Page 780:
Appendix A ( 8, ‘Jack’, ‘John
Page 784:
Appendix A ZipCode, Email, DateOfJo
Page 788:
Appendix A Exercise 3 Solution Firs
Page 792:
Appendix A 376 Figure A-1 ISBN is a
Page 796:
Appendix A Chapter 5 Exercise 1 Sol
Page 800:
Appendix A 380 You might receive sl
Page 804:
Appendix A 382 You should use the f
Page 808:
Appendix A Your answer may differ,
Page 812:
Appendix A WHERE (SELECT COUNT(*) f
Page 816:
Appendix A Exercise 2 Solution CREA
Page 820:
Appendix A Chapter 13 Exercise 1 So
Page 824:
Appendix B 392 Click the database i
Page 828:
Appendix B 394 Click Install to beg
Page 832:
Appendix B 396 Select the Detailed
Page 836:
Appendix B 398 Leave it at the defa
Page 840:
Appendix B 400 Having entered your
Page 844:
Appendix B 402 Figure B-20 The inst
Page 848:
Appendix B 404 At the very top of t
Page 852:
Appendix B 406 Having done that, ma
Page 856:
Appendix B 408 Figure B-30 MyTable
Page 860:
Appendix B 410 Figure B-32 Click Ne
Page 864:
Appendix B 412 Click Next to contin
Page 868:
Appendix B 414 Click OK to clear th
Page 872:
Appendix B If you’re ready and ha
Page 876:
Appendix B 418 You can also enter a
Page 880:
Appendix B 420 Figure B-49 The Film
Page 884:
Appendix B 422 Now you need to inse
Page 888:
Appendix B 424 In Access it’s not
Page 892:
Appendix B 426 Figure B-56 You need
Page 896:
Appendix B 428 Then click the Run i
Page 900:
Appendix B 430 The next screen (see
Page 904:
Appendix B 432 On the next screen,
Page 908:
Appendix B 434 Click Next to procee
Page 912:
Appendix B 436 Figure B-72 The huge
Page 916:
Appendix B 438 Figure B-74 Notice t
Page 920:
Appendix B 440 Figure B-76 The Obje
Page 924:
Appendix B 442 Figure B-78 Chapter
Page 928:
Appendix B You don’t need MyTable
Page 932:
Appendix B 446 Figure B-82 To begin
Page 936:
Appendix B Using Oracle’s SQL*Plu
Page 940:
Appendix B 450 Figure B-87 Another
Page 944:
Appendix C Category Table The follo
Page 948:
Appendix C 454 ( 3, ‘Sandra’,
Page 952:
Appendix C 456 ZipCode, Email, Date
Page 956:
Appendix C DateOfJoining ) VALUES (
Page 960:
Appendix C 460 VALUES ( 1, 3 ); INS
Page 964:
Appendix C VALUES ( 5, 3 ); INSERT
Page 968:
Appendix C 464 3 ); INSERT INTO Fil
Page 972:
Appendix C 5, 6 ); INSERT INTO Film
Page 976:
Appendix C 468 5 ); INSERT INTO Att
Page 980:
Appendix C Oracle 470 To save some
Page 984:
Appendix C 472 LocationId, MeetingD
Page 990:
Symbols + (addition operator), 82,
Page 994:
BEGIN TRANSACTION statement, 306, 3
Page 998:
SERIALIZABLE statement, 318 SET TRA
Page 1002:
data types brackets, 25 categories,
Page 1006:
Oracle concatenation, 85-88 configu
Page 1010:
error messages debugging, 26 subque
Page 1014:
concatenation, 85-88 data type comp
Page 1018:
primary keys database creation exam
Page 1022:
concurrent connection selection, 39
Page 1026:
passwords group access, 333 IBM ins
Page 1030:
ROLLBACK statement, 307-308 ROLLBAC
Page 1034:
REPEATABLE READ, 319 REVOKE, 344-34
Page 1038:
telephone numbers, data type select
Page 1042:
historical, data selection, 90-94 N
show all

Beginning SQL

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?