Chapter 7 · 2018. 9. 1. · Microsoft PowerPoint - chapter07.ppt Author: Gwo-Jen Hwang Created Date: 2004082511406

7

1

Chapter 7

Advanced SQL

Database Systems:Design, Implementation, and Management,

Sixth Edition, Rob and Coronel

Database Systems: Design, Implementation, & Management, 6th Edition, Rob & Coronel

7

2

In this chapter, you will learn:

•About the relational set operators UNION,UNION ALL, INTERSECT, and MINUS

•How to use the advanced SQL JOIN operatorsyntax

•About the different types of subqueries andcorrelated queries

•How to use SQL functions to manipulate dates,strings, and other data


7

3

In this chapter, you will learn: (continued)

•How to create and use updatable views

•How to create and use triggers and storedprocedures

•How to create embedded SQL


7

4

UNION Query Result


7

5

UNION ALL Query Result


7

6

INTERSECT Query Result


7

7

MINUS Query Results


7

8

INTERSECT Alternative


7

9

MINUS Alternative


7

10

SQL Join Expression Styles


7

11

NATURAL JOIN Result


7

12

JOIN USING Result


7

13

JOIN ON Result


7

14

Outer Joins

•Returns not only rows matching join conditionbut also rows with unmatched values

•Three types:

–Left

–Right

–Full


7

15

LEFT JOIN Result


7

16

RIGHT JOIN Result


7

17

FULL JOIN Result


7

18

SELECT Subquery Examples


7

19

WHERE Subquery Examples


7

20

IN Subquery Example


7

21

HAVING Subquery Example


7

22

Multirow Subquery Operator Example


7

23

FROM Subquery Example


7

24

Inline Subquery Example


7

25

Correlated Subquery Examples


7

26

EXISTS Correlated Subquery Examples


7

27

Selected MS Access/SQL ServerDate/Time Functions


7

28

Selected Oracle Date/Time Functions


7

29

Selected Oracle Date/Time Functions(continued)


7

30

Selected Oracle Numeric Functions


7

31

Selected Oracle String Functions


7

32

Selected Oracle Conversion Functions


7

33

Selected Oracle Conversion Functions(continued)


7

34

Oracle Sequence


7

35

Oracle Sequence Examples


7

36

The PRODMASTERand PRODSALES Tables


7

37

The Oracle UPDATE Error Message


7

38

Creating an Updatable View in Oracle


7

39

PRODMASTER Table Update,Using an Updatable View


7

40

Anonymous PL/SQL Block Examples


7

41

SHOW ERRORS

•Can help diagnose errors found in PL/SQLblocks

•Yields additional debugging informationwhenever an error is generated after anPL/SQL block is created or executed


7

42

Anonymous PL/SQL Blockwith Variables and Loops


7

43

PL/SQL Basic Data Types


7

44

The PRODUCT Table


7

45

Creating theTRG_PRODUCT_REORDER Trigger


7

46

Verifying the TRG_PRODUCT_REORDERTrigger Execution


7

47

The P_REORDER Value Mismatch AfterUpdate of the P_MIN Attribute


7

48

Stored Procedures: Advantages

•Substantially reduce network traffic andincrease performance

•No transmission of individual SQL statementsover network

•Help reduce code duplication by means ofcode isolation and code sharing

•Minimize chance of errors and cost ofapplication development and maintenance


7

49

Creating the PRC_PROD_DISCOUNTStored Procedure


7

50

Results of the PRC_PROD_DISCOUNTStored Procedure


7

51

The PRC_CUS_ADD Stored Procedure


7

52

The PRC_INV_ADD andPRC_LINE_ADD Stored Procedures


7

53

Testing the PRC_INV_ADD andPRC_LINE_ADD Procedures


7

54

Cursor Processing Commands


7

55

Cursor Attributes


7

56

SQL and Procedural Languages:Key Differences

•Run-time mismatch:–SQL executed one instruction at a time–Host language typically runs at the client side

in its own memory space

•Processing mismatch:–Host language processes one data element at

a time

•Data type mismatch:–Data types may not match


7

57

Embedded SQL Framework

•A standard syntax to identify embedded SQLcode within host language

•A standard syntax to identify host variables

•A communication area used to exchangestatus and error information between SQLand the host language


7

58

SQL Status and Error Reporting Variables


7

59

Static SQL

•Embedded SQL in which the programmerused predefined SQL statements andparameters

–End users of programs are limited to actionsthat were specified in application programs

•SQL statements will not change whileapplication is running


7

60

Dynamic SQL

•SQL statement is not known in advance, butinstead is generated at run time

•Program can generate SQL statements at runtime that are required to respond to ad hocqueries

•Attribute list and the condition are not knownuntil the end user specifies them

•Tends to be much slower than static SQL•Requires more computer resources


7

61

Summary

•SQL provides relational set operators tocombine output of two queries to generate newrelation

•Operations that join tables can be classified asinner joins and outer joins

•Subqueries and correlated queries are usedwhen it is necessary to process data based onother processed data

•SQL functions are used to extract or transformdata


7

62

Summary (continued)

•Oracle sequences may be used to generatevalues to be assigned to a record

•PL/SQL may be used to create triggers,stored procedures, and PL/SQL functions

•If SQL statements are designed to returnmore than one value inside the PL/SQL code,a cursor is needed

•Embedded SQL refers to the use of SQLstatements within an applicationprogramming language

Documents

Chapter 7 · 2018. 9. 1. · Microsoft PowerPoint - chapter07.ppt Author: Gwo-Jen Hwang Created Date: 2004082511406