vb.net 2d barcode dll RETRIEVAL: SOME ADVANCED FEATURES in Java

Creator Data Matrix 2d barcode in Java RETRIEVAL: SOME ADVANCED FEATURES

RETRIEVAL: SOME ADVANCED FEATURES
Data Matrix 2d Barcode Generator In Java
Using Barcode encoder for Android Control to generate, create DataMatrix image in Android applications.
www.OnBarcode.com
Creating QR Code In Java
Using Barcode creation for Android Control to generate, create QR Code 2d barcode image in Android applications.
www.OnBarcode.com
ENAME ----------------KING JONES SCOTT ADAMS FORD SMITH BLAKE ALLEN WARD MARTIN TURNER JONES CLARK MILLER
Barcode Creation In Java
Using Barcode creator for Android Control to generate, create Barcode image in Android applications.
www.OnBarcode.com
Draw Barcode In Java
Using Barcode drawer for Android Control to generate, create Barcode image in Android applications.
www.OnBarcode.com
CONNECT_BY_ROOT and SYS_CONNECT_BY_PATH
EAN-13 Encoder In Java
Using Barcode creator for Android Control to generate, create GS1 - 13 image in Android applications.
www.OnBarcode.com
Create Data Matrix ECC200 In Java
Using Barcode creation for Android Control to generate, create Data Matrix 2d barcode image in Android applications.
www.OnBarcode.com
If you use START WITH and CONNECT BY to define a hierarchical query, you can use two interesting hierarchical operators in the SELECT clause: CONNECT_BY_ROOT: This operator allows you to connect each row (regardless of its level in the tree structure) with its own root. SYS_CONNECT_BY_PATH: This function allows you to display the full path from the current row to its root.
Generate UPC Code In Java
Using Barcode generator for Android Control to generate, create UPC-A image in Android applications.
www.OnBarcode.com
UPCE Encoder In Java
Using Barcode encoder for Android Control to generate, create Universal Product Code version E image in Android applications.
www.OnBarcode.com
See Listing 9-21 for an example of using both operators. Note that the START WITH clause in Listing 921 creates three separate tree structures: one for each manager. Listing 9-21. Using CONNECT_BY_ROOT and SYS_CONNECT_BY_PATH select , , from start connect ENAME -------JONES SCOTT ADAMS FORD SMITH BLAKE ALLEN WARD MARTIN ename connect_by_root ename as manager sys_connect_by_path(ename,' > ') as full_path employees with job = 'MANAGER' by prior empno = mgr; MANAGER FULL_PATH -------- ------------------------JONES > JONES JONES > JONES > SCOTT JONES > JONES > SCOTT > ADAMS JONES > JONES > FORD JONES > JONES > FORD > SMITH BLAKE > BLAKE BLAKE > BLAKE > ALLEN BLAKE > BLAKE > WARD BLAKE > BLAKE > MARTIN
ECC200 Encoder In Visual Studio .NET
Using Barcode encoder for Reporting Service Control to generate, create DataMatrix image in Reporting Service applications.
www.OnBarcode.com
ECC200 Generator In Objective-C
Using Barcode printer for iPad Control to generate, create Data Matrix 2d barcode image in iPad applications.
www.OnBarcode.com
RETRIEVAL: SOME ADVANCED FEATURES
UPC-A Supplement 5 Encoder In None
Using Barcode generator for Microsoft Word Control to generate, create UPC-A Supplement 5 image in Office Word applications.
www.OnBarcode.com
Barcode Reader In VS .NET
Using Barcode reader for .NET framework Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
TURNER JONES CLARK MILLER
Encode Data Matrix ECC200 In None
Using Barcode creator for Online Control to generate, create DataMatrix image in Online applications.
www.OnBarcode.com
Linear Generation In .NET Framework
Using Barcode creation for ASP.NET Control to generate, create Linear image in ASP.NET applications.
www.OnBarcode.com
BLAKE BLAKE CLARK CLARK
Creating Code 128B In Java
Using Barcode encoder for Eclipse BIRT Control to generate, create Code 128A image in Eclipse BIRT applications.
www.OnBarcode.com
PDF417 Generator In None
Using Barcode creator for Excel Control to generate, create PDF 417 image in Excel applications.
www.OnBarcode.com
> > > >
QR Code Drawer In .NET Framework
Using Barcode creator for Reporting Service Control to generate, create QR Code JIS X 0510 image in Reporting Service applications.
www.OnBarcode.com
Barcode Reader In Java
Using Barcode Control SDK for BIRT Control to generate, create, read, scan barcode image in Eclipse BIRT applications.
www.OnBarcode.com
BLAKE > TURNER BLAKE > JONES CLARK CLARK > MILLER
Create Barcode In None
Using Barcode maker for Office Word Control to generate, create Barcode image in Word applications.
www.OnBarcode.com
Draw Barcode In Java
Using Barcode creation for Eclipse BIRT Control to generate, create Barcode image in BIRT reports applications.
www.OnBarcode.com
You can specify additional conditions in the CONNECT BY clause, thus eliminating entire subtree structures. Note the important difference with conditions in the WHERE clause: those conditions filter only individual rows. See Oracle SQL Reference for more details and examples.
Hierarchical Query Result Sorting
If you want to sort the results of hierarchical queries, and you use a regular ORDER BY clause, the carefully constructed hierarchical tree gets disturbed in most cases. In such cases, you can use the SIBLINGS option of the ORDER BY clause. This option doesn t destroy the hierarchy of the rows in the result. See Listings 9-22 and 9-23 for an example, and watch what happens with the query result if we remove the SIBLINGS option. Listing 9-22 shows the use of siblings. Listing 9-23 shows the results without that keyword. Listing 9-22. Results when ordering by siblings select , from start connect order ENAME -------KING BLAKE ALLEN JONES MARTIN TURNER WARD CLARK MILLER JONES FORD SMITH SCOTT ADAMS ename sys_connect_by_path(ename,'|') as path employees with mgr is null by prior empno = mgr SIBLINGS by ename; PATH ----------------------------|KING |KING|BLAKE |KING|BLAKE|ALLEN |KING|BLAKE|JONES |KING|BLAKE|MARTIN |KING|BLAKE|TURNER |KING|BLAKE|WARD |KING|CLARK |KING|CLARK|MILLER |KING|JONES |KING|JONES|FORD |KING|JONES|FORD|SMITH |KING|JONES|SCOTT |KING|JONES|SCOTT|ADAMS
Listing 9-23. Results from a standard ORDER BY clause select , from ename sys_connect_by_path(ename,'|') as path employees
RETRIEVAL: SOME ADVANCED FEATURES
start with mgr is null connect by prior empno = mgr order by ename; ENAME -------ADAMS ALLEN BLAKE CLARK FORD JONES JONES KING MARTIN MILLER SCOTT SMITH TURNER WARD PATH -----------------------------|KING|JONES|SCOTT|ADAMS |KING|BLAKE|ALLEN |KING|BLAKE |KING|CLARK |KING|JONES|FORD |KING|JONES |KING|BLAKE|JONES |KING |KING|BLAKE|MARTIN |KING|CLARK|MILLER |KING|JONES|SCOTT |KING|JONES|FORD|SMITH |KING|BLAKE|TURNER |KING|BLAKE|WARD
9.6 Analytical Functions
This section introduces the concept of analytical functions, which are a very powerful part of the ANSI/ISO SQL standard syntax. Analytical functions enable you to produce derived attributes that would otherwise be very complicated to achieve in SQL. Rankings, Top N reports, and running totals are all possible using analytical SQL. Not just possible, but the resulting statement is clear and performance is usually better than multiple-pass statements. Earlier in this chapter, in Section 9.2, you saw how subqueries in the SELECT clause allow you to add derived attributes to the SELECT clause of your queries. Analytical functions provide similar functionality, though with enhanced statement clarity and improved performance.
Note You always should test the performance of the analytical functions on production-like data sets. These functions are designed for use with large data sets and are optimized accordingly. When these functions are used with small data sets, as you might find in development, they may not perform as well as other statements. Do not conclude that the performance is unacceptable until you test with appropriately sized data sets.
Let s take a look at a simple query, reporting the salary ranking by department for all employees. Listing 9-24 shows the query and the results.
Copyright © OnBarcode.com . All rights reserved.