Web Programming with PL/SQL Erdogan Dogdu Georgia State University Computer Science Department...

Web Programming with PL/SQL

Erdogan DogduGeorgia State University

Computer Science Department

[email protected]

http://db.gsu.edu/~edogdu

mailto:[email protected]

http://db.gsu.edu/~edogdu

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Content

Oracle Architecture for Web Apps Oracle mod_plsql Apache module HTTP A Simple PL/SQL Web Toolkit Example PL/SQL Web Toolkit Parameter Passing HTML Forms PL/SQL Server Pages

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Oracle Web Extensions

• 3-tier: client, application server (OAS 9i), database (Oracle 9i)

• mod_plsql in OAS• PL/SQL Web Toolkit

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Web Request Processing

1. The Oracle HTTP Server receives a PL/SQL Server Page request from a client browser.

2. The Oracle HTTP Server routes the request to mod_plsql.

3. The request is forwarded by mod_plsql to the Oracle Database. By using the configuration information stored in your DAD, mod_plsql connects to the database.

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Web Request Processing (cont.)

4. Mod_plsql prepares the call parameters, and invokes the PL/SQL procedure in the application.

5. The PL/SQL procedure generates an HTML page using data and the PL/SQL Web Toolkit accessed from the database.

6. The response is returned to mod_plsql. 7. The Oracle HTTP Server sends the

response to the client browser.

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Invoking mod_plsql

protocol://hostname[:port]/DAD location/[[!][schema.][package.]proc_ name[?query_string]]

Example:– http://db.gsu.edu:7777/pls/csc8711/

simple

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HTTP

GET, POST, HEAD methodsGET. Parameters in query string.

• http://host:port/pls/DAD/foo?a=v&b=1POST. For large parameter data.

– http://host:port/pls/DAD/foo, POST data="a=v&b=1“

HEAD. No content data is streamed back. Only a confirmation.

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A Simple Example

Write a PL/SQL procedure (simple.sql) using PL/SQL Web Toolkit:

CREATE OR REPLACE PROCEDURE simple ASl_user varchar2(30);BEGIN select USER into l_user from dual; htp.htmlOpen; htp.headOpen; htp.title('A Very Very Simple Example'); htp.headClose; htp.bodyOpen; htp.line; htp.header(1,'Simple Example'); htp.line; htp.paragraph;…

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A Simple Example (cont.)… htp.print('Today''s date is: ' || to_char(sysdate, 'DD/MM/YYYY')); htp.br; htp.print('Today''s day is: ' || to_char(sysdate, 'DAY')); htp.paragraph; htp.print('Ordinary <em>tags</em> can be used in the strings that we send.'); htp.print('Your Oracle USERID is ' || l_user); htp.line; htp.address('Raj Sunderraman'); -- owa_util.signature('orarbkx.simple'); htp.bodyClose; htp.htmlClose; EXCEPTION When others Then htp.print(SQLERRM); htp.bodyClose; htp.htmlClose;END;/show errors

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A Simple Example (cont.)

Upload the procedure ‘simple’ to the database:> sqlplusSQL> @simple.sqlProcedure created.No errors.

Run procedure:http://db.gsu.edu:7777/pls/csc8711/simple

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Web Toolkit

Oracle Web Toolkit includes a number of packages:

htp and htf package: hypertext procedures and functions,

owa_cookie: to handle HTTP cookies,owa_util: utility subprograms,etc.

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htp package

Example:create or replace procedure hello ASBEGIN

htp.htmlopen; -- generates <HTML>htp.headopen; -- generates <HEAD>htp.title('Hello'); -- generates <TITLE>Hello</TITLE>htp.headclose; -- generates </HEAD>htp.bodyopen; -- generates <BODY>htp.header(1, 'Hello'); -- generates <H1>Hello</H1>htp.bodyclose; -- generates </BODY>htp.htmlclose; -- generates </HTML>

END;

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htp and htf package

More htp functions:– Comment: htp.comment– Applet: htp.appletopen, …– List: htp.olistOpen, htp.ulinstOpen, …– Form: htp.formOpen, …– Table: htp.tableOpen, htp.tableData, …– Image: htp.img, etc.– Formatting: htp.print, htp.bold, htp.underline, …– Frame: htp.frame, …

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owa_util

owa_util.tablePrint

create or replace procedure showemps isignore_more boolean;

beginignore_more := owa_util.tablePrint('emp', 'BORDER', OWA_UTIL.PRE_ TABLE);

end;

This procedure gives the output (next slide)

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owa_util

<PRE> ----------------------------------------------------------------- | EMPNO |ENAME |JOB |MGR |HIREDATE | SAL | COMM | DEPTNO | ----------------------------------------------------------------- | 7369| SMITH | CLERK | 7902 | 17-DEC-80 | 800 | | 20 | | 7499| ALLEN | SALESMAN| 7698 | 20-FEB-81 | 1600 | 300 | 30 | | 7521| WARD | SALESMAN| 7698 | 22-FEB-81 | 1250 | 500 | 30 | | 7566| JONES | MANAGER | 7839 | 02-APR-81 | 2975 | | 20 | | 7654| MARTIN | SALESMAN| 7698 | 28-SEP-81 | 1250 | 1400| 30 | | 7698| BLAKE | MANAGER | 7839 | 01-MAY-81 | 2850 | | 30 | | 7900| JAMES | CLERK | 7698 | 03-DEC-81 | 950 | | 30 | | 7902| FORD | ANALYST | 7566 | 03-DEC-81 | 3000 | | 20 | | 7934| MILLER | CLERK | 7782 | 23-JAN-82 | 1300 | | 10 | ----------------------------------------------------------------- </PRE>

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Passing Parameters

GET method

http://db:7777/pls/csc8711/pl1?str=Hello&num=4

create or replace procedure pl1(str in varchar2, num in number) as

beginfor i in 1..num loop

htp.print(i || '. ' || str);htp.br;

end loop;end;

1. Hello<br>2. Hello<br>3. Hello<br>4. Hello<br>

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HTML Forms

htp.formOpen(curl in varchar2, cmethod in varchar2 default ‘POST’, ctarget in varchar2, cenctype in varchar2 default null, cattributes in varchar2 default null);

<FORM ACTION=“curl” METHOD=“cmethod” TARGET=“ctarget” ENCTYPE=“cenctype” cattributes>

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HTML Forms

htp.formSubmit(cname in varchar2 default null, cvalue in varchar2 default ‘Submit’, cattributes in varchar2 default null)

<INPUT TYPE=“submit” NAME=“cname” VALUE=“cvalue” cattributes>

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HTML Forms

HTML forms can have the following elements:– Single line input text (htp.formText)– Single line input password (htp.formPassword)– Checkboxes (htp.formCheckbox)– Radio buttons (htp.formRadio)– Submit buttons (htp.formSubmit)– Text areas (htp.formTextarea)– Selects (htp.formSelectOpen,

htp.formSelectOption, htp.formSelectClose)

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HTML Forms

Useful functions:owa_util.get_owa_service_path: Returns

the prefix of the URL pointing to PL/SQL procedure

Example:http://db.gsu.edu:7777/pls/survey/login

Use in PL/SQL web program as:htp.formOpen(owa_util.get_owa_service_

path || ‘start_session’);

http://db.gsu.edu:7777/pls/survey/login

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Disadvantages of Web Toolkit

PL/SQL Web Toolkit (htp, htf) generates HTML code form PL/SQL programs.

Generating nice web pages is difficult, you cannot author PL/SQL programs in Frontpage.

Solution is PSP (next)

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PL/SQL Server Pages (PSP)

Author web pages using script-friendly HTML authoring tools.

Drop in PL/SQL code in web pages.In short:

– Web Toolkit: generate HTML from PL/SQL– PSP: embedded PL/SQL within HTML

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Same script tag syntax as JSP, also similar to ASP

PSP files should have .psp extensionCan be as simple as an HTML page (no

PL/SQL script)Specifying the scripting language

<%@ page language="PL/SQL" %>

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Parameter passing<

%@ plsql parameter="varname" %>

Returned document type<

%@ page contentType="MIMEtype" %>

Such as text/xml, text/plain, image/jpeg

Stored procedure name<

%@ page procedure="procname" %>

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Loading psp document to Oracle

loadpsp [ -replace ] -user username/password[@connect_string] [

include_file_name ... ] [ error_file_name ] psp_file_name ...

Date post:	01-Apr-2015
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Web Programming with PL/SQL Erdogan Dogdu Georgia State University Computer Science Department...

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