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Developing Applications Using Informix 4GL (IX101G)

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Detaillierter Kursinhalt

IBM Informix 4GL and the IBM Informix Toolset

  • Explain to others how IBM Informix 4GL fits into the client/server architecture of IBM Informix products
  • Tell the difference between the compiled IBM Informix 4GL C Compiler Version and IBM Informix 4GL Rapid Development System.

Basic Components of IBM Informix 4GL

  • Define the terms: PROGRAM, MODULE, FUNCTION, and FORM
  • Understand how these components make up an IBM Informix 4GL program

IBM Informix 4GL The Programmers Environment

  • Navigate through the IBM Informix 4GL Programmers Environment menu
  • Choose the appropriate menu option for a given task
  • Use the alternative command-line options to create programs

Procedural Logic

  • Use IBM Informix 4GL syntax for decision logic, including IF statements and CASE statements
  • Follow IBM Informix 4GL syntax for logic loops, including WHILE loops and FOR loops

Screen Interaction Statements

  • Describe the features of the following IBM Informix 4GL statements: ERROR, MESSAGE, DISPLAY, and PROMPT
  • Modify default display characteristics for these statements using the OPTIONS statement

The MENU Statement

  • Use the MENU statement to create an IBM Informix 4GL ring menu
  • Suggest a menu path to a user
  • Create hidden menu options
  • Hide or display specific menu options

Creating a Help File: The mkmessage Utility

  • Use the mkmessage utility to compile a customized Help file for your application
  • Understand the menu used when your Help file is invoked
  • Change the default Help key
  • Include a Help option in a 4GL statement

Forms in IBM Informix 4GL

  • Create a default form
  • Select a table for a form
  • Modify a default form
  • Specify attributes for a form
  • Compile a form

Displaying Forms and Windows

  • Display a form to the screen
  • Open a window on the screen
  • Use the statements associated with clearing windows
  • Use the statements needed to release the memory used by forms and windows

Data Types in IBM Informix 4GL

  • Use the different data types in IBM Informix 4GL

Defining Program Variables

  • Define the appropriate variables for your program
  • Understand the scope of program variables
  • Know which data types can be used to define a variable in your program

The Input Statement

  • Use the INPUT statement to enter information into program variables
  • Change the default options for accepting data entry from end users

Using Clauses with the INPUT Statement

  • Controlling the movement of the cursor through a form based on user input
  • Using the value entered in one field to calculate a value for another field
  • Invoking field level help through the use of special built-in functions

The Insert Statement

  • Take the values entered by a user and insert them into a database table

The SQLCA Record

  • Recognize the variables that make up the SQLCA record
  • Understand how SQLCA record can be used

Trapping Errors with the WHENEVER Statement

  • Tell the program that you will test for errors in your IBM Informix 4GL program
  • Recover from errors in your IBM Informix 4GL program
  • Use a compile switch to change the condition of error handling

Trapping User Entered Interrupts: The DEFER INTERRUPT Statement

  • Trap the interrupt signal during data entry

A Review of the SELECT Statement

  • Use a simple SELECT statement to return one row from the database
  • Understand the syntax for more complex SELECT statements

Verifying Data in IBM Informix 4GL

  • Make code reusable
  • Call a function within an expression
  • Verify that data being entered by an end user exists in one table before allowing it to be added to another table
  • Use the SQLCA.SQLCODE variable to see whether a row was returned by a SELECT statement

An Overview of Cursors

  • Name the three types of cursors
  • Use the appropriate cursor for a given task

Transactions in IBM Informix 4GL

  • Define a transaction
  • Use the BEGIN WORK, COMMIT WORK, and ROLLBACK WORK statements in a transaction

Using Scroll Cursors

  • Use a SCROLL cursor to retrieve rows from the database
  • Use the features of a SCROLL cursor to browse through the selected rows
  • DECLARE a cursor WITH HOLD when using transactions

Query by Example: The CONSTRUCT Statement

  • Use a CONSTRUCT statement so that end users can query-byexample

Row Locking: FOR UPDATE Cursor

  • Use a cursor declared FOR UPDATE to lock a row while it is being changed or deleted

Deleting Rows in IBM Informix 4GL

  • Implement the code necessary to delete a row from a table
  • Verify that a row can be deleted
  • Prompt the user for assurance of a delete

Database Updates in IBM Informix 4GL

  • Let the user access a form to change information
  • Update a row in a database

The PREPARE Statement for Optimization

  • Use a PREPARE statement to increase the speed of execution for a DELETE statement
  • Use a PREPARE statement to increase the speed of execution for an UPDATE statement
  • Use a PREPARE statement to increase the speed of execution for an INSERT statement

Scroll Cursors and Stale Data

  • Use a SCROLL cursor to SELECT a primary key
  • Use the primary key from a SCROLL cursor as an index for a nonscrolling cursor

Forms that Use Arrays

  • Create a form that uses an array
  • Define a screen array for a form that uses an array
  • Open and display a form with an array

The INPUT ARRAY Statement

  • Define a program array of records
  • Use the INPUT ARRAY statement to allow the user to enter data
  • Use the INSERT statement to transfer the program array record values into a database table

Clauses Using INPUT ARRAY

  • Control the movement of the cursor through the elements of an array based on user input
  • Use the value entered in one field to calculate a value for another field
  • Use library functions to verify information during the input

Displaying Arrays and Pop-up Windows

  • Select data from the database into a program array
  • Use the DISPLAY ARRAY statement to allow the user to scroll through the set of data
  • Populate a program array to be used in a pop-up window
  • Implement a pop-up window to display a list of valid values for a field on a form

Reports in IBM Informix 4GL: Creating a Report Driver

  • Create a report driver using the statements: START REPORT, OUTPUT TO REPORT, and FINISH REPORT
  • Create a default report using the REPORT function

The REPORT Function

  • Use the REPORT function to format the rows received by the report driver
  • Use the seven control blocks of a report to achieve the desired appearance of a report

Advanced Report Concept: Two Reports from One SELECT

  • Use one SELECT statement in two reports
  • FORMAT the same information in two different reports

Advanced Report Concept: Using Variables to Name Output Files

  • Use a variable to name an output file
  • Use information supplied by the user to create the sort key for a report

Informix 4GL Applications as Web Services

  • Define Web Service and Service-Oriented Architecture
  • Describe the process of deploying a 4GL application to a Web service
  • Configure the 4GL development environment for Web services
  • Use the 4GL tools to manage components, compile, and deploy functions as Web services