Test268 Section 1

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Section 1 - Externally Described Files in Programs (14%)

Use printer files and "O" specs to define output in a program

Even though this is not used as much anymore, there is still a lot of programs out there that still use this.

FFilename++IPEASFRlen+LKlen+AIDevice+.Keywords+++++++++++++++++++++++++++++Comments++++++++++++
FMYOUTPUT  O    F  132        PRINTER OFLIND(OVERFLOW)                                         

OFilename++DF..N01N02N03Excnam++++B++A++Sb+Sa+.............................Comments++++++++++++
OMYOUTPUT  E            HEADINGS          2  1                                                 
O          E            HEADINGS2         2                                                    
O          E            DETAILLINE        1                                                    
O          E            BREAKLINE         1                                                    
O          E            TOTALLINE         1

Use database file I/O operations in a program

Grab one particular record in a file:

      chain (employee) empfile;

Write a record:

      write roperator;

Set the pointer to a spot in the file then read all records that match the key:

      setll (employee) emphist;
      reade (employee) emphist;
      
      dow not %eof();
        ::: Logic here :::
        reade (employee) emphist;
      enddo;

Update a record:

      update record;

Use display file I/O operations in a program

Write a display record:

      write footer;

EXFMT:

      exfmt screen1;

Read a display record:

      read screen;

Use externally described database files in a program

FFilename++IPEASF.....L.....A.Device+.Keywords+++++++++++++++++++++++++++++Comments++++++++++++
FMYFILE    IF   E           K DISK

Use externally-described printer files in a program

FFilename++IPEASFRlen+LKlen+AIDevice+.Keywords+++++++++++++++++++++++++++++Comments++++++++++++
FREPORT    O    E             PRINTER USROPN OFLIND(*IN40)

Use externally-described display files in a program

FFilename++IPEASF.....L.....A.Device+.Keywords+++++++++++++++++++++++++++++Comments++++++++++++
FREPORT    CF   E             WORKSTN

Create DDS externally described files

.....A..........T.Name++++++RLen++TDpB......Functions+++++++++++++++++++++++++++
     A          R CURCOEMAIL         
     A            CMPNY          4  0
     A            EMAILADDR1   100   
     A            EMAILADDR2   100

Create SQL externally described files

CREATE TABLE LAWCUSTDBF.CUPCOEMAIL ( 
       CMPNY DECIMAL(4, 0) NOT NULL DEFAULT 0 , 
       EMAILADDR1 CHAR(100) CCSID 37 NOT NULL DEFAULT  , 
       EMAILADDR2 CHAR(100) CCSID 37 NOT NULL DEFAULT  ) ;

Use EXTFILE. EXTMBR and OPEN/CLOSE file operations in a program

EXTFILE

specify the value in any of the following forms:

|filename |libname/filename |*LIBL/filename |Notes:

|You cannot specify *CURLIB as the library name.

|If you specify a file name without a library name, *LIBL is used.

|The name must be in the correct case. For example, if you specify |EXTFILE(filename) and variable filename has the value |'qtemp/myfile', the file will not be found. |Instead, it should have the value 'QTEMP/MYFILE'.

|This keyword is not used to find an externally-described file at compile |time.

|If a variable name is used, it must be set before the file is |opened. For files that are opened automatically during the |initialization part of the cycle, the variable must be set in one of the |following ways: ||Using the INZ keyword on the D specification |Passing the value in as an entry parameter |Using a program-global variable that is set by another module. |||If you have specified an override for the file that RPG will open, that |override will be in effect. In the following code, for the file named |INPUT within the RPG program, the file that is opened at runtime |depends on the value of the filename field.

| Finput if f 10 disk extfile(filename)

EXTMBR

EXTMBR(membername) | |The EXTMBR keyword specifies which member of the file is opened. You |can specify a member name, '*ALL', or |'*FIRST'. Note that '*ALL' and |'*FIRST' must be specified in quotes, since they are member "names", |not RPG special words. The value can be a literal or a variable. |The default is '*FIRST'.

|The name must be in the correct case. For example, if you specify |EXTMBR(mbrname) and variable mbrname has the value |'mbr1', the member will not be found. Instead, it |should have the value 'MBR1'.

|If a variable name is used, it must be set before the file is |opened. For files that are opened automatically during the |initialization part of the cycle, the variable must be set in one of the |following ways: | |Using the INZ keyword on the D specification |Passing the value in as an entry parameter |Using a program-global variable that is set by another module

OPEN

open myfile;

CLOSE

close myfile;

FFilename++IPEASFRlen+LKlen+AIDevice+.Keywords+++++++++++++++++++++++++++++Comments++++++++++++ FMYFILE IF E DISK PREFIX(SS)

you can also include the number of albhabets to be replaced.ie;PREFIX(SS:2)

When using externally described files, show how to rename record formats in a program

FFilename++IPEASFRlen+LKlen+AIDevice+.Keywords+++++++++++++++++++++++++++++Comments++++++++++++
FMYFILE    IF   E             DISK    RENAME(MYFILE:MYREC)

Create Physical, Logical/View, Printer, and Display externally described files

Use a field reference file to create an externally described file