SheerPower® 4GL
A Guide to the SheerPower Language
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EXAMPLE:

Example 15-19 Extract a range of keys - TO expr option 

  open structure cl: name 'sheerpower:samples\client' 
  input 'Enter the lowest ID to check': lowest 
  input 'Enter the highest ID to check': highest 
  extract structure cl: key id = lowest to highest
    print cl(id); tab(10); cl(last) 
  end extract
  close structure cl 
  end
 
 
Enter the lowest ID to check? 80540 
Enter the highest ID to check? 80570 
80542    Brock 
80543    Cass 
80561    Derringer

15.7.6 EXTRACT STRUCTURE, FIELD: PARTIAL KEY

FORMAT:


        EXTRACT STRUCTURE struc_name, FIELD field_expr: PARTIAL KEY str_expr

EXAMPLE:

Example 15-20 PARTIAL KEY option in EXTRACT STRUCTURE 

  open structure cl: name 'sheerpower:samples\client' 
  extract structure cl, field last: partial key 'Rod' 
  end extract
  print 'List of clients with last name starting with Rod' 
  print
  for each cl 
    print cl(first); ' '; cl(last) 
  next cl 
  close structure cl 
  end
 
 
Homero Rodrigues

DESCRIPTION:

The PARTIAL KEY option will search in the EXTRACT STRUCTURE for part of a key value.

The above example program creates an extract list containing only those clients with a last name starting with "ROS".

Below is a structure with the following client information with the ID as a key field: 


         ID #      LAST      FIRST      CITY      STATE  PHONE 
      +------+-----------+--------+--------------+--+----------+ 
      |80543 |Roberts    |Cathy   | San Diego    |CA|6197438582| 
      |80542 |Roske      |Bud     | Duluth       |MN|2185554322| 
      |80522 |Rost       |Earl    | Monterey     |CA|4088447676| 
      |80561 |Rosty      |Dale    | Los Angeles  |CA|8182239014| 
      |80531 |Abott      |Al      | New York     |NY|2025669892| 
      |80573 |Farmer     |Fred    | Miami        |FL|3055527872|

15.7.7 CANCEL EXTRACT

FORMAT:


        CANCEL EXTRACT

EXAMPLE:

Example 15-21 CANCEL EXTRACT 

  open structure cl: name 'sheerpower:samples\client' 
  extract structure cl 
    print 'Client: '; cl(last) 
    line input 'Press enter to continue': z$ 
    if  _exit  then cancel extract
  end extract
  print 'Records extracted:'; _extracted
  close structure cl 
  end
 
 
Client: Smith 
Press enter to continue? EXIT 
Records extracted: 0

DESCRIPTION:

CANCEL EXTRACT cancels the current extract of a record and transfers control to the next statement after the END EXTRACT statement.

This statement can only be used within an EXTRACT block---that is, between an EXTRACT STRUCTURE and an END EXTRACT pair of statements.

15.7.8 EXIT EXTRACT

FORMAT:


        EXIT EXTRACT

EXAMPLE:

Example 15-22 EXIT EXTRACT 

  open structure cl: name 'sheerpower:samples\client' 
  extract structure cl 
    print 'Client: '; cl(last) 
    line input 'Press enter to continue': z$ 
    if  _exit  then exit extract
  end extract
  print 'Records extracted:'; _extracted 
  end
 
 
Client: Smith 
Press enter to continue? <ENTER> 
Client: Kent 
Press enter to continue? EXIT 
Records extracted: 1

DESCRIPTION:

EXIT EXTRACT passes control to the corresponding END EXTRACT statement, performs final sorting (if any), and creates the extracted collection.

15.7.9 REEXTRACT STRUCTURE

FORMAT:


        REEXTRACT STRUCTURE struc_name 
                  --- 
           [INCLUDE | EXCLUDE] cond_expr... 
           [SORT [ASCENDING | DESCENDING] BY expression... 
                  --- 
        END EXTRACT

EXAMPLE:

Example 15-23 REEXTRACT STRUCTURE ... END EXTRACT 

  open structure cl: name 'sheerpower:samples\client', access input
  extract structure cl 
    include cl(state) = 'CA' 
  end extract
  reextract structure cl 
    exclude cl(phone)[1:3] <> '619' 
    sort ascending by cl(last) 
  end extract
  print 'List of California Clients in Area Code 619' 
  for each cl 
    print cl(first); ' '; cl(last), cl(phone) 
  next cl 
  close structure cl 
  end
 
 
List of California Clients in Area Code 619 
Cathy Cass          (619) 743-8582 
Paul Johnson        (619) 489-5551 
Keith Kent          (619) 967-5021 
Pete Porter         (619) 778-6709 
Wayne Waters        (619) 564-1231

DESCRIPTION:

REEXTRACT STRUCTURE can be used to do a second extract on a list of structure records you previously extracted. This allows for increasingly specific records to be chosen through a series of REEXTRACTs.

REEXTRACT does an extract on the list of records previously extracted. struc_name is the structure name associated with an open structure.

END EXTRACT marks the end of the REEXTRACT construct. REEXTRACT operates the same as EXTRACT. However, REEXTRACT operates on a previously extracted list.

Note on EXTRACT
Extract operations by key cannot be performed with REEXTRACT.

15.7.10 EXTRACT STRUCTURE: APPEND

FORMAT:


        EXTRACT STRUCTURE struc_name: APPEND

EXAMPLE:

Example 15-24 APPEND option in EXTRACT STRUCTURE 

  open structure detail: name 'sheerpower:samples\detail' 
  set structure detail: extracted 0 
  extract structure detail, field lineid : & 
      key '10301001' to '10302000', append
    sort by detail(prodnbr) 
    sort by detail(invnbr) 
  end extract
  extract structure detail, field lineid : & 
      key '10311001' to '10312000', append
    sort by detail(prodnbr) 
    sort by detail(invnbr) 
  end extract
  print 'Prod'; tab(7); 'Line ID'; tab(17); 'Quantity' 
  for each detail 
    print detail(prodnbr); tab(7); detail(lineid); & 
        tab(17); detail(qty) 
  next detail 
  end
 
 
Prod  Line ID   Qty 
22800 10301-002      2 
22800 10301-004      1 
22800 10301-006      2 
24100 10311-003      1 
24200 10301-003      1 
24200 10311-009      1 
28400 10311-001      2 
28800 10301-009      2 
28800 10311-002      9 
28800 10311-005      1 
28800 10311-006      1 
31020 10301-005      1 
31040 10311-010      2 
31150 10301-001      1 
31150 10301-008      8 
31150 10311-004      1 
31150 10311-008      1 
33090 10301-007      2 
33090 10311-007      1

DESCRIPTION:

The EXTRACT STRUCTURE: APPEND statement adds records to the last collection of extracted records rather than creating a new collection.

15.8 ASK STRUCTURE

FORMAT:


        ASK STRUCTURE struc_name: struc_option [num_var | str_var]

DESCRIPTION:

The ASK STRUCTURE statement is used to ask about various device and structure characteristics from within your programs. struc_name is the name of a structure whose characteristics are being asked about. struc_option can be any of the structure options available. The options are explained in the following sections.

15.8.1 ASK STRUCTURE FIELD: item

FORMAT:


        ASK STRUCTURE struc_name, FIELD field_expr: item var

EXAMPLE:

Example 15-25 ASK STRUCTURE FIELD: item 

  open structure cl: name 'sheerpower:samples\client' 
  ask structure cl: fields num_fields 
  for i = 1 to num_fields 
    clear
    ask structure cl, field #i: description b$ 
    ask structure cl, field #i: prompt a$ 
    ask structure cl, field #i: position a% 
    ask structure cl, field #i: length b% 
    ask structure cl, field #i: heading f$ 
    ask structure cl, field #i: printmask c$, & 
                                screenmask d$, & 
                                help e$ 
    print at 5,5: '' 
    print 'Description   : '; b$ 
    print 'Prompt        : '; a$ 
    print 'Position      : '; a% 
    print 'Field length  :' ; b% 
    print 'Rpt. heading  : '; f$ 
    print 'Print mask    : '; c$ 
    print 'Screen mask   : '; d$ 
    print 'Help          : '; e$ 
    delay
  next i 
  close structure cl 
  end
 
 
Description   : Client ID number 
Prompt        : Client ID number 
Position      :  1 
Field length  : 5 
Rpt. heading  : CLNT,ID 
Print mask    : >#### 
Screen mask   : digits:##### 
Help          : Client ID number

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