# A basic question about workfiles and type checking... **URL:** \ **Category:** Forum\ **Tags:** Adabas-Natural, Natural, Natural-on-Mainframes\ **Created:** [January 19, 2009, 11:28pm UTC](https://techcommunity.softwareag.com/t/a-basic-question-about-workfiles-and-type-checking/79964 "2009-01-19T23:28:39Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Philip\_Chandler](https://avatars.discourse-cdn.com/v4/letter/p/b9e5f3/32.png) [@Philip\_Chandler](https://techcommunity.softwareag.com/u/Philip_Chandler)\ **Post date:** [January 19, 2009, 11:28pm UTC](https://techcommunity.softwareag.com/t/a-basic-question-about-workfiles-and-type-checking/79964/1 "2009-01-19T23:28:39Z")
I have forgotten something very basic. When reading a flat file as a workfile, there are two ways this can be handled. The first method causes Natural to perform automatic type checking. If, for example, the third field in the workfile is defined as N7, and the contents of this field on a record on the flat file are ---
**Author:** ![Ralph\_Zbrog](https://sea1.discourse-cdn.com/techcommunity/user_avatar/techcommunity.softwareag.com/ralph_zbrog/32/78_2.png) [@Ralph\_Zbrog](https://techcommunity.softwareag.com/u/Ralph_Zbrog)\ **Post date:** [January 20, 2009, 12:34am UTC](https://techcommunity.softwareag.com/t/a-basic-question-about-workfiles-and-type-checking/79964/2 "2009-01-20T00:34:54Z")
Check the documentation for more detail ([url][http://techcommunity.softwareag.com/ecosystem/documentation/natural/nat425mf/sm/readwork.htm[/url]](http://techcommunity.softwareag.com/ecosystem/documentation/natural/nat425mf/sm/readwork.htm%5B/url%5D)), but here’s the short version. Start with some data definitions. ```auto DEFINE DATA LOCAL 1 #FIELDS 2 #NAME (A25) 2 #ADDRESS (A25) 2 #SALARY (P9.2) 2 #AGE (N2) 1 REDEFINE #FIELDS 2 #BLOCK (A58) 1 #OTHER 2 #AMOUNT (P7.2) 2 #ALPHA (A10) END-DEFINE ``` The “vast majority” of examples that you see should be either ```auto R1. READ WORK 1 RECORD #FIELDS END-WORK ``` or ```auto R2. READ WORK 1 #BLOCK END-WORK ``` In the R1 loop, a list of fields is read. The RECORD option tells Natural not to verify the contents of numeric fields, so this will execute faster than with the default SELECT clause. (How much faster is dependent on the number of numeric fields.) In the R2 loop, a single alpha field is read, so the negative effect of the SELECT clause on execution time will be minimal (likely unnoticeable, even for large files). Adding the RECORD clause would help, but not much. At compile time, the group name #FIELDS is translated into a list of contiguous fields. If the fields are not contiguous in memory, the SELECT clause must be used. ```auto R3. READ WORK 1 #NAME #AGE #AMOUNT END-WORK * R4. READ WORK 1 RECORD #NAME #AGE #AMOUNT END-WORK ``` R3 will execute, but R4 will not even compile. ---
**Author:** ![Steve\_Robinson](https://sea1.discourse-cdn.com/techcommunity/user_avatar/techcommunity.softwareag.com/steve_robinson/32/107_2.png) [@Steve\_Robinson](https://techcommunity.softwareag.com/u/Steve_Robinson)\ **Post date:** [January 20, 2009, 6:08pm UTC](https://techcommunity.softwareag.com/t/a-basic-question-about-workfiles-and-type-checking/79964/3 "2009-01-20T18:08:56Z")
The documentation for READ WORK FILE has always been a bit misleading. For example, "If RECORD is specified, all fields in each record read are made available for processing. An operand list (operand1) corresponding to the layout of the record must be provided. " The above statement seems to indicate that the operand list for the RWF must be the same as for the WWF that created the record (and I have found this interpretation at a large percentage of the shops where I have taught Natural). That this is not true can be seen below: DEFINE DATA LOCAL 1 #REC 2 #A (A3) 2 #B (A6) 2 #C (A5) \* 1 #RECORD (A14) INIT \<‘AAAAABBBBBBBCC’\> \* 1 #AA (A4) INIT \<‘AAAA’\> 1 #BB (A3) INIT \<‘BBB’\> 1 #CC (A5) INIT \<‘CCCCC’\> END-DEFINE \* INCLUDE AASETCR INCLUDE AATITLER \* WRITE WORK FILE 1 #AA #BB #CC \* READ WORK FILE 1 RECORD #REC /\* #A #B #C OR #AA #BB #CC WRITE 5T ‘=’ #AA ‘=’ #BB ‘=’ #CC // 5T ‘=’ #REC // 5T ‘=’ #A ‘=’ #B ‘=’ #C LOOP \* END ``` PAGE # 1 DATE: JAN 20, 2009 PROGRAM: RWF01 LIBRARY: INSIDE #AA: AAAA #BB: BBB #CC: CCCCC #REC: AAA ABBBCC CCC #A: AAA #B: ABBBCC #C: CCC ``` You do not even need the same number of fields in the list for RWF; as shown below DEFINE DATA LOCAL 1 #REC 2 #A (A3) 2 #B (A6) _2 #C (A5) 1 #RECORD (A14) INIT \<‘AAAAABBBBBBBCC’\> \* 1 #AA (A4) INIT \<‘AAAA’\> 1 #BB (A3) INIT \<‘BBB’\> 1 #CC (A5) INIT \<‘CCCCC’\> END-DEFINE \* INCLUDE AASETCR INCLUDE AATITLER \* WRITE WORK FILE 1 #AA #BB #CC \* READ WORK FILE 1 RECORD #REC / #A #B #C OR #AA #BB #CC WRITE 5T ‘=’ #AA ‘=’ #BB ‘=’ #CC // 5T ‘=’ #REC // 5T ‘=’ #A ‘=’ #B /_ ‘=’ #C LOOP \* END PAGE # 1 DATE: Jan 20, 2009 PROGRAM: RWF02 LIBRARY: INSIDE ``` #AA: AAAA #BB: BBB #CC: CCCCC #REC: AAA ABBBCC #A: AAA #B: ABBBCC ``` Now for some fun. Go back to the first program, RWF01 and change the RWF statement as shown below: READ WORK FILE 1 RECORD #A #B #C /\*OR #AA #BB #CC This will not compile, even though #REC is the Group Name for the three fields #A #B and #C. This is the one place in Natural (so far as I know) where a Group Name is not an abbreviation for several field names. In version 1 of Natural and I seem to recall 2.1 a well, you could not have a group name in a RWF RECORD. The reason is quite simple. RWF RECORD does not “pay attention” to fields. At compile time it basically looks at the argument (single variable or group name) to figure out a starting address and a length. At execution time it picks up the appropriate number of characters from a record and “plops” it down at the start address. I guess that many users wanted to be able to have a RWF and a WWF with the same Group name, hence the syntax change was made. In the WWF the group name is indeed an abbreviation, in RWF RECORD the group name plays a role at compile time, but not at execution time. This can get very confusing when Group Arrays are involved. Thus: 1 #group (3) 2 #a (a3) 2 #b (a3) 2 #c (a3) WWF #group (_) followed later by RWF RECORD #group (_) will not do what you might expect it would. Later today I will post an article from Inside Natural, on the Natural Basics - Inside Natural thread, that describes what happens. steve ---
**Author:** ![system](https://global.discourse-cdn.com/techcommunity/original/3X/c/d/cd19967bb605d28a72d77eb83a1cae22f3df2eb8.svg) [@system](https://techcommunity.softwareag.com/u/system)\ **Post date:** [April 2, 2021, 2:51pm UTC](https://techcommunity.softwareag.com/t/a-basic-question-about-workfiles-and-type-checking/79964/4 "2021-04-02T14:51:22Z")