Easytrieve FIELD

What Counts as a Field

Any symbol defined by FILE line, DEFINE line, or provided by the product as system field. Each field has storage: bytes in a record, working storage block, or static area. Attributes from definition determine how assignments convert values and how reports edit output. Undefined names in JOB logic produce compile errors—compiler enforces define-before-use.

Field Naming Rules

Length one through 128 characters. Start with letter, digit, or # @ $. Not all digits. No delimiters inside name. Case sensitivity follows site and compiler options—treat names as case-sensitive for safety. Hyphens improve readability in column listings: PAY-GROSS versus PAYGROSS. Apostrophes inside names are invalid—training manual warns EMP'L-NO fails; use EMP-NO instead.

Qualified Field References

When multiple files define EMPNO, qualify with file name: PERSNL:EMPNO versus ARCHIVE:EMPNO. Qualifier disambiguates for compiler and readers. Unqualified EMPNO when both exist is error or ambiguous resolution depending on context. Macros generating standard layouts should document which file owns canonical field definitions.

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IF PERSNL:DEPT EQ '911'
   PRINT DETAIL-RPT
END-IF
 
WS-NET = PERSNL:GROSS - WS-TAX

Parent and Overlay Fields

Parent field owns absolute position in FILE. Child overlay reuses parent bytes with optional +offset. LAST-NAME NAME 8 A is child of NAME 17 16 A—starts byte one of parent in overlay syntax. Both names are independent fields for IF and LINE—changing LAST-NAME bytes changes corresponding bytes in NAME. Order in source: define parent before children.

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NAME          17 16 A
  LAST-NAME     NAME  8 A
  FIRST-NAME    NAME +8 8 A
 
DATE-OF-HIRE 136  6 N
  HIRE-MM       DATE-OF-HIRE     2 N
  HIRE-DD       DATE-OF-HIRE  +2  2 N
  HIRE-YY       DATE-OF-HIRE  +4  2 N

Working Storage and Static Fields

Fields with location W or S are not FILE record columns—they exist only in program memory. WS-TAX W 5 P 2 is field holding tax amount for current calculation. CURR-DATE S 6 N is field holding run date. Referencing them in LINE prints computed values, not file columns unless you copy file data into them first.

System Fields

SYSDATE, SYSTIME, and other reserved names supply environment values without DEFINE. Appear in TITLE COL SYSDATE and GETDATE macro assignments. Do not DEFINE your own field named SYSDATE—conflicts with system symbol. Consult system variables section for full list per release.

Fields in Expressions

Arithmetic uses numeric fields as operands. IF uses fields in relational and class conditions. Assignment left side must be valid receive field—often working storage or FILE field with UPDATE permission. Right side may combine fields and literals. Type of receive field drives conversion rules from send field or literal.

Fields on Reports

LINE DEPT LAST-NAME GROSS lists field names whose HEADING and MASK defaults apply. Quantitative fields with decimals participate in SUM when named in SUM statement. Control breaks use CONTROL fieldname—field should be sort-aligned in input. Undefined LINE field is compile error.

VARYING and Array Fields

VARYING fields have variable active length tracked separately. OCCURS fields repeat fixed layout—index field selects element. Both are still fields with names—subscript syntax documented in programming reference for your release.

Enterprise Naming Discipline

• Prefix working storage with WS- or work- shop standard.
• Match copybook names exactly for FILE fields—no creative renaming.
• Document overlay children in data dictionary comments.
• Avoid duplicating glossary terms with different spellings across programs.
• Centralize FILE layouts in macros for single source of truth.

Field vs Record vs File

File is dataset PERSNL. Record is one row read by JOB INPUT. Field is one column within record—DEPT, GROSS, NAME. Easytrieve blurs record boundary when multiple FILE definitions share buffer—qualifiers keep fields straight. Beginners saying update the file when they mean assign GROSS field should use precise vocabulary in design documents.

Common Field Mistakes

1. Typo in field name—logic updates undefined or wrong field.
2. Unqualified name with duplicate across files.
3. Overlay offset wrong—child reads wrong parent bytes.
4. Using FILE field before READ populates record buffer.
5. Redefining reserved system field name.

Explain It Like I'm Five

A field is a labeled drawer in a filing cabinet. The label is the name you type in code. Some drawers are in the big cabinet that arrives from the computer file; some are on your desk for scratch paper. If two cabinets have drawers with the same label, you must say which cabinet before opening the right drawer.

Exercises

1. Write NAME with LAST-NAME and FIRST-NAME overlays.
2. Reference qualified PERSNL:DEPT in IF statement.
3. List three invalid field names and why.
4. Explain parent vs overlay field relationship.
5. Name one system field and typical use.