The Update Field command allows a single field in a data base file to
be changed to a specified value. Either all records are changed or
you may specify a simple selection criteria.
A typical command would be:
UPDFLD FILE(xxx) +
SELFLD(FLDB) SELOP(*EQ) SELVAL(XYZ)
UPDFLD(FLDC) UPDVAL(ABC)
This would select any records where FLDB is equal to XYZ. The field
FLDC would be updated to a value of ABC.
An audit entry is sent to the QAUDJRN if it exists. If not, a
message is sent to QSYSOPR to provide an audit trail that UPDFLD was
used.
You should consider the command is to be specified as:
- If the selection criteria is true
- Update the specified field
The SELOP parameter supports the normal functions of *EQ, *GE, *GT,
*LE, *LT, and *NE. *CT (contains) is also supported.
You can also use the command without selection such as:
UPDFLD FILE(FLDZ) UPDFLD(yyy) UPDVAL(ABC)
All records in the first member of the file would be changed for the
field FLDZ to a new value of ABC.
You must have *ALL authority to the file to use UPDFLD. This
normally restricts the command to a user who either has *ALLOBJ
special authority or owns the file.
UPDFLD can be helpful when adding a new field to a file and you want
to initialize it for all records to a specific value or when you must
perform a simple maintenance function.
The file is always processed in arrival sequence.
Two special values *BLANKS and *ZEROS may be specified for either the
SELVAL or UPDVAL parameter. This allows a field to be set to blanks
or zeros or a records may be selected for update if a field contains
a value of blanks or zeros. For example, specifying UPDVAL(*ZEROS)
may be helpful to reset 'year to date' fields at the beginning of the
year.
If a character or variable length field is described, the UPDVAL
value is moved from the left into the field and the remainder of the
field is blanked out. If a variable length field is updated, the
actual length of the data is used to update the leading two bytes of
the internal field. A maximum size character field of 50 bytes is
supported.
If a decimal field is described (packed, zoned, or binary), the
UPDVAL value must be all digits and the same number must exist as is
defined for the field. For example, if the field is declared as *DEC
LEN(5 0), 5 digits must be entered. To set the field to a value of
30, you would specify:
UPDVAL(00030)
A similar convention is used with the SELVAL parameter. To select a
field that is declared as *DEC LEN(5 2) for a value of 50.00 you
would specify:
SELVAL(05000)
Command parameters *CMD
------------------
FILE The qualified file name of the file. The library
value defaults to *LIBL. *CURLIB may also be
specified.
A physical file or logical file with a single format
may be specified.
SELFLD The field name in the file to select on. Only the
types character, variable length, packed, zoned, or
binary are supported. A character field cannot
exceed 50 bytes in length.
SELOP The operation to be used for selection. The default
is *EQ. The other values that may be specified are
*GE *GT *LE *LT, *NE or *CT (contains). The *CT
function scans the field in the record for the
select value. *CT is limited to character or
variable length fields. The length of the select
value as determined by the last non-blank is used to
limit the scan.
SELVAL The value of the selection field to cause the record
to be updated.
The special value *BLANKS may be entered (beginning
in position 1) to select on a blank value.
If the selection field is declared as a decimal
type, the value must match in terms of number of
digits and only digits may be entered. An error
message will occur if the exact number of digits
entered does not agree with the field definition.
The value is tested appropriately depending on the
type of packed, zoned, or binary. The special value
*ZEROS may be entered (beginning in position 1) to
test for zeros in the selection field.
UPDFLD The field name in the file to be updated. Only the
types character, variable length, packed, zoned, or
binary are supported. A character field cannot
exceed 50 bytes in length.
UPDVAL The value to be assigned to the field. For a
character field, the data is moved beginning with
the leftmost byte of the value to the leftmost byte
of the field. Any remaining characters are blanked
out.
The special value *BLANKS may be entered (beginning
in position 1) to blank out the entire field.
For a decimal field, the value must match in terms
of number of digits and only digits may be entered.
An error message will occur if the exact number of
digits entered does not agree with the field
definition. The value is moved appropriately
depending on the type of packed, zoned, or binary.
The special value *ZEROS may be entered (beginning
in position 1) to zero out the field.
MBR The member of the file to be updated. The default
is *FIRST.
Restrictions
------------
Several restrictions are stated throughout such as:
** You must have *ALL authority to the file.
** A maximum of a 50 byte field character field may be named.
** Multi-format logical files are not supported.
** If a decimal field is to be selected on to be updated, the
exact number of digits must be entered.
** A file which allows null values is not supported.
Prerequisites
-------------
The following TAA Tools must be on your system:
EDTVAR Edit variable
RTVFLDA Retrieve field attributes
HLRMVMSG HLL Remove message
RTVVALA Retrieve value attributes
SNDAUDE Send audit entry
SNDCOMPMSG Send completion message
SNDESCMSG Send escape message
SNDSTSMSG Send status message
Implementation
--------------
None, the tool is ready to use.
Objects used by the tool
------------------------
Object Type Attribute Src member Src file
------ ---- --------- ---------- ----------
UPDFLD *CMD TAADBHK QATTCMD
TAADBHKC *PGM CLP TAADBHKC QATTCL
TAADBHKR *PGM RPG TAADBHKR QATTRPG
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