Foxpro 2.6 commands with example update#
Foxpro 2.6 commands with example code#

REPLACE sometable.somefield WITH somevalue If Contacts is not the current alias, this syntax can lead to unexpected results.

Foxpro 2.6 commands with example code#

Just recently, I debugged someone else's code that used this construct.

REPLACE contacts.firstname WITH 'Mike', contacts.lastname WITH 'Yearwood' So, after testing, go back and reformat your REPLACEs to use one line, because it is faster. However, if each REPLACE is a separate line, the error will occur on that specific line. and a data type mismatch on a single line REPLACE with a dozen or so fields doesn't help you. Of course, during development you may wish to keep the REPLACE of each field separate, since in the prior example the REPLACE is one line. Still, especially in loops or with large numbers of records to update, debug the code like this, but recombine the code later. However, when using complex expressions, it's sometimes easier to write the code in single expressions like this. Timing shows the two commands above take longer than the single command.

Foxpro 2.6 commands with example update#

While this will obviously produce the same result, it's my belief that VFP must be reading the record into memory, updating the specified field with the specified data and then posting this update back to the table. The following are alternatives that work with comments on why they should be avoided. ImportTable.Field3 WITH 'Smith' & Last Name - Peter Crabtree ImportTable.Field2 WITH 'Q', & Middle Initial ImportTable.Field1 WITH 'Peter', & First Name While it could be hard to read, what is easier, exactly? Here's an example of how it could possibly be made easier to read: However, according to VFP help, 'You cannot place & and a comment after the semicolon used to continue a command line to an additional line.' This is quite definitely false, in VFP 6, 7, and 8. I recall reading somewhere that VFP started supporting that with VFP 6. The example shown doesn't print nicely here on Wiki, and it is overkill in my opinion, but the comment beside 'two' can be most enlightening in later work.

As regards 'much harder to read', that is highly debatable and subjective. LastName with 'three' & Person's Last NameДЄctually that capability came with FPD 2.6 I believe. MiddleInitial with 'two', & Added Jan 4, 2003 REPLACE FirstName with 'One', & Person's First Name I would advise against it because it makes code much harder to read. It probably worked in some earlier sp's and maybe VFP5, but I'm almost certain not in VFP3) you can add comments on each line of the replace: While upgrading a FoxPro 2.6 app to VFP9, I discovered the comma is NOT needed! And probably hasn't been needed since 2.6 ! Think of how many commas (in bytes) we've wasted! Craig RobertsДЄ benefit to this method is that (in VFP6sp5 and newer. I find each part of the command easier to read this way especially when complex expressions are used. I format the command to permit me to reorganize the field sequence if needed. REPLACE field1 WITH expression1, field2 WITH expression2 REPLACE field1 WITH expression1, field2 WITH expression2 Scope Clauses IN alias If you attempt to REPLACE more than 128 fields in a single command, it will generate a Syntax Error - Mike Yearwood I didn't find this documented in the VFP 7.0 or 8.0 help files or a few other places I looked. REPLACE apparently has a limitation of REPLACEing only up to 128 fields in a single command. and even multiple related tables simultaneously. It can operate on a specified record, the current record, a range of records ( Scope Clauses) or a set of records (FOR Contactdate = DATE()).

The REPLACE command lets you fill in a set of fields with specified values.