Subject |
Re: DBase IV Commands |
From |
Mervyn Bick <invalid@invalid.invalid> |
Date |
Sun, 22 May 2016 08:32:37 +0200 |
Newsgroups |
dbase.getting-started |
On 21/05/2016 18:55, Marilyn Price wrote:
> Actually, Ken, it's a little more complicated than that, as dBase IV
> didn't have any alter table commands.
>
> In a program:
> use oldtable
> copy to temp sdf
> copy structure to <some new name>
That should actually be
copy structure extended to <new name>
This created a four field table with fields
FIELD_NAME,FIELD_TYPE,FIELD_LEN and FIED_DEC. The table had a record
for each field in the original table.
> use <some new name>
> locate for fieldname = "oldfieldname"
> replace fieldname with "newfieldname"
As you later pointed out one needed to create a new table from the
structure extended table before appending the data. I can't remember if
this would overwrite the existing table or not. One probably had to
erase the old table first.
erase <original table name.dbf)
create <original table> from <new name>
use <original table.
> append from temp sdf
If one was changing field widths the data would need to be saved in .csv
form rather than SDF form.
Removing a field in a program was even more work. It entailed creating
a normal table (from a structure extended table) with the field to be
remove at the end of the record. A normal append would place named
field in named field even if the field order differed. One could then
export the data and create a new table with the new fields.
From the dot prompt modi stru tablename would do the job.
Mervyn.
>
> Should do it. However, this is strictly from memory as I no longer have
> dBase IV installed and haven't had for over a decade....
>
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