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The Pier Shareware 6
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The_Pier_Shareware_Number_6_(The_Pier_Exchange)_(1995).iso
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BDEMO010.TXT
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1994-10-27
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BUILDER DATABASE FUNCTIONS
The Builder Database Functions are a Flexible and Easy to Use Set of
Clipper UDFs Designed to Add/Change/Delete Database Records.
One of the features that make them so easy to use is the ability to
Add or Change databases one record at a time. This is an advance
over the normal xBase style of one FIELD at a time database I/O.
The way this is achieved is to create a STATIC array of field values for
every database in your application. A corresponding manifest constant entry
is made in a Header (.CH) file for every database field in your application
also. The manifest constant is created by prefixing it with an alphabetic
character. For example, the database field CITY could become the manifest
constant ACITY. This method provides both readable source code and efficient
access to database data.
The Builder Save_It() function requires four parameters in order to
Add/Change/Delete/ or Recall a database record. When adding a record
you can (optionally) use the deleted records of your database as
"Add Space" when using the Save_It() function. That way recycling
your deleted records instead of APPENDing BLANK to add a record.
Using this feature requires that SET DELETED ON is active (Builder
default) and that each database to use this feature has an open
index created like: INDEX ON IF(DELE(),"*"," ") TO ... This uses one
valuable file handle per database; but the ease of maintaining data
integrity and NEVER-EVER having to PACK these databases makes this
an excellent solution for network database systems.
Other Builder database functions do your file maintenance chores for
you, including maintaining related databases. Do indexed searches with
ISeek(), Browse databases with Plist(). Use Fld_Repl() instead of
REPLACE when only a few fields need to be updated. Fld_Repl() locks
and unlocks records when used on a network.
View the samples and look at the source code, this stuff REALLY works.
Also see the following functions in the Builder library documentation:
DbStor() - Store database fields to memory variables.
Fil_Lock() - Lock an entire database.
The following functions are in the Builder library, but are used
internally only and should not be required in any other way.
DbRepl() - Replace a database record with memory variables.
Add_Rec() - Append a Database Record, Network Aware
Net_Use() - Called by Open_Fil() after error testing.
Opens a database.
Rec_Lock() - Lock a database record.
End of File ***