Solved

Databases, Blob - How do I access?

Posted on 1998-08-27
7
311 Views
Last Modified: 2010-04-10
How can I access my Blob Field I created.  I want to store/retrieve 1024 Bytes.  But I just seem to be too clumsy too store or retrieve anything from it (newbie-experience).

I'm working with C++B 3 on a Paradox 7 Table.

Thx
0
Comment
Question by:Odie
  • 4
  • 2
7 Comments
 
LVL 2

Expert Comment

by:duneram
ID: 1171438
I use the Borland Database Engine.  Get your hands on a copy of it.  It comes with the api and documentation for you to build classes for tables so you can get and put to a blob in a painless manner.  try www.inprise.com

Go to http://www.inprise.com/searchsite/
and enter 'Frameworks'  and check the Borland Database Engine checkbox

Then press search.
0
 
LVL 2

Expert Comment

by:duneram
ID: 1171439
Another decent reference at that site:

http://www.inprise.com/devsupport/bde/cppfiles.html
0
 
LVL 1

Author Comment

by:Odie
ID: 1171440
Um...  I should have mentioned that I'm using the BDE too.  But I'm too stupid too handle the TBlobField.

MyTable->FieldByName("MyBlobField")->...

then what do I do with this?
0
Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

 
LVL 2

Expert Comment

by:duneram
ID: 1171441
I'll look into it!!  Do you use the frameworks code generator?
0
 
LVL 1

Author Comment

by:Odie
ID: 1171442
I don't know what it is.  (Guess I don't then.)
0
 
LVL 2

Expert Comment

by:duneram
ID: 1171443
I'll take a look this weekend...  oh i forgot I am going to be out of town this weekend. I guess I have to wait until monday.  HOpefully someone else will beat me and post your answer here.

In the mean time take a look at any of these functions in your documentation:

DbiAppendRecord: Appends a record to the end of the table associated with the given cursor.
DbiDeleteRecord: Deletes the current record of the given cursor.
DbiFreeBlob: Closes the BLOB handle located within the specified record buffer.
DbiGetBlob: Retrieves data from the specified BLOB field.
DbiGetBlobHeading: Retrieves information about a BLOB field from the BLOB heading in the record buffer.
DbiGetBlobSize: Retrieves the size of the specified BLOB field in bytes.
DbiGetField: Retrieves the data contents of the requested field from the record buffer.
DbiGetFieldDescs: Retrieves a list of descriptors for all the fields in the table associated with the cursor.
DbiGetFieldTypeDesc: Retrieves a description of the specified field type.
DbiInitRecord: Initializes the record buffer to a blank record according to the data types of the fields.
DbiInsertRecord: Inserts a new record into the table associated with the given cursor.
DbiModifyRecord: Modifies the current record of table associated with the cursor with the data supplied.
DbiOpenBlob: Prepares the cursor's record buffer to access a BLOB field.
DbiPutBlob: Writes data into an open BLOB field.
DbiPutField: Writes the field value to the correct location in the supplied record buffer.
DbiReadBlock: Reads a specified number of records (starting from the next position of the  cursor) into a buffer.
DbiSaveChanges: Forces all updated records associated with the cursor to disk.
DbiSetFieldMap: Sets a field map of the table associated with the given cursor.
DbiTruncateBlob: Shortens the size of the contents of a BLOB field, or deletes the contents of a BLOB field from the record, by shortening it to zero.
DbiUndeleteRecord: Undeletes a dBASE record that has been marked for deletion (a "soft"  delete).
DbiVerifyField: Verifies that the data specified is a valid data type for the field specified, and that all validity checks in place for the field are satisfied. It can also be used to check if a field is  blank.
DbiWriteBlock: Writes a block of records to the table associated with the cursor.


0
 
LVL 1

Accepted Solution

by:
cph earned 50 total points
ID: 1171444
You can only read/write and do some basic file operation on a BLOB as the DB doesn't know anything about its content. What you could do is set a field in your table run an SQL query based on that field then retrieve it.

Hope this help,

CpH
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In days of old, returning something by value from a function in C++ was necessarily avoided because it would, invariably, involve one or even two copies of the object being created and potentially costly calls to a copy-constructor and destructor. A…
Container Orchestration platforms empower organizations to scale their apps at an exceptional rate. This is the reason numerous innovation-driven companies are moving apps to an appropriated datacenter wide platform that empowers them to scale at a …
The goal of the video will be to teach the user the difference and consequence of passing data by value vs passing data by reference in C++. An example of passing data by value as well as an example of passing data by reference will be be given. Bot…
The viewer will learn how to clear a vector as well as how to detect empty vectors in C++.

920 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

14 Experts available now in Live!

Get 1:1 Help Now