An
item of type BLOB represents a binary large object with a length ranging from
one byte to two gigabytes.
The following statements are true of an
item of type BLOB:
- It can be declared only as an individual item, and is not supported in
BasicRecords.
- It can be passed to local function and program calls. Large object parameters
and corresponding arguments must both be declared as large objects of the
same type.
- It can be assigned only to another Blob variable.
- It can be moved to another Blob variable, which has the same result as
being assigned to a Blob variable.
- You can create a reference variable of BLOB.
- It uses SQLlocator (BLOB); that is, BLOB contains a logical pointer to
the SQL BLOB data rather than to the data itself.
- When used with SQLRecord,
- BLOB represents Binary Large Object as a column in the database.
- BLOB is valid for the duration of the transaction in which
it was created.
- It cannot be passed to calls to remote programs or to non-EGL programs.
- It cannot be referenced as an operand on assignment statements or in expressions.
You may use the following functions with BLOB:
- attachBlobToFile
- freeBlob
- getBlobLen
- loadBlobFromFile
- truncateBlob
- updateBlobToFile