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Home GeoPack GeoDB Methods RetrieveBLOB | |||||||||||
See also: AddBLOB, TgdbItem | |||||||||||
RetrieveBLOB |
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The method RetrieveBLOB retrieves binary data from the database and stores it either in a file (version [1]), or in a memory structure [2], or in a memory stream [3]. The parameter DBEntry addresses the database entry (DBEntry may take values between 1 and NumEntries). RetrieveBLOB returns a TRUE value if any binary data is available for the specified database entry. The variable parameter MetaInfo contains the meta information about the BLOB. Overloaded version [1] - retrieve to file: The parameter FilePath specifies the destination file which is created when retrieving the binary data. Depending on whether FilePath contains a valid filename or only a path, RetrieveBLOB stores the data using either the FilePath parameter or the original filename (which is contained in Data[DBEntry].Name). Thus you can retrieve the BLOB using its original filename without even knowing it (if the database entry type is gitFileBlob).
Overloaded version [2] - retrieve to memory structure: The method RetrieveBLOB retrieves binary data from the database and copies it to the data structure referred to by PBLOBData. SizeOfBLOBData specifies the size of this data structure. Overloaded version [3] - retrieve to memory stream: This version of RetrieveBLOB retrieves the BLOB data and copies it into the stream BlobStream. Any previous data in the variable BlobStream is overwritten.
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