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how to read data from db file

 
Jofer Chan
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Posts: 49
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hi,everyone:
The format of data in the database file is as follows:
Start of file
4 byte numeric, magic cookie value identifies this as a data file
4 byte numeric, offset to start of record zero
2 byte numeric, number of fields in each record
Schema description section.
Repeated for each field in a record:
2 byte numeric, length in bytes of field name
n bytes (defined by previous entry), field name
2 byte numeric, field length in bytes
end of repeating block
Data section. (offset into file equal to "offset to start of record zero" value)
Repeat to end of file:
2 byte flag. 00 implies valid record, 0x8000 implies deleted record
Record containing fields in order specified in schema section, no separators between fields, each field fixed length at maximum specified in schema information
End of file
All numeric values are stored in the header information use the formats of the DataInputStream and DataOutputStream classes. All text values, and all fields (which are text only), contain only 8 bit characters, null terminated if less than the maximum length for the field. The character encoding is 8 bit US ASCII.
how to write codes to read data from db file?
 
Andrew Monkhouse
author and jackaroo
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Hi Jofer,
I would recommend you look at the Sun tutorial on IO, particularly the RandomAccessFile section.
When you are comfortable with the standard I/O classes, you may wish to look at the New I/O APIs (NIO) which give some benefits over RandomAccessFile.
Regards, Andrew
 
Siju Odeyemi
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Originally posted by Jofer Chan:
how to write codes to read data from db file?

Hmmm.. I'm a little perplexed by this db file as well. I have just bought and downloaded my assignment. I'll take a closer look and share my thoughts here soonish.
 
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