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ptyagi108 / mesh4x

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MsAccess adapter support Autonumeric ReplicationID #117

Open GoogleCodeExporter opened 9 years ago

GoogleCodeExporter commented 9 years ago 
Support Auto numeric ReplicationID

Original issue reported on code.google.com by jtondato@gmail.com on 22 Jun 2009 at 5:13

GoogleCodeExporter commented 9 years ago 
MsAccess 2000 adapter is available (based on Jackcess library).
For other formars we are testing commercial drivers (hxtt).

Original comment by jtondato@gmail.com on 30 Jun 2009 at 3:20

GoogleCodeExporter commented 9 years ago 
we are waiting for response of hxtt support team, the issue is how to create a 
UUID 
from the binary obtained for GUIDs fields.

Original comment by jtondato@gmail.com on 3 Jul 2009 at 3:27

GoogleCodeExporter commented 9 years ago 
MsAccess represents the GUID as byte[16] 128 bits, the first 8 bytes (64 bits) 
are 
the most significant bits of the guid and the last 8 bytes (64 bits) are the 
least 
significant bits of the guid. 

For Read a GUID:

                byte[] bytes= ...;   // bytes read form result set

        byte[] bytesMostSignificant = new byte[8];
        bytesMostSignificant[0] = bytes[3];
        bytesMostSignificant[1] = bytes[2];
        bytesMostSignificant[2] = bytes[1];
        bytesMostSignificant[3] = bytes[0];

        bytesMostSignificant[6] = bytes[7];
        bytesMostSignificant[7] = bytes[6];
        bytesMostSignificant[4] = bytes[5];
        bytesMostSignificant[5] = bytes[4];

        Long mostSignificant = ByteBuffer.wrap(bytesMostSignificant).getLong
();

        byte[] bytesLestSignificant = new byte[8];
        bytesLestSignificant[0] = bytes[8];
        bytesLestSignificant[1] = bytes[9];
        bytesLestSignificant[2] = bytes[10];
        bytesLestSignificant[3] = bytes[11];
        bytesLestSignificant[4] = bytes[12];
        bytesLestSignificant[5] = bytes[13];
        bytesLestSignificant[6] = bytes[14];
        bytesLestSignificant[7] = bytes[15];

        Long leastSignificant = ByteBuffer.wrap(bytesLestSignificant).getLong
();
        UUID uuid = new UUID(mostSignificant, leastSignificant);

For Write a GUID:

        UUID uuid = ....;   // application guid to save

        long mostSignificantBits = uuid.getMostSignificantBits();

        ByteArrayOutputStream mostSignificantBAOS = new ByteArrayOutputStream
();
        DataOutputStream mostSignificantDOS = new DataOutputStream
(mostSignificantBAOS);
        mostSignificantDOS.writeLong(mostSignificantBits);
        mostSignificantDOS.flush();

        byte[] mostSigBytes = mostSignificantBAOS.toByteArray();

        long leastSignificantBits = uuid.getLeastSignificantBits();
        ByteArrayOutputStream leastSignificantBAOS = new 
ByteArrayOutputStream();
        DataOutputStream leastSignificantDOS = new DataOutputStream
(leastSignificantBAOS);
        leastSignificantDOS.writeByte(mostSigBytes[3]);
        leastSignificantDOS.writeByte(mostSigBytes[2]);
        leastSignificantDOS.writeByte(mostSigBytes[1]);
        leastSignificantDOS.writeByte(mostSigBytes[0]);
        leastSignificantDOS.writeByte(mostSigBytes[5]);
        leastSignificantDOS.writeByte(mostSigBytes[4]);
        leastSignificantDOS.writeByte(mostSigBytes[7]);
        leastSignificantDOS.writeByte(mostSigBytes[6]);
        leastSignificantDOS.writeLong(leastSignificantBits);
        leastSignificantDOS.flush();

        byte[] bytes = leastSignificantBAOS.toByteArray();  // bytes to 
write in result set

Original comment by jtondato@gmail.com on 7 Jul 2009 at 7:09