Blob sizes in mySql

Question

MySQL supports different blob sizes. I'm told that kodo does not support
blobs in MySQL however I can override this by extending the MySQLDictionary
class.
This is what I was told.....
"package com.xyz;
import java.sql.*;
import kodo.jdbc.schema.*;
import kodo.jdbc.sql.*;
public class CustomMySQLDictionary
extends MySQLDictionary
protected String appendSize (Column col, String typeName)
if (col.getType () == Types.BLOB && col.getSize () > 0)
return <sized blob string>
return super.appendSize (col, typeName);
Plug your dictionary into Kodo with:
kodo.jdbc.DBDictionary: com.xyz.CustomMySQLDictionary
In your metadata, set the size of your field with:
<field name="blobField">
<extension vendor-name="kodo" key="jdbc-size" value="xxx"/>
</field>
I have done this with a couple of minor changes. It almost does what I
need it to do.
Basically I want to create an ANT script which will enhance the necessary
files, create my database, and then dump the schema to a file(so that I
can have a sql script to run later). I have everything working with the
exception of the of creating the database. The database gets created
however the column where I specify blob, still gets created as a blob. I
want to use a different blob size.
The above code helped me with dumping the schema to a file and dumps the
appropriate data as I would expect it.
So how do I get the database created properly? Also, is there a way to
automatically generate the schema without actually creating the database
first?

Answer 1

Mike Krell wrote:
MySQL supports different blob sizes. I'm told that kodo does not support
blobs in MySQL however I can override this by extending the MySQLDictionary
class.
This is what I was told.....
"package com.xyz;
import java.sql.*;
import kodo.jdbc.schema.*;
import kodo.jdbc.sql.*;
public class CustomMySQLDictionary
extends MySQLDictionary
protected String appendSize (Column col, String typeName)
if (col.getType () == Types.BLOB && col.getSize () > 0)
return <sized blob string>
return super.appendSize (col, typeName);
Plug your dictionary into Kodo with:
kodo.jdbc.DBDictionary: com.xyz.CustomMySQLDictionary
In your metadata, set the size of your field with:
<field name="blobField">
<extension vendor-name="kodo" key="jdbc-size" value="xxx"/>
</field>
I have done this with a couple of minor changes. It almost does what I
need it to do.
Basically I want to create an ANT script which will enhance the necessary
files, create my database, and then dump the schema to a file(so that I
can have a sql script to run later). I have everything working with the
exception of the of creating the database. The database gets created
however the column where I specify blob, still gets created as a blob. I
want to use a different blob size.
The above code helped me with dumping the schema to a file and dumps the
appropriate data as I would expect it.
So how do I get the database created properly? Also, is there a way to
automatically generate the schema without actually creating the database
first?After doing some further investigation, the call "col.getType ()" returns
a Types.VARBINARY and not a Types.BLOB. So I changed my code to test for
this instead and also test for the column size to indicate the appropriate
BLOB size. Is this correct?
It appears that a LONGBLOB is coming back as a "LONG VARBINARY", even
though I am testing for this, I cannot get a LONGBLOB. Why?
Also, prior posts indicate that BLOBs are not supported in Kodo and MySQL.
I'm confused as to what this means because in the src files that you
delivered with your product, I see references to BLOB, MEDIUMBLOB, etc.
The file I'm referring to is kodo.jdbc.sql.MySQLDictionary. So tell me
again why blobs aren't supported?