Text truncated to 255 chars with ODBC

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I am using an ODBC connection to a MS Access database.
When using a SELECT statement and collecting the data via php ODBC functions, I find that the data from TEXT fields is truncated to 255 characters.
The texr fields are up to 1400 chars in length and some contain HTML tags,
but the maximum length returned is 255.
Any insight appreciated

[Motoma]

I am using an ODBC connection to a MS Access database.
When using a SELECT statement and collecting the data via php ODBC functions, I find that the data from TEXT fields is truncated to 255 characters.
The texr fields are up to 1400 chars in length and some contain HTML tags,
but the maximum length returned is 255.
Any insight appreciated

Check the value of odbc.defaultlrl . This may be causing truncation is set low.

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Thanks Motoma, already found that suggestion in php manual.
Tried [PHP]ini_set ('odbc.defaultl rl','65536');[/PHP]Had no effect.

Bill Gates 1 TSDN 0

[Motoma]

Thanks Motoma, already found that suggestion in php manual.
Tried [PHP]ini_set ('odbc.defaultl rl','65536');[/PHP]Had no effect.

Bill Gates 1 TSDN 0

I've been doing some Googling because your problem perplexed me. Take a look at this link, specifically the example output for a TEXT column.

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Thanks again Motoma. had a look at the article and the following article seems to confirm our fears.
http://support.microsoft.com/kb/214854
So it seems to be a Jet problem. I am copying the data into a MySql DB
Apparently you are supposed to chunk the data in by CHAR size bundles of 255 bytes.
Don't fancy writing the code for that.
May have a look at other type connections, ADO possibly, but only used this with Visual Basic, never php.

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Just noticed the maximum size of an Access TEXT field is 255.
They are MEMO fields that I am reading not TEXT fields.
Hope this hasn't mislead anybody.
The same problem still exists of course.

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I cannot believe this. I found these words of widom at http://www.codeguru.com/forum/showth...hreadid=320358

Apparently, it will automatically truncate MEMO fields if your query has a DISTINCT or a GROUP BY in it. 
(You'd think MSDN would warn you about this). All my test queries had a DISTINCT, and a couple had GROUP BY's

Which led me to this article http://www.jdhodges.com/log/1321/
I will have to filter using PHP instead of SQL. That means a complete re-write of my script.
At this point I can only assume this is the correct solution.
The same truncation problem also occurs using mssql DBs but I don't know if the cause is the same.

[Motoma]

I cannot believe this. I found these words of widom at http://www.codeguru.com/forum/showth...hreadid=320358

Apparently, it will automatically truncate MEMO fields if your query has a DISTINCT or a GROUP BY in it. 
(You'd think MSDN would warn you about this). All my test queries had a DISTINCT, and a couple had GROUP BY's

Which led me to this article http://www.jdhodges.com/log/1321/
I will have to filter using PHP instead of SQL. That means a complete re-write of my script.
At this point I can only assume this is the correct solution.
The same truncation problem also occurs using mssql DBs but I don't know if the cause is the same.

All is starting to become apparent now; truncation occurs (and I knew this before, I just didn't think you had led us down this path) on text fields when using DISTINCT and GROUP BY statements because of the overhead of comparing variable length strings as opposed to fixed length strings.

I had just assumed that when you came into the forums and said "ODBC IS TRUNCATING TEXT FIELDS!" you had tested a simple SELECT query to back your statement up ;)

Be careful now, because this truncation will mean that TEXT (MEMO) fields are only distinct on the first 255 characters!

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Sorry Motoma. I wasn't aware of this problem with memo fields.
Thar was careless of me calling them text fields.
Just goes to show that if I had posted my query with the problem you may have spotted the reason earlier.