Inserting a CLOB using cx_Oracle

Question

I am trying to insert a CLOB using the following code.

cursor = connection.cursor()
cursor.setinputsizes(HERP = cx_Oracle.CLOB)

cursor.execute("INSERT INTO myTable (FOO, BAR) VALUES (:FOO, :BAR)", FOO=val1, BAR=val2)
cursor.execute("INSERT INTO myTable2 (HERP) VALUES (:HERP)", HERP=val3) 
#len(HERP) 39097

When I run the script WITHOUT cursor.setinputsizes(HERP = cx_Oracle.CLOB) it fails on the second query WITH ValueError: string data too large, when I run the script with cursor.setinputsizes(HERP = cx_Oracle.CLOB) it fails on the first query with DatabaseError: ORA-01036: illegal variable name/number. The CLOB I am trying to insert contains a code snippet (i.e. it has a lot of semi colons, commas and parenthesis), "string".decode("ascii") returns u'string', so unicode isn't the problem... right? I don't know if either of these things are problems. The field in the database is a currently a CLOB, however I have tried it with an NCLOB and the behavior did not change.

I have also tried the field as a BLOB and then used .encode("hex") on the value I was inserting, again same behavior.

I have also tried HERP = cursor.var(cx_Oracle.CLOB) instead of cursor.setinputsizes(HERP = cx_Oracle.CLOB), same issues.

I've been going through the discussions on the cx-oracle-users list, but no luck yet.

It works if I use this line cursor.execute("INSERT INTO myTable2 (HERP) VALUES (:HERP)", HERP="".join(set(val3)).encode("hex")), so I don't think it's an issue with the data's content (This is with the BLOB).

How can I use cx_Oracle to insert a CLOB into an Oracle database?

Answer 1

There are a few possible solutions:

1. Upgrade cx_Oracle. I'm not sure which version you're using, but I'm using python 2.7.2 with cx_Oracle 5.1 and I don't get any errors when inserting 150,000 chars into a CLOB column without using setinputsizes at all.
2. Since setinputsizes applies to every subsequent cursor use, just change it between these different cursor.execute statements.

eg:

cursor = connection.cursor()
cursor.setinputsizes(FOO=None, BAR=None)
cursor.execute("INSERT INTO myTable (FOO, BAR) VALUES (:FOO, :BAR)", 
FOO=val1,  BAR=val2)
cursor.setinputsizes(HERP = cx_Oracle.CLOB)
cursor.execute("INSERT INTO myTable2 (HERP) VALUES (:HERP)", HERP=val3)