row_count* keywords doesn't work

[poliarush]

i'm using DatabaseLibrary to connect to oracle thru cx_Oracle

${results} Row Count select * from dual
Row Count Is Equal To X select * from dual 1

and it's always returning 0 records

i've fixed query.py and added cur.fetchall() and it's working

    cur = None
    try:
        cur = self._dbconnection.cursor()
        self.__execute_sql(cur, selectStatement)
        cur.fetchall()
        rowCount = cur.rowcount
        return rowCount
    finally :
        if cur :
            self._dbconnection.rollback() 

[zmlpjuran]

This fix is correct. From documentation:

As required by the Python DB API Spec, the rowcount attribute
“is -1 in case no executeXX() has been performed on the cursor or the rowcount of the last operation is not determinable by the interface”.
This includes SELECT statements because we cannot determine the number of rows a query produced until all rows were fetched.

You can also return size of results and don't stick with rowcount attribute:

results = cur.fetchall()
return len(results)

However, it can be very expensive for data transfer between server and client.
I prefer something like:

self.__execute_sql(cur, "select count(1) from (%)" % (selectStatement))
result = cur.fetchone()
rowCount = result[0]
return rowCount

What is your opinion?

[franz-see]

I prefer select count(1) as well. But I think doing a fetchall() prior to rowcount should be enough.

[zmlpjuran]

Forgot to enclose sub-query in brackets, previous comment edited.

[zmlpjuran]

No problem with fetch_all() fix. In case of required performance optimization it can be done the other way.

[jerry57]

I believe this is now fixed for Oracle and SQLite. Please retest on Oracle as I don't have access to a setup right now.

[jerry57]

This should now be resolved with the 0.7 release