NULL value found (oracle DB)

[wKollendorf]

What language are you using?

Python

What version are you using?

0.3.1a3

What database are you using?

Oracle

What dataframe are you using?

polars

Can you describe your bug?

When quering a table with a column containing null values and applying an math operation to it, an error is returned by cx.read_sql. When quering without calculation null is returned without any error (expected behaviour). So when doing some calculation with null values, the result also should be null, without throwing an error.

Database setup if the error only happens on specific data or data type

COLUMN_NAME DATA_TYPE NULLABLE DATA_DEFAULT
col1 BINARY_FLOAT yes (null)
col1 BINARY_FLOAT yes (null)

INSERT INTO test ("col1", "col2") VALUES (123, null)
INSERT INTO test ("col1", "col2") VALUES (456, null)

Example query / code

import connectorx as cx

query = 'select col1, round(col2*1000, 2) from test'

df = cx.read_sql( conn, query, return_type='polars') 

What is the error?

NULL value found

[wangxiaoying]

Hi @wKollendorf , thanks for reporting this error. Can you try pip install connectorx==0.3.1a4 to see whether the new version works?

[wKollendorf]

Hi @wangxiaoying, thanks it is working now! By the way, pip only found version 0.3.1a1. I just built it from master (version 0.3.1.a5).

[wangxiaoying]

By the way, pip only found version 0.3.1a1. I just built it from master (version 0.3.1.a5).

I'm not sure whether it is caused by your dependency issue. But it seems working for me locally:
Anyway I will close this issue. Thanks for the response!