problem in odbc oracle connector load

[user-azadi]

hello experts,

i am using qlikview 12 and for connect to our oracle database , i install odbc oracle . 

i connect to table of our oracle database and i can see columns same below picture:

but when i go to Preview tab for display fields values , no value display. same below picture:

and when i reload data, display below message:

My question is:

why i can connect to oracle table and view details of fields , but i can't view values of fields in Preview tab. and why display error 942 after reload?

thank you for your attention.

[user-azadi]

Have any answers?