i have a problem for a while but suddenly it became a terminal error since i got to do this task 'today'. i already tried everything suggested.
caused by a problem at installing oracle i found a workaround and i connect to database with connectionstring below, which works:
Data Source=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.1.1)(PORT=1521)))(CONNECT_DATA=(SERVICE_NAME=MYDATABASE)));User ID=myusername;Password=mypassword;
and in that database i have a connections table which my datalayer uses to connect to other databases. so here begins the problem. when i try to connect to other databases i get the error: ORA-12154: TNS:could not resolve the connect identifier specified.
long story short: i can not touch that table. tnsping does work, so does toad. but plsql developer and visual studio can not. i mean there should be a problem with listener, sqlora, tnsnames or such specific oracle file and i cant find what.
for VS i'd try putting the tnsnames.ora in the bin folder of the app. For sqlplus i'd check that it is in C:\Orant\