I'm using Oracle's JDBC thin driver (10.2.0.3) for connecting to an Oracle 10g database. I'd like to get information about the database columns, so I use ResultSetMetaData. The most important information I need is the type of the column and the length, so I use getColumnType, getPrecision, and getScale methods.
It works for a simple query (select * from tablename) if the column type is "simple" like VARCHAR2(50), NUMBER(5), NUMBER(6,2). If I have a more complex query (select count(*) from tablename) or a query based on a view which contains some complex calculation, the methods give weird results like:
getScale: -127getPrecision and getScale is 0getPrecision: -1Setting the oracle.jdbc.J2EE13Compliant connection property to true (as suggested by several webpages) eliminates getScale=-127 but still returns 0/0 result.
Most likely I have to create a workaround for these weird results, but first I need at least a comprehensive documentation about the behavior of Oracle's ResultSetMetaData. For instance a huge table with the meaning of getPrecision/getScale for all the SQL types would be great. Is there a documentation like this somewhere?
Oracle can not return a type based on a view or the count(*) as it was not explicitly declared. Your view could return any precision or scale depending on the underlaying tables of the view.
To overcome this you would need to cast the type in your query or view like this:
select CAST (count(*) AS NUMBER(30))