Preventing sqlplus truncation of column names, without individual column formatting

Question

By default sqlplus truncates column names to the length of the underlying data type. Many of the column names in our database are prefixed by the table name, and therefore look

Answer 1

I don't think sqlplus offers the functionality you are requesting. You might be able to automate the formatting, using some sort of scripting language such as Perl or Python. In other words, query the ALL_TAB_COLS view for the schema and table, and then create the script dynamically with a format column attribute. This will only work, of course, if you have permission to query the ALL_TAB_COLS view (or some other equivalent).

This is a quick proof-of-concept I threw together:

#!/usr/bin/python

import sys
import cx_Oracle

response=raw_input("Enter schema.table_name:  ")
(schema, table) = response.split('.')
schema = schema.upper()
table = table.upper()
sqlstr = """select column_name,
                   data_type,
                   data_length
              from all_tab_cols
             where owner      = '%s'
               and table_name = '%s'""" % ( schema, table )

## open a connection to databases...
try:
    oracle = cx_Oracle.Connection( oracleLogin )
    oracle_cursor = oracle.cursor()

except cx_Oracle.DatabaseError, exc:
    print "Cannot connect to Oracle database as", oracleLogin
    print "Oracle Error %d:  %s" % ( exc.args[0].code, exc.args[0].message )
    sys.exit(1)

try:
    oracle_cursor.execute( sqlstr )

    # fetch resultset from cursor
    for column_name, data_type, data_length in oracle_cursor.fetchmany(256):
        data_length = data_length + 0
        if data_length < len(column_name):
            if data_type == "CHAR" or data_type == "VARCHAR2":
                print "column %s format a%d" % ( column_name.upper(), len(column_name) )
            else:
                print "-- Handle %s, %s, %d" % (column_name, data_type, data_length)

except cx_Oracle.DatabaseError, e:
    print "[Oracle Error %d: %s]:  %s" % (e.args[0].code, e.args[0].message, sqlstr)
    sys.exit(1)

try:
    oracle_cursor.close()
    oracle.close()
except cx_Oracle.DatabaseError, exc:
    print "Warning: Oracle Error %d:  %s" % ( exc.args[0].code, exc.args[0].message )

print "select *"
print "from %s.%s" % ( schema, table )