Getting the Columns Information with a Single Query? Easy

Easy to do:

Select cols.column_id, cols.column_name as Name, nullable,

 data_type as Type,

 decode(data_type, 'CHAR', char_length,

                   'VARCHAR', char_length,

                   'VARCHAR2', char_length,

                   'NCHAR', char_length,

                   'NVARCHAR', char_length,

                   'NVARCHAR2', char_length,

                   null) nchar_length,

  Decode( data_type, 'NUMBER', data_precision + data_scale, data_length ) Length,

  data_precision Precision, data_scale Scale, data_length dlength, data_default 

  ,' ' comments

  ,DATA_TYPE_MOD

  ,cols.CHAR_USED

  ,InitCap(histogram) histogram

  ,num_distinct

FROM

  sys.DBA_TAB_COLUMNS cols

where

 cols.table_name='ALERT_QT'

ORDER BY COLUMN_ID asc

Results:

Output example

COLUMN_ID	1
NAME	Q_NAME
NULLABLE	Y
TYPE	VARCHAR2
NCHAR_LENGTH	30
LENGTH	30
PRECISION
SCALE
DLENGTH	30
DATA_DEFAULT
COMMENTS
DATA_TYPE_MOD
CHAR_USED	B
HISTOGRAM	None
NUM_DISTINCT