A Script That Lists All Tables and Their Column Names With Data Types

 
SET HEADING OFF
SET LINESIZE 400
SET PAGESIZE 1000
BREAK ON TABLE_NAME SKIP 3
SPOOL C:/TAB_COL_REP.TXT;
SELECT TABLE_NAME, COLUMN_NAME, DECODE(NULLABLE,'N',
'NOT NULL','Y','') NULLABLE,
     DECODE

		DATA_TYPE, 'NUMBER',
		TRIM(DATA_TYPE) || '(' || DATA_PRECISION 
|| DECODE ( DATA_SCALE, '0' ,
'' , ',' || DATA_SCALE )  || ')',
		TRIM(DATA_TYPE) || '(' || DATA_LENGTH || ')' ) 
Type  FROM USER_TAB_COLUMNS
  ORDER BY TABLE_NAME, COLUMN_NAME;
SPOOL OFF;