oracle 查询当前库中所有表以及某表字段信息

1 select utc.COLUMN_ID,utc.TABLE_NAME,utc.COLUMN_NAME,utc.DATA_TYPE||utc.DATA_LENGTH,utc.DATA_DEFAULT,utc.NULLABLE from user_tab_columns utc where table_name = upper('t_alert') order by utc.COLUMN_ID;
2 
3 select table_name from user_tables;