数据库是否存在某字段
SELECT COUNT(*) FROM USER_TAB_COLUMNS WHERE TABLE_NAME = ‘表名‘ AND COLUMN_NAME = ‘字段名‘;
数据库是否存在某张表
select count(*) from user_objects where object_name = ‘表名‘;
注：表名和字段名一定要大写
原文：https://www.cnblogs.com/qiu18359243869/p/10529969.html