oracle 生成批量授权sql

生成给查询用户VIEWDB赋予生产用户GSCRM_ETL2下所有的表的查询权限的执行语句：

SELECT 'grant select on' || B.TABLE_NAME || ' to VIEWDB;'

from USER_TABLES B

LEFT JOIN user_tab_privs A

ON a.GRANTEE = 'VIEWDB'

AND A.privilege = 'SELECT'

AND B.TABLE_NAME = A.TABLE_NAME

AND A.OWNER = 'GSCRM_ETL2'

WHERE A.GRANTEE IS NULL;