mysql中避免重复插入相同数据（insert if not exists）

INSERT INTO admins_groups (admin_id,group_id) values (11,22) WHERE NOT EXISTS (SELECT admin_id FROM admins_groups WHERE admin_id=1 and group_id=14);
该操作 是错误的

INSERT INTO groups (admin_id,out_id) select admin_id,group_id from admins_groups WHERE NOT EXISTS (SELECT admin_id FROM admins_groups WHERE admin_id=1 and group_id=222)   LIMIT 1;
如果符合后面的条件 可以插入多条数据,但LIMIT 1 把它限制为一条

INSERT INTO groups (admin_id,out_id) select 1,group_id from admins_groups WHERE NOT EXISTS (SELECT admin_id FROM admins_groups WHERE admin_id=1 and group_id=222)   LIMIT 1;

如果符合后面的条件 插入一条 admin_id = 1 的 数据.