如何结合这两个凭据查询？

Question

我想将这两个查询放入一个查询中。查询的目的是检查凭证是否与表中的任何一个匹配＆＃34; user_credentials＆＃34;或＆＃34;工人＆＃34;。我怎么能这样做？

  

SELECT user_name FROM user_credentials WHERE user_name =＆＃39; $ user_email＆＃39;   AND password =＆＃39; $ user_password＆＃39;

     

SELECT user_name FROM workers WHERE user_name =＆＃39; $ user_email＆＃39;   AND password =＆＃39; $ user_password＆＃39;

Answer 1

试试这个

SELECT user_name FROM user_credentials WHERE user_name = '$user_email' AND password = '$user_password'

union

SELECT user_name FROM workers WHERE user_name = '$user_email' AND password = '$user_password'

然后检查mysqli_num_rows或mysql_num_rows