Mysql:使用 "OR"匹配哪些字段

Question

我有这个查询:

SELECT * FROM accounts WHERE username = "aaa" OR email = "abc@example.com" OR mobile = "123456789"

我可以像这样找到哪个字段匹配:

var username = req.body.username;
var email = req.body.email;
var mobile = req.body.mobile;

database.query("SELECT * FROM accounts WHERE username = ? OR email = ? OR mobile = ?",[username, email, mobile, (err, result)=>{ 
        if (result.username == username) {...}
        if (result.email == email) {...}
        if (result.mobile == mobile) {...}
    }

但是，我想知道哪个字段在不多次使用 if 的情况下匹配(如果可能)。那么，这种形式只能在 Mysql 中使用吗？

Answer 1

您可以将其放入SELECT列表中。您可以使用 CONCAT_WS() 将列列表合并为逗号分隔的列表。它将省略 NULL 值，因此只会列出匹配的字段。

database.query(`SELECT *, 
    CONCAT_WS(',', 
        IF(username = ?, 'username', NULL), 
        IF(email = ?, 'email', NULL), 
        IF(mobile = ?, 'mobile', NULL)) AS matched_fields 
FROM accounts WHERE username = ? OR email = ? OR mobile = ?`, [username, email, mobile, username, email, mobile], (err, result) => {
  var matched = result.matched_fields.split(',');
  matched.each(field => {
    switch(field) {
    case 'username': ...; break;
    case 'email': ...; break;
    case 'mobile': ...; break;
  });
})