字符串中的MySQL空格导致问题[重复]

Question

   app.get("/query", (req, res) => {
    con.query(
    `SELECT (${req.query.filter}),
     count("${req.query.filter}") AS count,
     AVG(age) AS averageAge
     from census_learn_sql
     GROUP BY (${req.query.filter})
     LIMIT ${req.query.limit}`,
    (err, result, fields) => {
      err ? err : res.send(result);
    }
  );
});

当req.query.filter是一个没有空格的字符串时，比如'education'······这管用。当我试图找到一个有空格的列名时，比如'this havs空格'，这个查询不起作用。我怎么才能修好这个？

Answer 1

我认为反蜱应该有所帮助：

con.query(
`SELECT (\`${req.query.filter}\`),
 count(\`${req.query.filter}\`) AS count,
 AVG(age) AS averageAge
 from census_learn_sql
 GROUP BY (\`${req.query.filter}\`)
 LIMIT ${req.query.limit}`,
(err, result, fields) => {
  err ? err : res.send(result);
}

）；

另外，您不需要到处都是大括号，但是当您需要调用诸如count之类的聚合函数时：

con.query(
`SELECT \`${req.query.filter}\`,
 count(\`${req.query.filter}\`) AS count,
 AVG(age) AS averageAge
 from census_learn_sql
 GROUP BY \`${req.query.filter}\`
 LIMIT ${req.query.limit}`,
(err, result, fields) => {
  err ? err : res.send(result);
}