如果我在语法中使用变量，查询不起作用

Question

这段代码令我头疼。请帮忙。

newdata <- data.frame(`age in years at last birthday`=34,EDUCAT=3,`thousands of dollars per year`=20,`depressed is cesd >= 16`=0,`regular drinker?`=1, check.names = FALSE)

> newdata
  age in years at last birthday EDUCAT thousands of dollars per year depressed is cesd >= 16
1                            34      3                            20                       0
  regular drinker?
1                1

Answer 1

试

$sql = "SELECT * FROM users where user_id = '".$user_id."'";