如何在mysql查询上写一个php变量

Question

我需要正确编写我的php变量。

$query2 = mysqli_query($con,"SELECT * FROM palettes LIMIT '$starting_number, $palettes_per_page'");

Answer 1

I don't think you want single quotes on your LIMIT parameters. One way is to use . to concatenate strings.

Since $starting_number and $palettes_per_page are integers, you do not need to escape them. If they were strings, wrap them in mysqli_real_escape_string or mysqli_escape_string to escape special characters.

$query2 = mysqli_query( $con,
             "SELECT * FROM palettes LIMIT " .
             $starting_number .
             "," .
             $palettes_per_page );

Answer 2

Just remove the single quote, because double quote can read variable's value

$query2 = mysqli_query($con,"SELECT * FROM palettes LIMIT $starting_number, $palettes_per_page");

Hope this works for you

Answer 3

您可以使用参数化查询，也可以避免使用mysqli_real_escape_string

$stmt = $conn->prepare("SELECT * FROM palettes LIMIT ?, ?'"); $stmt->bind_param("ii", $starting_number, $palettes_per_page); $stmt->execute();