帮助我在下面哪个代码更好。
有5个$program 1,$program 2,.....在 php/html 文件中。
第一种方法:多和条件,这样好吗?
$sql = "SELECT * FROM test1 WHERE univ_name='$univ_name' AND program='$program1' AND program='$program2' AND program='$program3' AND program='$program4' AND program='$program5'";
$result = mysqli_query($con, $sql);
$resultCheck = mysqli_num_rows($result);
if ($resultCheck < 1) {
//my code goes here
}
第二种方法:我不知道这是否有效并在数据库中插入值。
$sql = "SELECT * FROM test1 WHERE univ_name='$univ_name' AND program='$program1, $program2, $program3, $program4, $program5'";
$result = mysqli_query($con, $sql);
$resultCheck = mysqli_num_rows($result);
if ($resultCheck < 1) {
//my code goes here
}
如果您尝试获取 program 是$program
变量中的值之一的所有行,则可以使用IN
https://dev.mysql.com/doc/refman/8.0/en/comparison-operators.html#function_in
$sql = "SELECT * FROM test1 WHERE
univ_name='$univ_name'
AND program IN (
'$program1',
'$program2',
'$program3',
'$program4',
'$program5'
)";