php从基于连接值的变量返回“纯文本字符串”,供sql数据库使用

hello guys i need help returning the "plain string text" from this concatenated value variable that is comprised of other multiple variables with string values.

there is a snippet of the code below and how im trying to get it to work. i am doing it this way for the variable $sql because the search feature on project im working on needs to be dynamic and i have procedural lines of code in place to dynamically edit each of the variables to the right of the $sql variable. i know they work because i can echo the $sql variable and it changes inthe correct fashion

but the problem is if i try to pass the $sql variable to the mysqli_query($conn, $sql) the way i have it in first form wont work.

$sql = $qrySELECT_FROM.$qryWHERE.$Code.$qryAND.$Cardtype.$qryAND.$Issuer.$qryAND.$State.$qryEND;

i need $sql to be returned in plain text string form like the one below to be used as my sql statement for the database in the mysqli_query() function.

$sqlwayineed = "SELECT * FROM Stuff WHERE code =""; AND cardtype ="" AND issuer ="" AND state ="";

can anyone show me the way?

here is fullblown code example to show what im doing and my procedurals https://eval.in/663376