Question

the follow function is not working

public function matchingService() {

    $stmt = mysqli_prepare($this->connection, "
    INSERT INTO reusematching.matchedtable(user_idUser, productDetail_idProduct,Status,applyData)
        SELECT  waitinglist_user.user_idUser, 
                waitinglist_product.ProductDetail_idProduct, 
                productstatus,          
                waitinglist_user.waitinglistUser_applydata
                FROM reusematching.waitinglist_user, 
                reusematching.waitinglist_product, 
                productinformation.productdetail, 
                productinformation.productstatus
                where (waitinglistProduct_status = 1 
                and waitinglistUser_status = 1 
                and productCategroy_productCategroyID = waitinglistUser_applyProductType
                and ProductDetail_idProduct = idProduct
                and idStatus = waitinglistProduct_status);

    SET SQL_SAFE_UPDATES=0; 

    DELETE FROM reusematching.waitinglist_user
    WHERE Exists
                    (SELECT matchedtable.idMatchedTable
                        FROM  reusematching.matchedtable 
                        where  matchedtable.user_iduser= waitinglist_user.user_idUser);

    DELETE FROM reusematching.waitinglist_product
    WHERE Exists
                    (SELECT matchedtable.idMatchedTable
                        FROM  reusematching.matchedtable 
                        where  matchedtable.ProductDetail_idProduct
                                = waitinglist_product.ProductDetail_idProduct);

    SET SQL_SAFE_UPDATES=1;

    "); 

    $this->throwExceptionOnError();

    mysqli_stmt_execute($stmt);
    $this->throwExceptionOnError();


    mysqli_stmt_free_result($stmt);
    mysqli_close($this->connection);


    return null;
}

the flex shown

Server error MySQL Error – 1064: You have an error in your SQL syntax;
check the manual that corresponds to your MySQL server version for the
right syntax to use near ‘DELETE FROM reusematching.waitinglist_user
WHERE Exists (SELECT matche’ at line 18

Why I have this error? and how to debug it.

Answer 1

The mysql driver in PHP does not allow multiple queries to be issued in a single query() call. This is true of both the old mysql and newer mysqli functions. This is a security measure to prevent some forms of SQL injection attacks.

You’ll have to split your hideously big query statement into multiple (smaller) individual queries:

a) INSERT ... SELECT
b) SET ...
c) DELETE ..
d) etc...