SQL Update语句不起作用，但来自row = fetch_assoc（）的信息将打印在屏幕上

Question

I am looping through the rows of the database with fetch_assoc() and I am selecting two columns of it. I check the values of these two columns of each row. If they are between 2 values then I updated a third row as 1(TRUE) if a statement is true. I am creating two connections because there are two statements, the one that selects the information and the other that updates the column that I want to be updated. When I try to print the information in the screen it seems that the SELECT statement works but when I try to UPDATE the column that I want the UPDATE statement does not update the database. Here is my code:

$conn= mysqli_connect("localhost","root","root");        

$variablech = 1 ;   

$query = "SELECT Client, Info FROM DataTable";


if ($result = mysqli_query($conn, $query)) {

while($row=mysqli_fetch_row($result)) {

    if((($row['Client']>=54.055) && ($row['Client']<=54.117) ) && (( $row['Info']>=-4.827) && ( $row['Info']<=-4.317)))
   {
    $variablech = 0;

    $sql=  " UPDATE DataTable SET InfoData='$variablech' WHERE Client='".$row['Client']."' AND Info='".$row['Info']."'";
    $conn->query($sql);
    echo "yes";
  }

  else
  {
    $variablech = 1;
    $sql=  " UPDATE DataTable SET InfoData='$variablech' WHERE Client='".$row['Client']."' AND Info'".$row['Info']."'";
    $conn->query($sql);

   echo "no";


  }
}
}

Answer 1

This should do the trick:

...
$sql=  "UPDATE DataTable SET InfoData='".$variablech."' WHERE Client='".$row['Client']."' AND Info='".$row['Info']."'";
mysqli_query($conn, $sql)
...

Suggestion:

Not sure, if you have an auto_increment field in your table. If you do, then select it in select query and then use the same to update the data in update query. That will speed up the database stuff and so is your project.