php,sql - 如何更改一列中的值并将其插入到另一列中

Question

I wanna get the values from a column column1 and delete all the (spaces , %20, %2520, _ (underscore), - (hyphen) and . (dot)) from it and save the values to the corresponding place in other column2 .
Is this the right way to do it? will this even work?

$conn = new mysqli($servername, $username, $password,$dbname);

$sql= "SELECT column1 FROM table" ;

$result = $conn->query($sql);

if ($result->num_rows > 0) {

while($row = $result->fetch_assoc()) {


    $x= $row["column1"] ;


$find=array(" ","%20","%2520",".","-","_");
$x= str_replace($find,'',$x);


               $sql2 ="INSERT INTO table
             ( column2 )
             VALUES
             ( '$x' )";

              if ($conn->query($sql2) === TRUE) {
               echo "Record Created <br>";

                }

              else {
               echo "Error creating Record: " . $conn->error;
               }

    }
} else {
    echo "0 results";
}
$conn->close();

Answer 1

You need to Update not Insert .

Use REPLACE function to remove the unwanted characters in your column

First run select and check whether everything is fine then run update

SELECT column1,
       Replace(Replace(Replace(Replace(Replace(Replace(column1, ' ', ''), '%2520', ''), '%20', ''), '_', ''), '-', ''), '.', '') AS column2
FROM   yourtable 

UPDATE tablename
SET    column2 = Replace(Replace(Replace(Replace(Replace(Replace(column1, ' ', ''), '%2520', ''), '%20', ''), '_', ''), '-', ''), '.', '') 

Answer 2

First Step

UPDATE table SET column1 = column2

Second Step

UPDATE table SET column2 = REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(column2, ' ', '') , '%20', '') ,'%2520', ''), '.', '') , '-', '') , '_', '')