mysqli_stmt::fetch

    mysqli_stmt_fetch

    (PHP 5, PHP 7, PHP 8)

    mysqli_stmt::fetch -- mysqli_stmt_fetch — Fetch results from a prepared statement into the bound variables

    Descrizione

    Stile orientato agli oggetti

    public mysqli_stmt::fetch(): ?bool

    Stile procedurale

    mysqli_stmt_fetch(mysqli_stmt $statement): ?bool

    Fetch the result from a prepared statement into the variables bound by mysqli_stmt_bind_result().

    Nota:

    Note that all columns must be bound by the application before calling mysqli_stmt_fetch().

    Nota:

    Data is transferred unbuffered without calling mysqli_stmt_store_result() which can decrease performance (but reduces memory cost).

    Elenco dei parametri

    stmt

    Solo nello stile procedurale: un identificatore di statement restituito da mysqli_stmt_init().

    Valori restituiti

    Valori restituiti
    Value Description
    true Success. Data has been fetched
    false Error occurred
    null No more rows/data exists or data truncation occurred

    Errori/Eccezioni

    If mysqli error reporting is enabled (MYSQLI_REPORT_ERROR) and the requested operation fails, a warning is generated. If, in addition, the mode is set to MYSQLI_REPORT_STRICT, a mysqli_sql_exception is thrown instead.

    Esempi

    Example #1 Stile orientato agli oggetti

    <?php
    $mysqli     = new mysqli("localhost", "my_user", "my_password", "world");

    /* check connection */
    if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
    }

    $query = "SELECT Name, CountryCode FROM City ORDER by ID DESC LIMIT 150,5";

    if (    $stmt = $mysqli->prepare($query)) {

    /* execute statement */
    $stmt->execute();

    /* bind result variables */
    $stmt->bind_result($name, $code);

    /* fetch values */
    while ($stmt->fetch()) {
    printf ("%s (%s)\n", $name, $code);
    }

    /* close statement */
    $stmt->close();
    }

    /* close connection */
    $mysqli->close();
    ?>

    Example #2 Stile procedurale

    <?php
    $link     = mysqli_connect("localhost", "my_user", "my_password", "world");

    /* check connection */
    if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
    }

    $query = "SELECT Name, CountryCode FROM City ORDER by ID DESC LIMIT 150,5";

    if (    $stmt = mysqli_prepare($link, $query)) {

    /* execute statement */
    mysqli_stmt_execute($stmt);

    /* bind result variables */
    mysqli_stmt_bind_result($stmt, $name, $code);

    /* fetch values */
    while (mysqli_stmt_fetch($stmt)) {
    printf ("%s (%s)\n", $name, $code);
    }

    /* close statement */
    mysqli_stmt_close($stmt);
    }

    /* close connection */
    mysqli_close($link);
    ?>

    I precedenti esempi visualizzeranno:

    Rockford (USA)
Tallahassee (USA)
Salinas (USA)
Santa Clarita (USA)
Springfield (USA)

    Vedere anche:

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    ＋add a note

    User Contributed Notes 5 notes

    up
    19
    Bruce Martin
    12 years ago
    I was trying to use a generic select * from table statment and have the results returned in an array. I finally came up with this solution, others have similar solutions, but they where not working for me.
    <?php
    //Snip use normal methods to get to this point
    $stmt->execute();
    $metaResults = $stmt->result_metadata();
    $fields = $metaResults->fetch_fields();
    $statementParams='';
    //build the bind_results statement dynamically so I can get the results in an array
    foreach($fields as $field){
    if(empty(    $statementParams)){
    $statementParams.="\$column['".$field->name."']";
    }else{
    $statementParams.=", \$column['".$field->name."']";
    }
    }
    $statment="\$stmt->bind_result($statementParams);";
    eval(    $statment);
    while(    $stmt->fetch()){
    //Now the data is contained in the assoc array $column. Useful if you need to do a foreach, or
    //if your lazy and didn't want to write out each param to bind.
    }
    // Continue on as usual.
    ?>
    up
    6
    dan dot latter at gmail dot com
    17 years ago
    The following function taken from PHP Cookbook 2, returns an associative array of a row in the resultset, place in while loop to iterate through whole result set.

    <?php
    public function fetchArray () {
    $data = mysqli_stmt_result_metadata($this->stmt);
    $fields = array();
    $out = array();

    $fields[0] = &$this->stmt;
    $count = 1;

    while(    $field = mysqli_fetch_field($data)) {
    $fields[$count] = &$out[$field->name];
    $count++;
    }

    call_user_func_array(mysqli_stmt_bind_result, $fields);
    mysqli_stmt_fetch($this->stmt);
    return (    count($out) == 0) ? false : $out;

    }
    ?>
    up
    1
    piedone at pyrocenter dot hu
    16 years ago
    I tried the mentioned stmt_bind_assoc() function, but somehow, very strangely it doesn't allow the values to be written in an array! In the while loop, the row is fetched correctly, but if I write $array[] = $row;, the array will be filled up with the last element of the dataset... Unfortunately I couldn't find a solution.
    up
    3
    Lyndon
    16 years ago
    This function uses the same idea as the last, but instead binds the fields to a given array.
    <?php
    function stmt_bind_assoc (&$stmt, &$out) {
    $data = mysqli_stmt_result_metadata($stmt);
    $fields = array();
    $out = array();

    $fields[0] = $stmt;
    $count = 1;

    while(    $field = mysqli_fetch_field($data)) {
    $fields[$count] = &$out[$field->name];
    $count++;
    }
    call_user_func_array(mysqli_stmt_bind_result, $fields);
    }

    // example

    $stmt = $mysqli->prepare("SELECT name, userid FROM somewhere");
    $stmt->execute();

    $row = array();
    stmt_bind_assoc($stmt, $row);

    // loop through all result rows
    while ($stmt->fetch()) {
    print_r($row);
    }
    ?>
    up
    2
    andrey at php dot net
    19 years ago
    IMPORTANT note: Be careful when you use this function with big result sets or with BLOB/TEXT columns. When one or more columns are of type (MEDIUM|LONG)(BLOB|TEXT) and ::store_result() was not called mysqli_stmt_fetch() will try to allocate at least 16MB for every such column. It _doesn't_ matter that the longest value in the result set is for example 30 bytes, 16MB will be allocated. Therefore it is not the best idea ot use binding of parameters whenever fetching big data. Why? Because once the data is in the mysql result set stored in memory and then second time in the PHP variable.
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