Question

有没有办法在表格中获取SET字段的可用值？

谢谢。

Answer 1

您可以使用DESCRIBE myTableName mySetColumn或SHOW COLUMNS FROM myTableName LIKE mySetColumn检索SET字段的可能值：

  mysql> DESCRIBE myTableName mySetColumn;
  +-------+-------------------------------------------+------+-----+---------+-------+
  | Field | Type                                      | Null | Key | Default | Extra |
  +-------+-------------------------------------------+------+-----+---------+-------+
  | myset | set('Travel','Sports','Dancing','Dining') | YES  |     | NULL    |       |
  +-------+-------------------------------------------+------+-----+---------+-------+

资料性文章here，手册here。

Answer 2

SELECT `COLUMN_TYPE` FROM `information_schema`.`COLUMNS`
 WHERE `TABLE_SCHEMA` = 'my_database_name'
   AND `TABLE_NAME`   = 'my_table_name'
   AND `COLUMN_NAME`  = 'my_set_column';

仅为您提供类型，例如

set('Travel','Sports','Dancing','Dining')

你仍然需要在文本基础上提取设定值，但这样的方法就不那么杂乱了。

Answer 3

从@Andy链接到文档的完整实现：

/**
 * @return array
 * @param table DB table
 * @param column Column name
 * @desc Return an array of the possible values for a SET
 */
function get_set($table,$column)
{
    $sql = "SHOW COLUMNS FROM $table LIKE '$column'";
    if (!($ret = mysql_query($sql)))
        die("Error: Could not show columns");

    $line = mysql_fetch_assoc($ret);
    $set  = $line['Type'];
    // Remove "set(" at start and ");" at end.
    $set  = substr($set,5,strlen($set)-7);
    // Split into an array.
    return preg_split("/','/",$set); 
}

Answer 4

以下是如何使用PDO扩展获取SET的可能值。

function get_set($table, $column)
{

    global $db; //PDO DB Handler

    $sql = "SHOW COLUMNS FROM $table LIKE :column";
    $stmt = $db -> prepare($sql);

    $stmt -> bindParam(":column", $column, PDO::PARAM_STR, 50);

    try {
        $result = $stmt -> execute();
        $row = $stmt -> fetch(PDO::FETCH_ASSOC);
        $set = $row['Type'];
        $set  = substr($set,5,strlen($set)-7);
        // Split into an array.
        return preg_split("/','/",$set);
    } catch (PDOException $e) {
        echo $e -> getMessage();
        return false;
    }

}

[Source]

Answer 5

上述方法对我来说并不完全正常，但我最终得到了这个并且效果很好。发布以防万一在相同情况下帮助其他人。您只需根据结果修剪字符串，因为它会将您的列名称与“set”一词包括在一起。

    <?php>
    include ('database.php');
    $query = "SHOW COLUMNS FROM Products LIKE 'Genre'";

    $stmt = $con->prepare( $query );

    $result = $stmt -> execute();
    if ($result) {
    $row = $stmt -> fetch(PDO::FETCH_ASSOC);
        $genres = implode($row);

        $genres  = substr($genres,10,strlen($genres)-14);
        //echo $genres;
        $genres = preg_split("/','/",$genres);

    //this is to populate my select box options with set values
        echo "<select name = 'genre'>";
        echo "<option>Select...</option>";
        foreach ($genres as $key=>$value) {
            echo "<option name = '$value' value = '$value'>$value</option>";
        };
        echo "</select>";
    }


    ?>

如何获取SET字段的可用值？

5 个答案: