Question

我需要帮助编写PHP函数。我的代码：

function get_config() {
 $db = dbServer::getInstance();
 $mysqli = $db->getConnection(); 
 $sql_query = 'SELECT * FROM server_config';
 $result = $mysqli->query($sql_query);

 if ($result->num_rows > 0) {
 while($row = $result->fetch_assoc()) {
 $serverStatus = $row['server_status']; 
 $serverTitle = $row['server_title'];
 }
 }
 }

现在，如果我想要调用该函数并且只有echo，请说$ serverTitle，我应该怎么做？即：

get_config($serverStatus)?

我是PHP的新手。

Answer 1

只需使用＆＃34; Echo＆＃34;你想要什么回报。如果您只想要一件事，那么您将不得不根据行数来更改查询的方式，并可能为查询添加限制。

with t as (
      select date,
             convert(time, [start time]) as starttime,
             dateadd(minute, duration * 5, convert(time, [start time])) as endtime
      from roster
      where date = '2016-08-08' and [staff] = 'ME'
     )
select date, endtime, next_endtime
from (select t.*,
             lead(endtime) over (partition by staff order by starttime) as next_endtime
      from t
     ) t
where next_endtime is not null
order by starttime asc;

Answer 2

编辑您的函数，使其接受将填充配置值的参数。例如，如果将函数声明更改为：

function get_config(&$serverStatus, &$serverTitle){...}

注意参数旁边的&运算符。这意味着无论您对函数执行的任何操作都将在函数完成后继续存在。所以当你在函数内部时......

 $serverStatus = $row['server_status']; 
 $serverTitle = $row['server_title'];

完成此功能后，这些值将可用。你可以使用这样的值：

//call the function, passing in the variables you want filled
get_config($status, $title);
//now, $status and $title have been filled with the DB values
echo $status;

<强>附录

您在评论中提到您喜欢WordPress调用get_param('paramName')来获取特定参数的方法。以下可能有效：

//you pass an item name (must match a DB column) and function will return
// the item's value
function get_config($item) {
    //static means the next time you call this function,
    //the old value will be remembered. 
    static $row = null;

    //if we fetched the row previously, just get the
    //desired config item. This is a lot more efficient than
    //making a DB query every time the function is called
    if($row) return $row[$item];

    $db = dbServer::getInstance();
    $mysqli = $db->getConnection();
    $sql_query = 'SELECT * FROM server_config';
    $result = $mysqli->query($sql_query);

    //save config data in $row so it will be remembered
    // (because we declared this var as static)
    $row = $result->fetch_assoc();
    return $row[$item];//return the item requested
}

要使用此功能，只需将其传递给您需要的配置项的名称：

$status = get_config('server_status');

或者，如果您只想回应配置

echo get_config('server_title');

PHP函数，只调用一个变量

2 个答案: