为了提供API接口，我们常常在读取数据库后，将数据转换为数组，通过json_encode转为JSON，即可满足使用需要。现将代码粘帖如下：
- 1.读取一条记录，转为数组并输出JSON
include("../../db/conn.php");//数据库连接； echo "<pre>"; //数据库读取后，直接转换为数组显示; $sql = "select salesid,fromstore,fromsaler,salestime,salenum,totalprice from midea_sales WHERE salesid=44"; $results = mysqli_query($con, $sql); $rows = mysqli_fetch_assoc($results); foreach ($rows as $key => $v) { $res[$key] = $v; } echo json_encode($res);
- 2.读取N条记录，转为多维数组并输出JSON（第一种写法）
//数据库读取后，直接转换为数组显示; $sql = "select salesid,fromstore,fromsaler,salestime,salenum,totalprice from midea_sales"; $results = mysqli_query($con, $sql); $data = array();//初始化数组; class Alteration { public $fromstore; public $fromsaler; public $salenum; public $totalprice; } while ($row = mysqli_fetch_assoc($results)) { $alter = new Alteration();//实例化对象; $alter->fromstore = $row['fromstore']; $alter->fromsaler = $row['fromsaler']; $alter->salenum = $row['salenum']; $alter->totalprice = $row['totalprice']; $data[] = $alter; } echo json_encode($data);
- 3.读取N条记录，转为多维数组并输出JSON（第二种写法）
$sql = "select salesid,fromstore,fromsaler,salestime,salenum,totalprice from midea_sales"; $results = mysqli_query($con, $sql); while ($rows = mysqli_fetch_assoc($results)) { $res[] = $rows; } //$res = str_replace('[', '{', json_encode($res)); //$res = str_replace(']', '}', $res); print_r($res);
4.读取N条记录，转为多维数组并输出JSON（第三种写法），适合获取全部记录
$sql = "select salesid,fromstore,fromsaler,salestime,salenum,totalprice from midea_sales"; $results = mysqli_query($con, $sql); $rows = mysqli_fetch_all($results); print_r($rows);
在转换的过程中，JSON格式会出现[]和｛｝两种格式的JSON，而实际应用中对{}的接口是标准接口。如何转换呢？
原因在于：当array是一个从0开始的连续数组时，json_encode出来的结果是一个由[]括起来的字符串；而当array是不从0开始或者不连续的数组时，json_encode出来的结果是一个由{}括起来的key-value模式的字符串。
$sql = "select salesid,fromstore,fromsaler,salestime,salenum,totalprice from midea_sales"; $results = mysqli_query($con, $sql); $rows = mysqli_fetch_all($results); $rows = str_replace('[', '{', json_encode($rows)); $rows = str_replace(']', '}', $rows); echo json_encode($rows);
lockdatav done!
