PHP在model层内查询数据库

在model层里的PHP:

class modelData{
public function change($tableName) {
$sqlGetAllCode = sprintf("select DISTINCT code FROM %s", $tableName);
$codeArr = DB::select($sqlGetAllCode);
 
$A_data = [];
 
// 遍历查询得到的代码数组
foreach ($codeArr as $codeObj) {
    $code = $codeObj->code;
 
    // 根据每个代码编号，查询相关数据
    $sqlGetData = sprintf("select cumulative, create_time FROM %s WHERE code='%s'", $tableName, $code);
    $codeData = DB::select($sqlGetData);
 
    $A_data[$code] = [];
 
    // 将查询结果中的cumulative值和create_time值存入A_data数组
    foreach ($codeData as $dataObj) {
        array_push($A_data[$code], $dataObj->cumulative);
        array_push($A_data[$code], $dataObj->create_time);
    }
} 
 dd($A_data);
// 返回查询结果 
return $A_data;
    }          
}

查询出的数据

array:4 [▼
  "BX6-01" => array:12 [▼
    0 => "9.4"
    1 => "2018-08-01 08:50:24"
    2 => "8.66"
    3 => "2018-08-02 08:50:24"
    4 => "7.55"
    5 => "2018-08-03 08:50:24"
    6 => "9.35"
    7 => "2018-08-04 08:50:24"
    8 => "10.23"
    9 => "2018-08-05 08:50:24"
    10 => "11.44"
    11 => "2018-08-06 08:50:24"
  ]
  "BX6-02" => array:12 [▼
    0 => "9.4"
    1 => "2018-08-01 08:50:24"
    2 => "8.66"
    3 => "2018-08-02 08:50:24"
    4 => "7.55"
    5 => "2018-08-03 08:50:24"
    6 => "9.35"
    7 => "2018-08-04 08:50:24"
    8 => "10.23"
    9 => "2018-08-05 08:50:24"
    10 => "11.44"
    11 => "2018-08-06 08:50:24"
  ]
  "BX4-01" => array:12 [▼
    0 => "9.4"
    1 => "2018-08-01 08:50:24"
    2 => "8.66"
    3 => "2018-08-02 08:50:24"
    4 => "7.55"
    5 => "2018-08-03 08:50:24"
    6 => "9.35"
    7 => "2018-08-04 08:50:24"
    8 => "10.23"
    9 => "2018-08-05 08:50:24"
    10 => "11.44"
    11 => "2018-08-06 08:50:24"
  ]
  "BX4-02" => array:12 [▼
    0 => "9.4"
    1 => "2018-08-01 08:50:24"
    2 => "8.66"
    3 => "2018-08-02 08:50:24"
    4 => "7.55"
    5 => "2018-08-03 08:50:24"
    6 => "9.35"
    7 => "2018-08-04 08:50:24"
    8 => "10.23"
    9 => "2018-08-05 08:50:24"
    10 => "11.44"
    11 => "2018-08-06 08:50:24"
  ]
]

将查询出的第一cumulative变成数组,再将create_time放进cumulative的数组内,应该怎么在model层内写?

【以下回答由 GPT 生成】

首先，对于这段代码，可以进行以下的优化：

1. 使用预处理语句：为了防止SQL注入攻击，建议使用预处理语句来构建查询语句。可以使用PDO或mysqli扩展库来实现。
2. 使用关联数组存储查询结果：可以使用关联数组来存储查询结果，这样可以直接通过代码编号访问相关数据，提高可读性和操作性。
3. 使用LIMIT限制查询结果数量：如果只需要获取前几条数据，可以加入LIMIT来限制查询结果数量，减少数据库的查询压力。
4. 引入命名空间：通过引入命名空间，可以更好地组织和管理代码。

下面是优化后的代码示例：

namespace App\Model;

use Illuminate\Support\Facades\DB;

class ModelData
{
    public function change($tableName)
    {
        $sqlGetCode = sprintf("SELECT DISTINCT code FROM `%s`;", $tableName);
        $codeArr = DB::select($sqlGetCode);

        $data = [];

        foreach ($codeArr as $codeObj) {
            $code = $codeObj->code;

            $sqlGetData = sprintf("SELECT cumulative, create_time FROM `%s` WHERE code = '%s' LIMIT 10;", $tableName, $code);
            $codeData = DB::select($sqlGetData);

            $data[$code] = [];

            foreach ($codeData as $dataObj) {
                $data[$code][] = $dataObj->cumulative;
                $data[$code][] = $dataObj->create_time;
            }
        }

        return $data;
    }
}

使用该方法的示例：

use App\Model\ModelData;

$tableName = 'your_table_name';

$modelData = new ModelData();
$result = $modelData->change($tableName);

// 处理返回的数组结果
foreach ($result as $code => $data) {
    echo "Code: $code\n";
    foreach ($data as $i => $value) {
        echo "Data " . ($i + 1) . ": $value\n";
    }
    echo "\n";
}

使用该示例中的代码，可以优化查询方法，改进性能和可读性。处理返回的数组结果时，可以根据实际需求进行进一步操作。

foreach ($codeData as $dataObj) {
        $A_data[$code][] = [
              $dataObj->cumulative,
              $dataObj->create_time
        ];
    }