Mysql中的update语句如何嵌套子查询

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参考技术A update tablename a,(select * from tablename where xx='xxx') b set a.xx='xxx' where a.id=b.id 参考技术B UPDATE ccms_case_allot_count SET org_code = BCTL.brno ,collector_name = INF.tlrnoFROM ccms_case_allot_count COLEFT JOIN sys_tlr_info INF ON CO.collector = inf.tlr_nameLEFT JOIN sys_bctl BCTL ON INF.brcode = BCTL.brcode

如何使用 PHP 和 MySQL 创建 JSON 嵌套子父树(PDO 方法)

【中文标题】如何使用 PHP 和 MySQL 创建 JSON 嵌套子父树(PDO 方法)【英文标题】:How to create JSON nested child parent tree with PHP and MySQL(PDO method) 【发布时间】:2016-01-24 08:42:27 【问题描述】:

我正在尝试使用 PHP 和 MySQL 构建嵌套的父子 JSON 树。 我的目标是从我的 MySQL DB 创建一个 JSON 树,并使用 AngularJS 在前端显示一个树。创建树很重要。 我的数据库结构是:

╔═══════╦═══════════════════╦═════════╗ ║ id ║ 姓名 ║parent_id║ ╠═══════╬═══════════════════╬═════════╣ ║ 1 ║ 家长 ║ 0 ║ ║ 2 ║ 儿童 1 ║ 1 ║ ║ 3 ║ 儿童 2 ║ 1 ║ ║ 4 ║ Grand Child-1 ║ 2 ║ ║ 5 ║ Grand Child-2 ║ 2 ║ ║ 6 ║ Grand Child-3 ║ 3 ║ ║ 7 ║ Grand Child-4 ║ 3 ║ ╚═══════╩═══════════════════╩═════════╝

我需要树看起来像:

父母
    |--儿童-1
    | |--孙子-1
    | |_ 孙子-2
    |--Child-2
    | |--孙子-3
    | |_ Grand Child-4

我做了这样的事情:

function hasChild($id)
    $sql = "SELECT count(*) FROM `myTable` WHERE parent_id=".$id;
    $stmt = $this->db->prepare($sql);
    $stmt->execute($a);
    $row = $stmt->fetchAll(PDO::FETCH_ASSOC);
    return $row[0] > 0 ? true : false;
//function hasChild($id)

// create an index on id
$index = array();
foreach($rows as $i =>$row)

    if (hasChild($i)) 
        $index[$row['id']] = $row;
    


// build the tree
foreach($index as $id => $indexRow)

    if ($id === 1) continue;
    $parent = $indexRow['parent_id'];
    $index[$parent]['children'][] = $indexRow;                    

unset($indexRow);

echo json_encode($index);

但它显然没有给我正确的 json 树 :( 我已经查看了嵌套 json 和数组解决方案,但有些东西对我来说并没有点击,所以我希望有人可以帮助我解决这个问题。我可以使用另一种方式,只要我可以拥有相同/相似的功能。 希望我能够很好地描述这种情况,但如果您需要更多数据,请告诉我。 提前致谢!

【问题讨论】:

【参考方案1】:

$a 未定义。您也没有在查询中使用任何占位符,所以我认为这会失败。

试试:

function hasChild($id)
    $sql = "SELECT count(*) as da_count FROM `myTable` WHERE parent_id = ?";
    $stmt = $this->db->prepare($sql);
    $stmt->execute(array($id));
    $row = $stmt->fetch(PDO::FETCH_ASSOC);
    return $row['da_count'] > 0 ? true : false;
//function hasChild($id)

关于准备好的语句的更长的文章:http://php.net/manual/en/pdo.prepared-statements.php。

【讨论】:

感谢您的回复,但我没有使用准备好的语句,所以我刚刚定义了$a = array();,我根据您的建议更改了我的代码,但它仍然无法正常工作:( 您尝试过我的代码还是尝试使用空数组?您正在使用准备好的语句而不是参数化查询。 对不起,我忘了更新你。是的,您的代码有效,并且由于框架纤薄而出现问题。非常感谢。【参考方案2】:

几天前我也遇到了同样的问题,所以找到了另一种方法来解决这个问题

邮递员提前回复


"Status": 200,
"Data": 
    "MyAssetsList": [
        
            "AssetsId": 15,
            "UserCredentialId": 7,
            "NickName": "jals",
            "EquipmentId": "BO_15",
            "EquipmentTypeId": 4,
            "EquipmentTypeValue": "Backhoe",
            "MakeId": 1,
            "OEMName": "JCB",
            "ModelId": 1,
            "ModelName": "EX1235",
            "YearOfPurchase": 2022,
            "OtherOEMName": "rw",
            "OtherModelName": 0,
            "MetricId": 1,
            "Capacity": "1.000 Kg",
            "EquipmentAge": "2 Months",
            "ProcessCompletionPercentage": 100
        ,
        
            "AssetsId": 14,
            "UserCredentialId": 7,
            "NickName": "jal",
            "EquipmentId": "",
            "EquipmentTypeId": 4,
            "EquipmentTypeValue": "Backhoe",
            "MakeId": 1,
            "OEMName": "JCB",
            "ModelId": 1,
            "ModelName": "EX1235",
            "YearOfPurchase": 2022,
            "OtherOEMName": "rw",
            "OtherModelName": 0,
            "MetricId": 1,
            "Capacity": "1.000 Kg",
            "EquipmentAge": "2 Months",
            "ProcessCompletionPercentage": 33.33
        ,
        
            "AssetsId": 13,
            "UserCredentialId": 7,
            "NickName": "rest",
            "EquipmentId": "",
            "EquipmentTypeId": 4,
            "EquipmentTypeValue": "Backhoe",
            "MakeId": 1,
            "OEMName": "JCB",
            "ModelId": 1,
            "ModelName": "EX1235",
            "YearOfPurchase": 2022,
            "OtherOEMName": "rw",
            "OtherModelName": 0,
            "MetricId": 1,
            "Capacity": "1.000 Kg",
            "EquipmentAge": "2 Months",
            "ProcessCompletionPercentage": 33.33
        ,
        
            "AssetsId": 11,
            "UserCredentialId": 7,
            "NickName": "test",
            "EquipmentId": "",
            "EquipmentTypeId": 1,
            "EquipmentTypeValue": "Excavator",
            "MakeId": 1,
            "OEMName": "JCB",
            "ModelId": 1,
            "ModelName": "EX1235",
            "YearOfPurchase": 2022,
            "OtherOEMName": 1,
            "OtherModelName": 1,
            "MetricId": 1,
            "Capacity": "1.000 Kg",
            "EquipmentAge": "2 Months",
            "ProcessCompletionPercentage": 33.33
        ,
    ]
,
"Message": 
    "SuccessMessage": "My Asset Found Successfully"

邮递员在解决树结构问题后的响应很漂亮


"Status": 200,
"Data": 
    "MyAssets": 
        "AssetsId: 15": 
            "AssetId": 15,
            "EquipmentType": 
                "EquipmentTypeId": 4,
                "EquipmentTypeValue": "Backhoe",
                "EquipmentMake": 
                    "EquipmentMakeId": 1,
                    "EquipmentMakeValue": "JCB"
                ,
                "EquipmentModel": 
                    "EquipmentModelId": 1,
                    "EquipmentModelValue": "EX1235"
                ,
                "EquipmentYearOfPurchase": 2022,
                "EquipmentAge": "2 Months",
                "OtherOEMName": "rw",
                "OtherModelName": "rw",
                "MetricType": 
                    "MetricId": 1,
                    "Capacity": "1.000 Kg"
                ,
                "ProcessCompletionPercentage": 100
            
        ,
        "AssetsId: 14": 
            "AssetId": 14,
            "EquipmentType": 
                "EquipmentTypeId": 4,
                "EquipmentTypeValue": "Backhoe",
                "EquipmentMake": 
                    "EquipmentMakeId": 1,
                    "EquipmentMakeValue": "JCB"
                ,
                "EquipmentModel": 
                    "EquipmentModelId": 1,
                    "EquipmentModelValue": "EX1235"
                ,
                "EquipmentYearOfPurchase": 2022,
                "EquipmentAge": "2 Months",
                "OtherOEMName": "rw",
                "OtherModelName": "rw",
                "MetricType": 
                    "MetricId": 1,
                    "Capacity": "1.000 Kg"
                ,
                "ProcessCompletionPercentage": 33.33
            
        ,
        "AssetsId: 13": 
            "AssetId": 13,
            "EquipmentType": 
                "EquipmentTypeId": 4,
                "EquipmentTypeValue": "Backhoe",
                "EquipmentMake": 
                    "EquipmentMakeId": 1,
                    "EquipmentMakeValue": "JCB"
                ,
                "EquipmentModel": 
                    "EquipmentModelId": 1,
                    "EquipmentModelValue": "EX1235"
                ,
                "EquipmentYearOfPurchase": 2022,
                "EquipmentAge": "2 Months",
                "OtherOEMName": "rw",
                "OtherModelName": "rw",
                "MetricType": 
                    "MetricId": 1,
                    "Capacity": "1.000 Kg"
                ,
                "ProcessCompletionPercentage": 33.33
            
        ,
        "AssetsId: 11": 
            "AssetId": 11,
            "EquipmentType": 
                "EquipmentTypeId": 1,
                "EquipmentTypeValue": "Excavator",
                "EquipmentMake": 
                    "EquipmentMakeId": 1,
                    "EquipmentMakeValue": "JCB"
                ,
                "EquipmentModel": 
                    "EquipmentModelId": 1,
                    "EquipmentModelValue": "EX1235"
                ,
                "EquipmentYearOfPurchase": 2022,
                "EquipmentAge": "2 Months",
                "OtherOEMName": 1,
                "OtherModelName": 1,
                "MetricType": 
                    "MetricId": 1,
                    "Capacity": "1.000 Kg"
                ,
                "ProcessCompletionPercentage": 33.33
            
        ,

    ,
    "AssetImageFileReference": "https://localhost/e9/FileServer/AssetsImage/",
    "AssetDocumentFileReference": "https://localhost/e9/FileServer/AssetsDocument/"
,
"Message": 
    "SuccessMessage": "My Asset Found Successfully"

用 PHP 代码创建类似上面的树结构

        $A = array();
        $Data->MyAssetsList = $ResultModel; // ResultModel Has query result of mysql 
    
    
        foreach($ResultModel as $R)
        
            $A['MyAssets']["AssetsId: ".$R->AssetsId]['AssetId']= $R->AssetsId;
            $A['MyAssets']["AssetsId: ".$R->AssetsId]['EquipmentType']["EquipmentTypeId"]= $R->EquipmentTypeId;
            $A['MyAssets']["AssetsId: ".$R->AssetsId]['EquipmentType']["EquipmentTypeValue"]= $R->EquipmentTypeValue;
            $A['MyAssets']["AssetsId: ".$R->AssetsId]['EquipmentType']["EquipmentMake"]['EquipmentMakeId']= $R->MakeId;
            $A['MyAssets']["AssetsId: ".$R->AssetsId]['EquipmentType']["EquipmentMake"]['EquipmentMakeValue']= $R->OEMName;
            $A['MyAssets']["AssetsId: ".$R->AssetsId]['EquipmentType']["EquipmentModel"]['EquipmentModelId']= $R->ModelId;
            $A['MyAssets']["AssetsId: ".$R->AssetsId]['EquipmentType']["EquipmentModel"]['EquipmentModelValue']= $R->ModelName;
            $A['MyAssets']["AssetsId: ".$R->AssetsId]['EquipmentType']["EquipmentYearOfPurchase"]= $R->YearOfPurchase;
            $A['MyAssets']["AssetsId: ".$R->AssetsId]['EquipmentType']["EquipmentAge"]= $R->EquipmentAge;
            $A['MyAssets']["AssetsId: ".$R->AssetsId]['EquipmentType']["OtherOEMName"]= $R->OtherOEMName;
            $A['MyAssets']["AssetsId: ".$R->AssetsId]['EquipmentType']["OtherModelName"]= $R->OtherOEMName;
            $A['MyAssets']["AssetsId: ".$R->AssetsId]['EquipmentType']["MetricType"]['MetricId']= $R->MetricId;
            $A['MyAssets']["AssetsId: ".$R->AssetsId]['EquipmentType']["MetricType"]['Capacity']= $R->Capacity;
            $A['MyAssets']["AssetsId: ".$R->AssetsId]['EquipmentType']["ProcessCompletionPercentage"]= $R->ProcessCompletionPercentage;
            
            
        

        $A['AssetImageFileReference'] = base_url(PATH_TO_FILESERVER_ASSETSIMAGE);
        $A['AssetDocumentFileReference'] = base_url(PATH_TO_FILESERVER_ASSETSDOCUMENT);

【讨论】:

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