Php 如何解析json数组并将其保存到数据库？

我有一个json文件，结构如下：

 [{"id":"PMC4640113",
"Original_paper":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4640113/pdf",
"Title":"Esculin improves dyslipidemia, inflammation and renal damage in streptozotocin-induced diabetic rats",
"Molecules":[{"Main name":"triglyceride", "Synonyms":[]},{"Main name":"acid", "Synonyms":[]},{"Main name":"lipids", "Synonyms":[]},{"Main name":"coumarin", "Synonyms":[]},{"Main name":"coumarins", "Synonyms":[]},{"Main name":"esculetin", "Synonyms":["esculin"]},{"Main name":"fraxetin",         "Synonyms":[]},{"Main name":"triglycerides", "Synonyms":[]},{"Main name":"sugar", "Synonyms":[]}],
"ToxKeywords":"nephrotoxicity, ",
"Important_sentences":["Naaz F, et al. [20] demonstrated that the protective efficacy of esculin against pro-oxidant AFB1-induced nephrotoxicity in mice might be due to its antioxidants and free radical scavenging properties."]
}]

当我

json\u decode（）

时，json会给出以下结果：

 Array ( [0] => Array ( 
[id] => PMC4640113 
[Original_paper] => https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4640113/pdf 
[Title] => Esculin improves dyslipidemia, inflammation and renal damage in streptozotocin-induced diabetic rats 
[Molecules] => Array ( [0] => Array ( [Main name] => triglyceride [Synonyms] => Array ( ) ) [1] => Array ( [Main name] => acid [Synonyms] => Array ( ) ) [2] => Array ( [Main name] => lipids [Synonyms] => Array ( ) ) [3] => Array ( [Main name] => coumarin [Synonyms] => Array ( ) ) [4] => Array ( [Main name] => coumarins [Synonyms] => Array ( ) ) [5] => Array ( [Main name] => esculetin [Synonyms] => Array ( [0] => esculin ) ) [6] => Array ( [Main name] => fraxetin [Synonyms] => Array ( ) ) [7] => Array ( [Main name] => triglycerides [Synonyms] => Array ( ) ) [8] => Array ( [Main name] => sugar [Synonyms] => Array ( ) ) ) 
[ToxKeywords] => nephrotoxicity, 
[Important_sentences] => Array ( [0] => Naaz F, et al. [20] demonstrated that the protective efficacy of esculin against pro-oxidant AFB1-induced nephrotoxicity in mice might be due to its antioxidants and free radical scavenging properties. ) ) ) 

我的困难是当我想保存所有的

[Molecules][Main name]

时，它只保存一个[Main name]。我想将其全部保存为字符串，因此我尝试了以下方法：

 if (is_array($array)) {
    foreach ($array as $item) {
        $jsonTextMining = new JsonTextMining();
        $jsonTextMining->setSolrId($item['id']);
        $jsonTextMining->setOriginalPaper($item['Original_paper']);
        $jsonTextMining->setTitle($item['Title']);
        foreach ($item['Molecules'] as $mol) {
            $jsonTextMining->setMoleculeName(implode($mol['Main name']));
        }
        foreach ($item['Molecules'] as $mol) {
            $jsonTextMining->setSynonymName(implode($mol['Synonyms']));
        }
        $jsonTextMining->setKeyword($item['ToxKeywords']);
        $jsonTextMining->setImportantSentence(implode($item['Important_sentences']));

        $em = $this->getDoctrine()->getManager();
        $em->persist($jsonTextMining);
    }
}

我遇到了一个错误

警告：内爆（）：参数必须是数组
，而它在[同义词]上工作

所以我的问题是：如何将所有
[主要名称]
保存到我的数据库？

我尝试了许多其他的方法，但没有结果，所以我来到这里，希望有人知道如何做到这一点。
致以最良好的祝愿

if (is_array($array)) {
    foreach ($array as $item) {
        $jsonTextMining = new JsonTextMining();
        $jsonTextMining->setSolrId($item['id']);
        $jsonTextMining->setOriginalPaper($item['Original_paper']);
        $jsonTextMining->setTitle($item['Title']);
        $mol_mainname = array();
        foreach ($item['Molecules'] as $mol) {
            array_push($mol_mainname,$mol['Main name']);
        }
        $jsonTextMining->setMoleculeName(implode($mol_mainname));
        foreach ($item['Molecules'] as $mol) {
            $jsonTextMining->setSynonymName(implode($mol['Synonyms']));
        }
        $jsonTextMining->setKeyword($item['ToxKeywords']);
        $jsonTextMining->setImportantSentence(implode($item['Important_sentences']));

        $em = $this->getDoctrine()->getManager();
        $em->persist($jsonTextMining);
    }
}

主名称不是数组，而是字符串。如果要将其内爆，必须首先将其放入数组。
谢谢你的回答，几乎是它，但它给我的名称之间没有空格。有没有办法在它们之间放置空格或字符？
内爆（“，$mol\u mainname）