mysql - Rails 4 joining associated tables - sorting when some records don't have an association -


मैं निम्नलिखित का उपयोग कर रहा हूं: 

  वाहन। Joins (: आपूर्तिकर्ता, मालिक, : मॉडल) .ऑर्डर ("# {sort_column} # {sort_direction}")

जो मुझे 4 संबंधित मॉडलों में से किसी भी विशेषता में परिणाम देने का आदेश देता है। समस्या तब होती है जब एक विशिष्ट वाहन का कोई संघ नहीं होता है, उदाहरण के लिए एक आपूर्तिकर्ता, तो कोई परिणाम नहीं लौटा रहे हैं अगर सभी वाहनों में सभी 3 संगठन हों तो कोई भी परिणाम दिखाएगा।

क्या कोई वैकल्पिक तरीका है जिसकी मुझे ज़रूरत होती है? पोस्ट टेक्स्ट "itemprop =" text ">

डिफ़ॉल्ट रूप से रेल आंतरिक में शामिल होता है यही कारण है कि जब कोई संबंध नहीं होता है तो आपको अभिलेख नहीं दिखाई देता है।

यदि आप चाहते हैं कि आप इसे स्पष्ट रूप से उल्लेख करके इसमें शामिल होने वाले प्रकार को बदल सकते हैं 

  वाहन। "बाएं, वाहनों पर आपूर्तिकर्ताओं को शामिल करें। Supplier_id = suppliers.id") .जोखे ("वाहनों पर वाहनों को शामिल करें। वाहनधारक_आईडी = मालिकों।") .जोखे ("वाहनों पर बाएं जुड़िये मॉडल। मॉडेल_आईडी = मॉडल.आईडी")। ("# {Sort_column} # {sort_direction}")

मैंने एसोसिएशन के नाम के आधार पर आपके टेबल_नाम और विदेशी_की नाम का अनुमान लगाया है। कृपया इसे बदल दें यदि वे अलग-अलग हैं


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