google app engine - StringProperty, None vs. Empty String -

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  वर्ग व्यक्ति (db.Model): first_name = db.StringProperty () middle_name = db.StringProperty () last_name = Db.StringProperty () p1 = व्यक्ति (प्रथम_नाम = 'जोन', अंतिम_नाम = 'स्मिथ') p2 = व्यक्ति (प्रथम_नाम = 'जोन', मध्य_नाव = कोई नहीं, अंतिम_नाम = 'स्मिथ') p3 = व्यक्ति (प्रथम_नाम = 'जॉन ', Middle_name =' ', last_name =' smith ')

p1 और p2 मध्य_नाव = कोई भी नहीं है

पी 3 में middle_name = empty स्ट्रिंग

कौन सा काम बेहतर है?

एसक्यूएल में, मैं कॉलम सेट नल डिफॉल्ट के लिए सेट करता हूं ''

वे पूरी तरह से अलग हैं एक (कोई नहीं) एसक्यूएल न्यूल के बराबर है इसका मतलब यह हो सकता है कि उनका कोई मध्य नाम नहीं है या आप इसे नहीं जानते हैं। '' का मतलब है कि उनके पास मध्यम नाम का लंबाई 0 है। यह लगभग कभी मामला नहीं है।


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