sql - Table in Mysql with unique fields -


मेरे पास निम्न फ़ील्ड के साथ MySQL में एक टेबल है: 

  बनाएँ तालिका तालिका_1 (camp_1 बुलियन, वृक्ष varchar (50), नाम varchar (50), सर्व varchar (50), संख्या varchar (50), प्राथमिक कुंजी (camp_1, पेड़, नाम));

तो मेरे पास ऐसा कुछ हो सकता है: 

  चुनें table_1 aa, bb, cc, null, 123dd, ee, ff, null, 512

समस्या यह है कि मुझे जब सब रिक्त है, तो मेरी प्राथमिक कुंजी (या मुझे तीन विशिष्ट मानों की आवश्यकता होगी) की आवश्यकता है: camp_1, tree, name < / Code>

और यदि सभी शून्य नहीं है तो मुझे किसी चीज़ को सम्मिलित करना पड़ सकता है: 

  चुनें table_1 aa, bb, cc, ddd, 123 aa, bb, सीसी, एर्ट, 123 डीडी, ईई, एफएफ, रिक्त, 512

इस तरह से अगर सब नल नहीं है तो मुझे शिविर, पेड़, दो या अधिक बार (एए, बीबी, सीसी 2 बार अलग-अलग मानों के साथ प्रदर्शित होता है, लेकिन यदि सर्व शून्य नहीं है तो मुझे 1 से अधिक मूल्य के साथ शिविर, पेड़, नाम (डीडी, ईई, एफएफ केवल 1 बार) नहीं हो सकता।

एक सूचकांक है, लेकिन यह नहीं मिला क्योंकि मैं अपनी प्राथमिक कुंजी में नल सम्मिलित नहीं कर सकता।

कुछ मेरी मदद कर सकता है?


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