sql - Unique index in already existing database table -

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मैं SQL Server 2008 में मेरे एक डेटाबेस तालिकाओं पर एक नया अद्वितीय अनुक्रमणिका जोड़ने का प्रयास कर रहा हूं यह एक मौजूदा तालिका और स्तंभ है जहां मैं चाहता हूं कि अद्वितीय अनुक्रमणिका में पहले से कुछ डुप्लिकेट मान हैं।

क्या मैं उस कॉलम के लिए एक अद्वितीय अनुक्रमणिका सेट कर सकता हूँ? यदि ऐसा है, तो कैसे?

यदि कॉलम में पहले से ही डुप्लिकेट मान हैं तो मैं आपको एक अद्वितीय कम्पोजिट बनाने की सलाह देता हूं इसके बजाय कुंजी।

उदाहरण के लिए इसलिए, इस तालिका डिजाइन के साथ उस मुद्दे को संभालने के लिए, आपको ग्राहक ID / ProductID कॉलम पर एक अद्वितीय बाधा बनाने की आवश्यकता है:

ग्राहक उत्पाद (ग्राहक आईडी, उत्पाद आईडी) पर अद्वितीय अनुक्रमणिका cust_products_unique बनाएं

तो संक्षेप में, खेतों के संयोजन सुनिश्चित करते हैं कि सूचकांक अद्वितीय है।

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