mysql - How to delete composite primary key -


मेरे पास टेबल मित्र सूची है I इसे अपनी समग्र प्राथमिक कुंजी ( friend_of_id , Friends_id_is ) और प्राथमिक कुंजी को हटाने के लिए एक नई कम्पोजिट प्राथमिक कुंजी ( friend_of_aid , मित्रों_एड ) बनाना चाहते हैं। 

  ALTER TABLE friends_list DROP प्राथमिक कुंजी   
 लेकिन यह निम्न त्रुटि दिखा रहा है  
  # 1025 - का नाम बदलने में त्रुटि '। \ Xrcwrn_sms \ # sql-14d4_e0' to। \ Xrcwrn_sms \ friends_list '(errno: 150)   
 मैं निम्नलिखित हूँ, लेकिन समग्र प्राथमिक कुंजी के लिए यह काम नहीं कर रहा है मेरा टेबल संरचना चित्र जैसा है उसका अनुसरण करें  
 यहां छवि विवरण दर्ज करें   
 
 
 इस तालिका में विदेशी कुंजी की जाँच करें, उदाहरण के लिए अगली क्वेरी का प्रयोग करें -  
  SELECT * से f_file_free_name_REFERENTIAL_CONSTRAINTS WHERE CONSTRAINT_SCHEMA = 'डीबी नाम' और आर EFERENCED_TABLE_NAME = 'आपकी तालिका';   
 आपको इन सभी विदेशी कुंजी को पुनः बनाने की आवश्यकता है:  
     
  1.  विदेशी कुंजी ड्रॉप करें  
  2.  आरपीएमरी कुंजी को फिर से बनाएं  
  3.  विदेशी कुंजी (एस) बनाएँ

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