sql - query on mysql table creation composite primary key from foreign keys of two tables -


मेरे पास निम्न तालिकाओं हैं 

  पुस्तकें (बीकेड varchar (255), bkname varchar ( 255), बंकथ वरचर (255), बीक्यूप वक्रार (255), बीकेएएनएन इंट (10)) सदस्य (मेमिड वर्चार (255), मेम्मन वर्चार (255), मेमड्र वखार (255), मेमन वक्रार (255), मेम्मेल वक्रार ( 255))   
  bkid  और  memid  प्राथमिक कुंजी हैं।  
 अब मैं एक < मजबूत> समग्र प्राथमिक कुंजी (बीकेआईडी और मेमिड)  को टेबल <कोड> पुस्तकें  और  सदस्यों,  से विदेशी कुंजी के रूप में लेते हुए वाक्यविन्यास मुझे कुछ त्रुटियां दे रहा है और मैं हूं नई तालिका बनाने में सक्षम नहीं है सारणी मुद्दा (255), मेमिड varchar (255), इश्युस्टेटस varchar (255), संदर्भ विदेशी कुंजी bkid (किताबें), विदेशी कुंजी memid (सदस्यों) संदर्भ, प्राथमिक कुंजी (बकिड, मेमिड));    
 
 
 आपका टेबल विवरण गलत है I यह काम (पर परीक्षण)  
  टेबल मुद्दा पुस्तिकाएं (बीकेड varchar (255) संदर्भ bkid (पुस्तकें), memid varchar (255) संदर्भ memid (सदस्यों), issuestatus varchar (255), प्राथमिक कुंजी (बकिड, मेमिड));   
 सलाह ... यदि आप कर सकते हैं तो VARCHAR (255) के बजाय पूर्णांक आईडी कॉलम का उपयोग करें ... आपको इसे पछतावा नहीं होगा। और उन कॉलम को नल करें।

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