【mnesia type bag】

shijiang1130

1. 5> rd(mgmt,{id,name}).
   
2. mgmt
   
3. 6> mnesia:create_table(mgmt,[{attibutes,record_info(fields,mgmt)},{type,bag}]).
   
4. {aborted,{badarg,mgmt,attibutes}}
   
5. 7> mnesia:create_table(mgmt,[{attributes,record_info(fields,mgmt)},{type,bag}]).
   
6. {atomic,ok}
   
7. 8> A=#mgmt{id="1",name="a"}.
   
8. #mgmt{id = "1",name = "a"}
   
9. 9> mnesia:dirty_write(mgmt,A).
   
10. ok
    
11. 
    
12. 10> mnesia:dirty_write(mgmt,#mgmt{id="2",name="a"}).
    
13. ok
    
14. 
    
15. 13> mnesia:transaction(fun()->mnesia:wread({mgmt,"1"}) end).
    
16. {atomic,[#mgmt{id = "1",name = "a"}]}
    
17. 14> mnesia:transaction(fun()->mnesia:wread({mgmt,1}) end).  
    
18. {atomic,[]}
    
19. 15> mnesia:dirty_write(mgmt,#mgmt{id="2",name="2a"}).      
    
20. ok
    
21. 16> mnesia:transaction(fun()->mnesia:wread({mgmt,"2"}) end).
    
22. {atomic,[#mgmt{id = "2",name = "a"},
    
23.          #mgmt{id = "2",name = "2a"}]}
    
24. 17>

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patagonia2

多谢你。 的详细解答。