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  1. #include <array> 
  2. #include <cmath>
  3. #include <iostream>
  4.  
  5. // #define DATA_COUNT 1000000
  6.  #define DATA_COUNT 10
  7. #define COUNT_AS_NAME 3
  8.  
  9. const char name_list[] = {"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"};
  10. constexpr int name_list_size = (sizeof(name_list)/sizeof(name_list[0])-1);
  11. constexpr int name_size = std::log(DATA_COUNT)/std::log(name_list_size)+2;
  12.  
  13. class Data{
  14.   unsigned int data_count_;
  15.   unsigned int count_as_name_;
  16.   unsigned int name_count_;
  17.  
  18.   std::array<char,name_size> name;
  19.   void set_name(){
  20.     auto it = name.begin();
  21.     unsigned int name_count=name_count_;
  22.     bool is1st=true;
  23.     do{
  24.       if(!is1st) --name_count;
  25.       unsigned int index=name_count % name_list_size;
  26.       *it=name_list[index]; ++it;
  27.       name_count -= index;
  28.       name_count /= name_list_size;
  29.       is1st=false;
  30.     }while(name_count);
  31.     *it='\0';
  32.   }
  33.  public:
  34.   Data() : data_count_(DATA_COUNT),count_as_name_(COUNT_AS_NAME),name_count_(0) {
  35.     set_name();
  36.   }
  37.   const char* const get_name() const {
  38.     return name.cbegin();
  39.   }
  40.   const unsigned int get_count_as_name() const {
  41.     return count_as_name_;
  42.   }
  43.   const bool is_end() const {
  44.     return !data_count_;
  45.   }
  46.   void next() {
  47.     --data_count_;
  48.     --count_as_name_;
  49.     if( !count_as_name_ ) {
  50.       count_as_name_=COUNT_AS_NAME;
  51.       ++name_count_;
  52.       set_name();
  53.     }
  54.   }
  55. };
  56.  
  57. int main(){
  58.   std::cout << "DROP TABLE IF EXISTS xxx;" << std::endl;
  59.   std::cout << "CREATE TABLE xxx ( name text NOT NULL, datetime timestamp without time zone NOT NULL, comment text NOT NULL);" << std::endl;
  60.   std::cout << "ALTER TABLE ONLY xxx ADD CONSTRAINT xxx_pkey PRIMARY KEY (name, datetime);" << std::endl;
  61.  
  62.   for(Data data;!data.is_end();data.next()){
  63.     std::cout << "INSERT INTO xxx(name,datetime,comment) VALUES ('" << data.get_name() << "','2019/01/01'::date+" << data.get_count_as_name() << ",'"<< data.get_name()<< data.get_count_as_name() << "');" << std::endl;
  64.   }
  65.   return 0;
  66. }
  67.  
Success #stdin #stdout 0s 4508KB
comments (?)
stdin 
Standard input is empty
stdout 
DROP TABLE IF EXISTS xxx;
CREATE TABLE xxx ( name text NOT NULL, datetime timestamp without time zone NOT NULL, comment text NOT NULL);
ALTER TABLE ONLY xxx ADD CONSTRAINT xxx_pkey PRIMARY KEY (name, datetime);
INSERT INTO xxx(name,datetime,comment) VALUES ('a','2019/01/01'::date+3,'a3');
INSERT INTO xxx(name,datetime,comment) VALUES ('a','2019/01/01'::date+2,'a2');
INSERT INTO xxx(name,datetime,comment) VALUES ('a','2019/01/01'::date+1,'a1');
INSERT INTO xxx(name,datetime,comment) VALUES ('b','2019/01/01'::date+3,'b3');
INSERT INTO xxx(name,datetime,comment) VALUES ('b','2019/01/01'::date+2,'b2');
INSERT INTO xxx(name,datetime,comment) VALUES ('b','2019/01/01'::date+1,'b1');
INSERT INTO xxx(name,datetime,comment) VALUES ('c','2019/01/01'::date+3,'c3');
INSERT INTO xxx(name,datetime,comment) VALUES ('c','2019/01/01'::date+2,'c2');
INSERT INTO xxx(name,datetime,comment) VALUES ('c','2019/01/01'::date+1,'c1');
INSERT INTO xxx(name,datetime,comment) VALUES ('d','2019/01/01'::date+3,'d3');
https://ideone.com/WTthGi
language:
C++14 (gcc 8.3)
created:
5 years ago
visibility:
public

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