Reprinted from https://chuanke.baidu.com/v4509752-209102-1284621.html C language C ++ Study Guide (Database articles) MySQL and SQLite
AfMysql.h
. 1 #ifndef _AF_MYSQL_H 2 #define _AF_MYSQL_H . 3 . 4 / * AfMysql . 5 for rotation MySQL field values to the corresponding type . 6 . 7 . 8 Version: 2015-12-20 . 9 official website: http://afanihao.cn C / C ++ Learning Guide (MySQL articles) 10 * / . 11 12 is #include <stdio.h> 13 is #include <stdlib.h> 14 #include < String .h> 15 16 #include < String > . 17 the using STD :: String ; 18 is . 19 class AfMysql 20 { 21 public: 22 // 日期时间类型 23 struct Date 24 { 25 Date():year(2000),month(1), day(1){} 26 int year,month,day; 27 }; 28 struct Time 29 { 30 Time():hour(0),minute(0), second(0){} 31 int hour,minute,second; 32 }; 33 struct DateTime 34 { 35 DateTime(): year(2000), month(1), day(1), hour(0), minute(0), second(0) {} 36 int year,month,day; 37 int hour,minute,second; 38 }; 39 40 // 字符串类型 41 typedef string String; 42 typedef int Int; 43 typedef long long BigInt; 44 45 public: 46 static Int AsInt(const char* field, int length) 47 { 48 if(field==NULL) return 0; 49 return atoi(field); 50 } 51 52 static BigInt AsBigInt(const char* field, int length) 53 { 54 if(field==NULL) return 0; 55 56 long long val; 57 #ifdef _WIN32 58 sscanf(field, "%I64d", &val); 59 #else 60 #endif 61 return val; 62 } 63 64 // 时间类型 65 static Date AsDate(const char* field, int length) 66 { 67 Date val; 68 if(field==NULL) return val; 69 70 sscanf(field, "%d-%d-%d", &val.year, &val.month, &val.day); 71 return val; 72 } 73 static Time AsTime(const char* field, int length) 74 { 75 Time val; 76 if(field==NULL) return val; 77 78 sscanf(field, "%d:%d:%d", &val.hour, &val.minute, &val.second); 79 return val; 80 } 81 82 static DateTime AsDateTime(const char* field, int length) 83 { 84 DateTime val; 85 if(field==NULL) return val; 86 87 sscanf(field, "%d-%d-%d %d:%d:%d", 88 &val.year, &val.month, &val.day, 89 &val.hour, &val.minute, &val.second); 90 return val; 91 } 92 93 static String AsString(const char* field, int length) 94 { 95 if(field==NULL) return ""; 96 97 String val = field; 98 return val; 99 } 100 101 }; 102 103 104 105 106 107 #endif
main.cpp
. 1 #include <stdio.h> 2 #include <stdlib.h> . 3 . 4 #include " AfMysql.h " . 5 . 6 // the MySQL the Windows Support ON . 7 #include <winsock2.h> . 8 #include <mysql.h> . 9 #pragma Comment (lib, "for libmysql") 10 . 11 12 is int my_select (* MYSQL Based Conn) 13 is { 14 // the SQL statements that do not end semicolon. Each execution of only one SQL statement. 15 const char * = SQL " the SELECT * Student the FROM " ; 16 int ret = mysql_query(conn, sql); 17 if(ret != 0) 18 { 19 printf("error: %s \n", mysql_error(conn)); 20 return -1; 21 } 22 23 MYSQL_RES * result = mysql_store_result(conn); 24 if(result == NULL) 25 { 26 //printf("error(%d): %s \n", mysql_errno(conn), mysql_error(conn)); 27 } 28 else 29 { 30 // how many rows 31 my_ulonglong num_rows = mysql_num_rows(result); 32 printf("got %d rows: \n", (int)num_rows); 33 34 // number of fields for each row 35 unsigned int num_fields = mysql_num_fields(result); 36 printf("number of fields: %d \n", (int)num_fields); 37 38 // fetch the rows 39 MYSQL_ROW row; 40 while ((row = mysql_fetch_row(result))) 41 { 42 unsigned long *lengths = mysql_fetch_lengths(result); 43 for(int i = 0; i < num_fields; i++) 44 { 45 char* field = row[i]; // can be a NULL value 46 unsigned int field_length = lengths[i]; // the data length 47 48 //printf(" column[%d], length[%d] , data[%s] \n", 49 // i, field_length, field ? field : "null"); 50 // 处理每个字段 51 if(i==0) 52 { 53 AfMysql::Int val = AfMysql::AsInt(field, field_length); 54 printf("id: %d \n", val); 55 } 56 if(i==1) 57 { 58 AfMysql::String val = AfMysql::AsString(field, field_length); 59 printf("name: %s \n", val.c_str()); 60 } 61 if(i==2) 62 { 63 AfMysql::Date val = AfMysql::AsDate(field, field_length); 64 printf("date: %d-%d-%d\n", val.year, val.month, val.day); 65 } 66 if(i==3) 67 { 68 AfMysql::String val = AfMysql::AsString(field, field_length); 69 printf("cellphone: %s \n", val.c_str()); 70 } 71 } 72 printf("\n"); 73 } 74 75 // release the memory 76 mysql_free_result(result) ; 77 } 78 79 return 0; 80 } 81 82 int main() 83 { 84 long long val; 85 sscanf("102388982430234", "%I64d", &val); 86 87 if (mysql_library_init(0, NULL, NULL)) 88 { 89 printf("could not initialize MySQL library\n"); 90 return -1; 91 } 92 93 // 连接服务器 94 MYSQL conn; 95 mysql_init(&conn); 96 97 MYSQL* ret = mysql_real_connect(&conn, 98 "127.0.0.1","root","123456","example" 99 ,0,NULL,0); 100 if (!ret) 101 { 102 printf("Failed to connect to database: %s\n", 103 mysql_error(&conn)); 104 } 105 106 my_select(&conn); 107 108 //Close the connection 109 mysql_close (& Conn); 110 111 mysql_library_end (); 112 return 0 ; 113 }