Informix ESQL/C使用游标的一个example

#include <stdio.h> 
#include <sqlca.h> 
#include <sqlda.h> 
#include <sqltypes.h> 
#include <sqlstype.h>
#define SUCCESS 0
main() 
{ 
    EXEC SQL INCLUDE SQLCA;                 //包含sqlca
 
    EXEC SQL BEGIN DECLARE SECTION;         //定义主变量
    char *string1;
    char str1[10];
    char str2[10];
    char str3[10];
    EXEC SQL END DECLARE SECTION; 
    

    EXEC SQL CREATE DATABASE example3;     //创建数据库
    EXEC SQL DATABASE example3;            //选择数据库 

    if (SQLCODE == SUCCESS) 
    { 
        EXEC SQL CREATE TABLE Student 
        ( alarm char(6) , 
          sname char(10),
          sex char(10)
        );  
    }
    
    EXEC SQL INSERT INTO Student VALUES("aaaa","bbbb","1"); //向数据库中插入数据 
    EXEC SQL INSERT INTO Student VALUES("dddd","dddd","2"); 
    EXEC SQL INSERT INTO Student VALUES("cccc","cccc","3"); 
    
    EXEC SQL                                       //设置游标其中DECLARE是将查询得结果赋予fet_cur
    DECLARE fet_cur CURSOR FOR
    SELECT alarm, sname,sex FROM Student;
    EXEC SQL OPEN fet_cur;                         
 
    printf("SQLCODE=%d\n", SQLCODE);

 for(;;)
 {
    memset(str1, 0, sizeof(str1));
    memset(str2, 0, sizeof(str2));
    memset(str3, 0, sizeof(str3));
    EXEC SQL FETCH fet_cur INTO :str1,:str2,:str3;  /*把记录游标fet_cir移到一个新位置，凭且把记录值赋予变量str1和str2*/
    if (SQLCODE != SUCCESS)
    {
      printf("LINE=%d, SQLCODE=%d", __LINE__, SQLCODE);
      break;
    }
     printf("str1=%s, str2=%s,str2=%s\n",str1,str2,str3);  
 }
    EXEC SQL CLOSE fet_cur;
    EXEC SQL CLOSE DATABASE;
    return(0); 
}