C语言中嵌入式SQL语句

EXEC SQL BEGIN DECLARE SECTION;  /*主变量说明开始*/
 char deptname[64];
 char HSno[64];
 char HSname[64];
 char HSsex[64];
 int  HSage;
 int NEWAGE;
        long SQLCODE;
EXEC SQL END DECLARE SECTION;     /*主变量说明结束*/

EXEC SQL INCLUDE sqlca;               /*定义SQL通信区*/

/*************************************************************************/

int main(void)                           /*C语言主程序开始*/
{
 int  count = 0;
 char  yn;                              /*变量yn代表yes或no*/
 printf("Please choose the department name(CS/MA/IS): ");
 scanf("%s", deptname);                 /*为主变量deptname赋值*/
 EXEC SQL CONNECT TO demin USER
      sa;         /*连接数据库TEST*/
 EXEC SQL DECLARE SX CURSOR FOR   /*定义游标*/
  SELECT Sno, Sname, Ssex, Sage   /*SX对应语句的执行结果*/
  FROM Student
  WHERE SDept = :deptname;
 EXEC SQL OPEN SX;        /*打开游标SX便指向查询结果的第一行*/

for ( ; ; )                       /*用循环结构逐条处理结果集中的记录*/
{
 EXEC SQL FETCH SX INTO :HSno, :HSname, :HSsex,:HSage;
      /*推进游标，将当前数据放入主变量*/
if (sqlca->sqlcode != 0)     /* sqlcode != 0,表示操作不成功*/
  break;                /*利用SQLCA中的状态信息决定何时退出循环*/
 if(count++ == 0)             /*如果是第一行的话，先打出行头*/
  printf("\n%-10s %-20s %-10s %-10s\n", "Sno", "Sname", "Ssex", "Sage");
 printf("%-10s %-20s %-10s %-10d\n", HSno, HSname, HSsex, HSage); 
     /*打印查询结果*/
 printf("UPDATE AGE(y/n)?"); /*询问用户是否要更新该学生的年龄*/
 do{                    
    scanf("%c",&yn);
 }
 while(yn != 'N' && yn != 'n' && yn != 'Y' && yn != 'y');
if (yn == 'y' || yn == 'Y')                 /*如果选择更新操作*/
  {
   printf("INPUT NEW AGE:");
   scanf("%d",&NEWAGE);          /*用户输入新年龄到主变量中*/
   EXEC SQL UPDATE Student            /*嵌入式SQL*/
   SET Sage = :NEWAGE
   WHERE CURRENT OF SX ;
  }                 /*对当前游标指向的学生年龄进行更新*/
}

     EXEC SQL CLOSE SX;           /*关闭游标SX不再和查询结果对应*/
 EXEC SQL COMMIT WORK;                           /*提交更新*/
 EXEC SQL DISCONNECT TEST;                  /*断开数据库连接*/
}