从类型定义结构数组中获取行

Fetching rows in a typedef struct array

本文关键字：获取 数组 结构 类型 定义      更新时间：2023-10-16

我的结构定义如下:

typedef struct{
   int v1;
   int v2;
}INFOS_HND;
INFOS_HND hnd_list[100];
EXEC SQL BEGIN DECLARE SECTION;
   char statement[200];
   int current_row = 0;
EXEC SQL END DECLARE SECTION;

我在pro C/c++中使用这个语句。

snprintf(statement, sizeof(statement), "select i1, i2, from table_a");
这是我的SQL指令: 
EXEC SQL PREPARE SEL_INSTR FROM :statement;
EXEC SQL DECLARE MY_CURSOR CURSOR FOR SEL_INSTR;
EXEC SQL OPEN MY_CURSOR;
EXEC SQL WHENEVER NOT FOUND DO break;
while(1){
   EXEC SQL FETCH MY_CURSOR INTO :hnd_list[current_row].v1, :hnd_list[current_row].v2;
   current_row++;
EXEC SQL CLOSE MY_CURSOR;

编译时，显示以下错误:

PCC-S-02322, found undefined identifier
Semantic error at line 53, column 10, file my_file:
EXEC SQL FETCH MY_CURSOR INTO :hnd_list[current_row].v1;
PCC-S-02327, struct or struct pointer required
Semantic error at line 53, column 10, file my_file:
EXEC SQL FETCH MY_CURSOR INTO :hnd_list[current_row].v1;
PCC-S-02322, found undefined identifier
Semantic error at line 53, column 30, file my_file:
EXEC SQL FETCH MY_CURSOR INTO :hnd_list[current_row].v2;
PCC-S-02327, struct or struct pointer required
Semantic error at line 53, column 30, file my_file:
EXEC SQL FETCH MY_CURSOR INTO :hnd_list[current_row].v2;

类型和变量定义在PRO*C/c++ DECLARE块外声明。所以预编译器不能解析声明。尝试将它们移动到块内，如下所示:

EXEC SQL BEGIN DECLARE SECTION;
typedef struct{
   int v1;
   int v2;
}INFOS_HND;
INFOS_HND hnd_list[100];
char statement[200];
int current_row = 0;
EXEC SQL END DECLARE SECTION;
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