最近编译一个MYSQL例子程序时,编译时出现一些奇怪的错误:
#include <stdio.h>
#include <string.h>
#include <mysql.h>
int main()
{
MYSQL* conn = NULL;
MYSQL_RES* res;
MYSQL_ROW row;
char* statement;
int t;
conn = mysql_init(conn);
if(conn == NULL)
{
printf("mysql_init() error ");
}
if(!mysql_real_connect(conn, "192.168.82.184", "root", "youngshuai", "test", 0, NULL, 0))
{
printf("connect error ");
return -1;
}
statement = "select * from student";
t = mysql_real_query(conn, statement, (unsigned int)strlen(statement));
res = mysql_store_result(conn);
while(row = mysql_fetch_row(res))
{
for(t = 0; t<mysql_num_fields(res); t++)
{
printf("%s", row[t]);
}
printf(" ");
}
mysql_free_result(res);
mysql_close(conn);
return 0;
}
错误信息:
d:\programming\microsoft visual studio\vc98\include\mysql\mysql_com.h(183) : error C2146: syntax error : missing ';' before identifier 'fd'
d:\programming\microsoft visual studio\vc98\include\mysql\mysql_com.h(183) : error C2501: 'SOCKET' : missing storage-class or type specifiers
d:\programming\microsoft visual studio\vc98\include\mysql\mysql_com.h(183) : error C2501: 'fd' : missing storage-class or type specifiers
d:\programming\microsoft visual studio\vc98\include\mysql\mysql_com.h(347) : error C2065: 'SOCKET' : undeclared identifier
d:\programming\microsoft visual studio\vc98\include\mysql\mysql_com.h(347) : error C2146: syntax error : missing ')' before identifier 's'
d:\programming\microsoft visual studio\vc98\include\mysql\mysql_com.h(348) : error C2059: syntax error : ')'
d:\programming\microsoft visual studio\example\mfc\mysqltest.cpp(203) : warning C4018: '<' : signed/unsigned mismatch
执行 cl.exe 时出错
当然不是所谓的语法错误
mysql_com.h中第183行:my_socket fd;
mysql_com.h未包含任何其他头文件,而是被mysql.h包含
而且my_socket 是在mysql.h中定义的:
#ifndef my_socket_defined
#ifdef __WIN__
#define my_socket SOCKET
#else
typedef int my_socket;
#endif /* __WIN__ */
#endif /* my_socket_defined */
#endif /* _global_h */
也就是说my_socket是在包含它自身所在的头文件的头文件中定义的
问题是不是出在这个地方?这样做是否是合法的做法?