C语言实现myql中存取二进制文件

最近搞mysql，这两天想用C把二进制文件（<64k，大的就存储路径了）存储到数据库里，经过我‘不懈’的搜索，发现NET上有且只有一个版本（php为例的），在C里根本行不通，我先是晕倒，醒了后我再搜索，还是php版本的，我又吐了一口血（之后又吐了好几次）！最后还是在mysql手册里找到了方向，是mysql_real_escape_string给了我光明，好了，不罗嗦了，不然要有矿泉水瓶砸过来了！为了不让其它初学者吐血，我把我的code共享一下，希望大侠们指正，也欢迎鸡蛋和西红柿:m01::m01::m01:

#include <stdio.h>

#include <mysql/mysql.h>

#include <stdlib.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#define host                "localhost"	      //mysql server

#define username        "root"

#define password        "cipher"

#define database         "www"

int get_file_size(char *path, off_t *size)

{

struct stat file_stats;

if(stat(path, &file_stats))

return -1;

*size = file_stats.st_size;

return 0;

}

int main(int argc, char *argv[])

{

char  *filename;

off_t *size;

MYSQL            *conn;

MYSQL_RES    *res_set;

MYSQL_ROW    row;

MYSQL_FIELD *field;

int                    i, flag;

char                *sql;

FILE                *fp;

char                *buf;

int                    n=0;

char                *end;

unsigned long *length;

if (argc != 2) {

printf("Usage: %s srcfile/n", argv[0]);

exit(1);

}

filename = argv[1];

if ((get_file_size(filename, size)) == -1) {

perror("get file size" );

exit(1);

}

if ((buf = (char *)malloc(sizeof(char)*(*size+1))) == NULL) {

perror("malloc buf" );

exit(1);

}

if ((fp = fopen(filename, "rb" )) == NULL) {

perror("fopen file" );

exit(1);

}

if ((n = fread(buf, 1, *size, fp)) < 0) {	//n=*size

perror("fread file" );

exit(1);

}

sql = (char *)malloc(sizeof(char)*n*2+256);	//2n+1+strlen(other sql)

if (sql == NULL) {

perror("malloc sql" );

exit(1);

}

conn = mysql_init(NULL);

if (conn == NULL) {

printf("init mysql, %s/n", mysql_error(conn));

exit(1);

}

if ((mysql_real_connect(conn, host, username, password, database, 0, NULL, 0)) == NULL) {

printf("connect mysql, %s/n", mysql_error(conn));

exit(1);

}

strcpy(sql, "insert into www(id, name, file) values(5, 'peter', " );

end = sql;

end += strlen(sql);		//point sql tail

//convert NUL(ASCII 0)、'/n'、'/r'、'/'’、'''、'"'和Control-Z and so on

*end++ = '/'';

end += mysql_real_escape_string(conn, end, buf, n);

*end++ = '/'';

*end++ = ')';

flag = mysql_real_query(conn, sql, (unsigned int)(end-sql));

if (flag != 0) {

printf("insert failed, %s/n", mysql_error(conn));

exit(1);

}

if ((mysql_real_query(conn, "SELECT file FROM www where id=5", 31)) != 0) {

printf("insert failed, %s/n", mysql_error(conn));

exit(1);

}

res_set = mysql_store_result(conn);

fclose(fp);

fp = NULL;

fp = fopen("foo.bk", "wb" );

while ((row = mysql_fetch_row(res_set)) != NULL) {

length = mysql_fetch_lengths(res_set);

for (i=0; i<mysql_num_fields(res_set); i++) {

fwrite(row[0], 1, length[0], fp);

}

}

fclose(fp);

mysql_close(conn);

free(sql);

sql = NULL;

return 0;

}

//gcc -o mysql_binary mysql_binary.c -lmysqlclient

//usage: ./mysql_binary filename

Makefile：

CXX = gcc

LIBS = -lmysqlclient

PRODUCT = mysql_binary

.LIBPATTERNS: lib%.so lib%.a

vpath %   .

vpath %.c src

vpath %.h include

OBJS = mysql_binary.o

$(PRODUCT): $(OBJS)

$(CXX) $(OBJS) -o $@ $(LIBS)

.c.o:

.PHONY:clean

clean:

-rm -f $(OBJS) $(PRODUCT)