linux下mysql函数的详细案列

1 MYSQL  *    STDCALL mysql_real_connect(MYSQL *mysql, const char *host,

2                                            const char *user,

3                                            const char *passwd,

4                                            unsigned int port,

5                                            const char *unix_socket,

6                                            unsigned int clientflag);

 

 

 

1.  如何连接数据mysql数据库...。

 

[gxjun@localhost Mysql]$ cat demo.c

                                                                                                                                                                                                

 1 //connect to mysql

 2 #include<stdio.h>

 3 #include"mysql.h"

 4                                                                                                                                                                                                 

 5 int main (void)

 6 {                                                                                                                                                                                               

 7   MYSQL mysql;                  //need a instance to init

 8                                                                                                                                                                                                 

 9   int t, r;                     //connect the database

10                                                                                                                                                                                                 

11   mysql_init (&mysql);

12                                                                                                                                                                                                 

13   if (!mysql_real_connect

14       (&mysql, "localhost", "root", "123", "demo", 0, NULL, 0))

15     {

16       printf ("Error connecting to database:%s\n", mysql_error (&mysql));

17     }

18   else

19     {

20       printf ("Connected MYSQL successfully!\n");

21     }

22   mysql_close (&mysql);

23   return 0;

24 }

25 

26  

 

2.关于make文件的内容：

 

[gxjun@localhost Mysql]$ cat demo.mk

 1 .SUFFIXES: .o .c

 2                                                                                                                                                                                                

 3 CC = gcc

 4 SRC = demo.c

 5 OBJS = $(SRC : .c = .o)

 6 EXEC = demo

 7                                                                                                                                                                                                

 8 .PHONY: start

 9                                                                                                                                                                                                

10 start: $(OBJS)

11 

12         $(CC)   -o $(EXEC) $(OBJS)    -I/usr/include/mysql -L/usr/lib/mysql -lmysqlclient

13 

14 $(OBJS): $(SRC)

15 

16         $(CC)  -g  -Wall $(OBJS) -c $(SRC)  #-I/usr/include/mysql  -L/usr/lib/mysql  -lmysqlclient

17  

18 .PHONY: clean

19 

20 clean:

21          rm -f $(OBJS)

22  

 

/*

几点说明，对于MYSQL数据库程序进行编译，无法像编译普通程序那样，而是要制定include路径，库文件路径和链接模块mysqlclient , 在某些系统上，可能还要用-lz选项链接压缩库。 假设MYSQL的头文件在、usr/include/mysql 路径下 ，库文件在/usr/lib/mysql 路径下，则执行如下命令 

              -I/usr/include/mysql  -L/usr/lib/mysql  -lmysqlclient  

*/

 

3.   进行make编译：     make -f demo.mk

 

二：   数据查询函数

   

[gxjun@localhost demo1]$ cat query.c
//select.c

 1 #include<stdio.h>

 2 #include"mysql.h"

 3 

 4 int main (void)

 5 {

 6 

 7   MYSQL mysql;

 8   MYSQL_RES *res;

 9   MYSQL_ROW row;

10   char *query;

11   int flag, t;                  //connect the database

12 

13   mysql_init (&mysql);

14   if (!mysql_real_connect

15       (&mysql, "localhost", "root", "123", "demo", 0, NULL, 0))

16     {

17       printf ("Failed to connect to Mysql! \n");

18       return 0;

19     }

20   else

21     {

22       printf ("Connected MySQL successfully!\n");

23       query = "select * from student";

24       flag = mysql_real_query (&mysql, query, (unsigned int) strlen (query));

25       if (flag)

26         {

27           printf ("query failed ! \n");

28           return 0;

29         }

30       else

31         {

32           printf ("[ %s ] made...\n", query);

33         }

34       res = mysql_store_result (&mysql);

35       while (row = mysql_fetch_row (res))

36         {

37           for (t = 0; t < mysql_num_fields (res); t++)

38             printf ("%s  ", row[t]);

39           printf ("\n");

40         }

41       mysql_close (&mysql);

42       return 0;

43     }

44 

45   return 0;

46 }

 

 

函数关于Mysql查询语句：

（1） int      STDCALL mysql_query(MYSQL *mysql, const char *q);

（2） int      STDCALL mysql_real_query(MYSQL *mysql, const char *q,  unsigned int length);

 关于这两个函数，使用较多的为（2）式

 

//makefile文件....

 

[gxjun@localhost demo1]$ cat query.mk

 1 .SUFFIXES: .o .c

 2 CC = gcc

 3 SRC = query.c

 4 OBJS = $(SRC: .c = .o)

 5 EXEC = Demo

 6 CLS = rm

 7 

 8 .PHONY: start

 9 

10 start: $(OBJS)

11 

12         $(CC) -o $(EXEC)   $(OBJS) -I/usr/include/mysql -L/usr/lib/mysql -lmysqlclient

13 

14 $(OBJS): $(SRC)

15 

16         $(CC) -g -Wall $(OBJS) -c $(SRC)   -I/usr/include/mysql -L/usr/lib/mysql -lmysqlclient

17 .PHONY: clean

18 clean:

19         $(CLS) -f $(OBJS)

 

 

关于bash 语言：

         [gxjun@localhost demo1]$ cat query.sh

      

    indent -gnu query.c



          echo "make is running ....!"



          make -f query.mk



          echo "make is stopping ....! "

 

使用关于nm 查看想要看的函数 ；

 

  [gxjun@localhost demo1]$ nm Demo

08049aac A __bss_start
080485d0 t call_gmon_start
08049aac b completed.1
08049a64 d __CTOR_END__
08049a60 d __CTOR_LIST__
08049984 D __data_start
08049984 W data_start
08048864 t __do_global_ctors_aux
080485f4 t __do_global_dtors_aux
08049988 D __dso_handle
08049a6c d __DTOR_END__
08049a68 d __DTOR_LIST__
08049990 A _DYNAMIC
08049aac A _edata
08048980 r __EH_FRAME_BEGIN__
08049ab0 A _end
08048888 T _fini
08049984 A __fini_array_end
08049984 A __fini_array_start
080488c0 R _fp_hw
08048630 t frame_dummy
08048980 r __FRAME_END__
08049a74 A _GLOBAL_OFFSET_TABLE_
         w __gmon_start__
080484e4 T _init
08049984 A __init_array_end
08049984 A __init_array_start
080488c4 R _IO_stdin_used
08049a70 d __JCR_END__
08049a70 d __JCR_LIST__
         w _Jv_RegisterClasses
08048830 T __libc_csu_fini
08048800 T __libc_csu_init
         U __libc_start_main@@GLIBC_2.0
0804865c T main
         U mysql_close
         U mysql_fetch_row
         U mysql_init
         U mysql_num_fields
         U mysql_real_connect
         U mysql_real_query
         U mysql_store_result
0804998c d p.0
         U printf@@GLIBC_2.0
080485ac T _start
         U strlen@@GLIBC_2.0

 

 

我们想要查询的表单：

  

mysql> select * from student
    -> ;
+------+-------+
| sno  | sname |
+------+-------+
| 1001 | jim   |
+------+-------+
1 row in set (0.05 sec)

关于MYSQL函数查询结果:

   [gxjun@localhost demo1]$ ./Demo

      Connected MySQL successfully!
      [ select * from student ] made...
       1001  jim

 

---------------------------------------------华丽丽的分割线-----------------------------------------------------

 

关于数据库的插入和查询以及连接的综合案列：

 

 

[gxjun@localhost demo2]$ cat adddata.c

 1 #include<stdio.h>

 2 #include<string.h>

 3 #include<stdlib.h>

 4 #include "mysql.h"

 5 //#include<fcntl.h>

 6 

 7 int

 8 main (void)

 9 {

10 

11   MYSQL mysql;                  //var mysql

12   MYSQL_RES *res;               //grep_result

13   MYSQL_ROW row;                //mysql_row

14   int r;                        //var_tmp  r

15   char *query[4];

16   int flag;

17   //init_mysql

18   mysql_init (&mysql);

19   if (!mysql_real_connect

20       (&mysql, "localhost", "root", "123", "demo", 0, NULL, 0))

21     {

22 

23       printf ("can't connect the mysql ! errInfo=[%s]", mysql_error (&mysql));

24 

25     }

26   else

27     {

28       printf ("connect the mysql successfully!");

29       query[0] = "insert into student(sno,sname)values(1002,'tom')";

30       query[1] = "insert into student(sno,sname)values(1003,'gongxijun')";

31       query[2] = "insert into student(sno,sname)values(1004,'qinshihuang')";

32 //insert data to mysql

33       for (r = 0; r < 3; r++)

34         {

35           if (mysql_real_query

36               (&mysql, query[r], (unsigned int) strlen (query[r])))

37             {

38               printf ("insert data[%d] is failed !\n", r);

39               return 0;

40             }

41           else

42             {

43               printf ("Insert data[%d] is successfully !\n", r);

44             }

45         }

46     }

47 

48 //query part

49   query[3] = "select * from student";

50   flag =

51     mysql_real_query (&mysql, query[3], (unsigned int) strlen (query[3]));

52   if (!flag)

53     {

54       res = mysql_store_result (&mysql);

55       while (row = mysql_fetch_row (res))

56         {

57           for (r = 0; r < mysql_num_fields (res); r++)

58             {

59               printf ("%s ", row[r]);

60             }

61           printf ("\n");

62         }

63     }

64   else

65     {

66       printf ("query failed !\n");

67       return 0;

68 

69     }

70   mysql_close (&mysql);

71   return 0;

72 }

73  

 

//关于makefile文件：

 

 [gxjun@localhost demo2]$ cat adddata.mk

 1 .SUFFIXES: .o .c

 2 CC = gcc

 3 SRC = adddata.c

 4 OBJS = $(SRC: .c = .o)

 5 EXEC = Demo

 6 

 7 .PHONY: start

 8 start: $(OBJS)

 9 

10         $(CC) -o $(EXEC) $(OBJS) -I/usr/include/mysql -L/usr/lib/mysql -lmysqlclient

11 

12 $(OBJS): $(SRC)

13 

14         $(CC) -g  -Wall $(OBJS) -c $(SRC)  -I/usr/include/mysql -L/usr/lib/mysql -lmysqlcilent

15 

16 .PHONY: clean

17 

18 clean:

19         rm -f $(OBJS) core.*

20 

21  

 

//关于shell文件

  [gxjun@localhost demo2]$ cat adddata.sh

1 #!/bin/bash/

2 

3 echo "make is starting ....!"

4 indent -gnu adddata.c

5 

6 make -f adddata.mk

7 echo "make is endding ...! "

8 

9  

 

显示结果：

[gxjun@localhost demo2]$ ./Demo
connect the mysql successfully!Insert data[0] is successfully !
Insert data[1] is successfully !
Insert data[2] is successfully !
1001 jim
1002 tom
1003 gongxijun
1004 qinshihuang
[gxjun@localhost demo2]$ ls

 

 

 

关于数据库的插入和查询以及连接的综合案列：

 

 

[gxjun@localhost demo2]$ cat adddata.c

 1 #include<stdio.h>

 2 #include<string.h>

 3 #include<stdlib.h>

 4 #include "mysql.h"

 5 //#include<fcntl.h>

 6 

 7 int

 8 main (void)

 9 {

10 

11   MYSQL mysql;                  //var mysql

12   MYSQL_RES *res;               //grep_result

13   MYSQL_ROW row;                //mysql_row

14   int r;                        //var_tmp  r

15   char *query[4];

16   int flag;

17   //init_mysql

18   mysql_init (&mysql);

19   if (!mysql_real_connect

20       (&mysql, "localhost", "root", "123", "demo", 0, NULL, 0))

21     {

22 

23       printf ("can't connect the mysql ! errInfo=[%s]", mysql_error (&mysql));

24 

25     }

26   else

27     {

28       printf ("connect the mysql successfully!");

29       query[0] = "insert into student(sno,sname)values(1002,'tom')";

30       query[1] = "insert into student(sno,sname)values(1003,'gongxijun')";

31       query[2] = "insert into student(sno,sname)values(1004,'qinshihuang')";

32 //insert data to mysql

33       for (r = 0; r < 3; r++)

34         {

35           if (mysql_real_query

36               (&mysql, query[r], (unsigned int) strlen (query[r])))

37             {

38               printf ("insert data[%d] is failed !\n", r);

39               return 0;

40             }

41           else

42             {

43               printf ("Insert data[%d] is successfully !\n", r);

44             }

45         }

46     }

47 

48 //query part

49   query[3] = "select * from student";

50   flag =

51     mysql_real_query (&mysql, query[3], (unsigned int) strlen (query[3]));

52   if (!flag)

53     {

54       res = mysql_store_result (&mysql);

55       while (row = mysql_fetch_row (res))

56         {

57           for (r = 0; r < mysql_num_fields (res); r++)

58             {

59               printf ("%s ", row[r]);

60             }

61           printf ("\n");

62         }

63     }

64   else

65     {

66       printf ("query failed !\n");

67       return 0;

68 

69     }

70   mysql_close (&mysql);

71   return 0;

72 }

73  

 

//关于makefile文件：

 

 [gxjun@localhost demo2]$ cat adddata.mk

 1 .SUFFIXES: .o .c

 2 CC = gcc

 3 SRC = adddata.c

 4 OBJS = $(SRC: .c = .o)

 5 EXEC = Demo

 6 

 7 .PHONY: start

 8 start: $(OBJS)

 9 

10         $(CC) -o $(EXEC) $(OBJS) -I/usr/include/mysql -L/usr/lib/mysql -lmysqlclient

11 

12 $(OBJS): $(SRC)

13 

14         $(CC) -g  -Wall $(OBJS) -c $(SRC)  -I/usr/include/mysql -L/usr/lib/mysql -lmysqlcilent

15 

16 .PHONY: clean

17 

18 clean:

19         rm -f $(OBJS) core.*

 

 

//关于shell文件

  [gxjun@localhost demo2]$ cat adddata.sh

1 #!/bin/bash/

2 

3 echo "make is starting ....!"

4 indent -gnu adddata.c

5 

6 make -f adddata.mk

7 echo "make is endding ...! "

8  

 

显示结果：

[gxjun@localhost demo2]$ ./Demo
connect the mysql successfully!Insert data[0] is successfully !
Insert data[1] is successfully !
Insert data[2] is successfully !
1001 jim
1002 tom
1003 gongxijun
1004 qinshihuang
[gxjun@localhost demo2]$ ls

-------------------------------------华丽丽的分割线-----------------------------------------------------------

|++++++++++++++++++++++显示删除和查询功能++++++++++++++++++++++++++++++++++++|

 

 

del.c代码：

 

 1 #include<stdio.h>

 2 #include<string.h>

 3 #include "mysql.h"

 4 

 5 int

 6 main (void)

 7 {

 8 

 9   MYSQL mysql;

10 

11   MYSQL_RES *res;

12 

13   MYSQL_ROW row;

14   char *query;

15   int rr, flag;

16   mysql_init (&mysql);          //init mysql

17   MYSQL *pts = mysql_real_connect (&mysql, "localhost", "root", "123", "demo", 0, NULL, 0);     //to connect the mysql

18   if (pts == NULL)

19     {

20       printf ("connect is failed !  [%s ]\n", mysql_error (&mysql));

21       return 0;

22     }

23   printf ("conected successfully ! \n");

24 //the part of function is to query the data of mysql

25 

26   query = "select * from student ";

27 

28   flag = mysql_real_query (&mysql, query, (unsigned int) strlen (query));

29   if (flag)

30     {

31       printf ("query the mysql is failed ! [%s ] \n", mysql_error (&mysql));

32       return 0;

33     }

34 

35   res = mysql_store_result (&mysql);    // return a point of res (var MYSQL_RES *)

36 

37   while (row = mysql_fetch_row (res))

38     {                           //to next row

39 

40       for (rr = 0; rr < mysql_num_fields (res); rr++)

41         printf ("[ %s ] ", row[rr]);

42       puts ("");

43     }

44   //the part of del the data  of mysql

45   query = "delete from student where sname = 'gongxijun'";

46   flag = mysql_real_query (&mysql, query, (unsigned int) strlen (query));

47   if (flag)

48     {

49       printf ("sorry ,delect the data of mysql is failed !\n [%s ] ",

50               mysql_error (&mysql));

51       return 0;

52     }

53   //query again

54   query = "select * from student ";

55   flag = mysql_real_query (&mysql, query, (unsigned int) strlen (query));

56   if (flag)

57     {

58       printf ("query failed ! the result= [%s ] \n", mysql_error (&mysql));

59       return 0;

60     }

61   res = mysql_store_result (&mysql);

62   while (row = mysql_fetch_row (res))

63     {

64       for (rr = 0; rr < mysql_num_fields (res); rr++)

65         printf ("[%s ]\n", row[rr]);

66       printf ("\n");

67     }

68   mysql_close (&mysql);         //close mysql

69   return 0;

70 }

71  

 

关于makefile文件  ：   del.mk

 

 1   .SUFFIXES: .o .c

 2 CC = gcc

 3 SRC = del.c

 4 OBJS = $(SRC: .c =.o)

 5 EXEC = Demo

 6                                                                                                                                                   

 7 .PHONY: start

 8 start: $(OBJS)

 9                                                                                                                                                   

10         $(CC) -o $(EXEC) $(OBJS) -I/usr/include/mysql -L/usr/lib/mysql -lmysqlclient

11                                                                                                                                                   

12 $(OBJS): $(SRC)

13                                                                                                                                                   

14         $(CC) -g -Wall $(OBJS) -c  $(SRC) -I/usr/include/mysql -L/usr/lib/mysql -lmysqlclient

15                                                                                                                                                   

16 .PHONY: clean

17 clean:

18         rm -f $(OBJS) core.*

19                                                                                                                                                   

20 ~

21 ~

 

 

  关于bash文件：

 

indent -gnu del.c

 make -f del.mk
 显示结果：
    [gxjun@localhost demo3]$ bash del.sh
bash: /root/.bashrc: 权限不够
make: Circular del.c <- del.c dependency dropped.
gcc -o Demo del.c -I/usr/include/mysql -L/usr/lib/mysql -lmysqlclient
[gxjun@localhost demo3]$ ./Demo
conected successfully !
[ 1001 ] [ jim ]
[ 1002 ] [ tom ]
[ 1003 ] [ gongxijun ]
[ 1004 ] [ qinshihuang ]
sorry ,delect the data of mysql is failed !
[You have an error in your SQL syntax near '* from student where sname =gongxijun' at line 1 ] [gxjun@localhost demo3]$ vi del.c
[gxjun@localhost demo3]$ bash del.sh
bash: /root/.bashrc: 权限不够
make: Circular del.c <- del.c dependency dropped.
gcc -o Demo del.c -I/usr/include/mysql -L/usr/lib/mysql -lmysqlclient
[gxjun@localhost demo3]$ ./Demo
conected successfully !
[ 1001 ] [ jim ]
[ 1002 ] [ tom ]
[ 1003 ] [ gongxijun ]
[ 1004 ] [ qinshihuang ]
sorry ,delect the data of mysql is failed !
[Unknown column 'gongxijun' in 'where clause' ] [gxjun@localhost demo3]$
[gxjun@localhost demo3]$
[gxjun@localhost demo3]$ vi del.c
[gxjun@localhost demo3]$ bash del.sh
bash: /root/.bashrc: 权限不够
make: Circular del.c <- del.c dependency dropped.
gcc -o Demo del.c -I/usr/include/mysql -L/usr/lib/mysql -lmysqlclient
[gxjun@localhost demo3]$ ./Demo
conected successfully !
[ 1001 ] [ jim ]
[ 1002 ] [ tom ]
[ 1003 ] [ gongxijun ]
[ 1004 ] [ qinshihuang ]
[1001 ]
[jim ]

[1002 ]
[tom ]

[1004 ]
[qinshihuang ]