复制代码 代码如下:

#include <stdio.h>

#include <string.h>

#include <stdio.h>

#include <sqlca.h>

$struct _db_person

{

char name[30+1];

char card[12+1];

int age;

};

char *trim(char *str)

{

char *p, *buffer;

int len;

if( NULL!=str )

{

len = strlen(str);

if( len > 0 )

{

buffer=(char *)malloc(sizeof(char)*(len+1));

if( NULL != buffer )

{

memmove(buffer, str, len);

buffer[len]=0;

p = buffer + len - 1;

while( (p != buffer) && ((*p > 0x00) && (*p <= ' ')) )

*(p--) = 0;

p = buffer;

while( (*p > 0x00) && (*p <= ' ') )

p++;

strcpy(str, p);

free(buffer);

}

}

}

return str;

}

int GetData(struct _db_person *pps)

{

char strage[20];

memset(pps, 0, sizeof(struct _db_person));

printf("enter name<press enter only to exit>: ");

fgets(pps->name,sizeof(pps->name),stdin);

trim(pps->name);

if( strlen(pps->name) == 0 )

return -1;

printf("enter card no<press enter only to exit>: ");

fgets(pps->card,sizeof(pps->card),stdin);

trim(pps->card);

if( strlen(pps->card) == 0 )

return -2;

printf("enter age<press enter only to exit>: ");

fgets(strage,sizeof(strage),stdin);

trim(strage);

if( strlen(strage) == 0 )

return -3;

pps->age = atoi(strage);

return 0;

}

int main(void)

{

$struct _db_person dbps;

$database exec01;

if( SQLCODE != 0 )

{

printf("open demo1 failure,SQLCODE=%dn",SQLCODE);

return -1;

}

while( 1 )

{

if( GetData(&dbps)<0 )

break;

$insert into person(name, card, age) values($dbps.name, $dbps.card, $dbps.age);

printf("insert data result: SQLCODE=%dn",SQLCODE);

$declare vcursor cursor for select name, card, age into $dbps.name, $dbps.card, $dbps.age from person;

printf("declare vcursor result: SQLCODE=%dn",SQLCODE);

$open vcursor;

printf("open vcursor result: SQLCODE=%dn",SQLCODE);

if( 0==SQLCODE )

{

while( 1 )

{

$fetch vcursor;

if( 0==SQLCODE )

{

printf("name=[%s],card=[%s],age=[%d]n",dbps.name,dbps.card,dbps.age);

}

else

{

if( SQLCODE==100 )

printf("fetch end!n");

else

printf("fetch failure!SQLCODE=%dn",SQLCODE);

break;

}

}

}

$close vcursor;

$free vcursor;

}

$disconnect current;

return 0;

}

程序为简单的C中嵌入informix数据库，源文件为.ec文件，编译器为esql，头文件目录：$(INFORMIXDIR)/include，管理工具dbaccess,用法：dbaccess [dbname]，dbschema，用法：dbschema [-t tabname] –d dbname [filename]

1、由预处理程序根据.ec文件生成.c文件

2、由系统指定的编译器将.c文件编译为obj文件

3、由系统连接程序将obj文件和静态库文件连接，生成可执行文件

所以必须为$CC指定合适的编译器，gcc或g++

linux下安装好informix后添加环境变量

LD_LIBRARY_PATH=$INFORMIXDIR/lib:$/INFORMIXDIR/lib/esql:$LD_LIBRARY_PATH;

export LD_LIBRARY_PATH;

编程

包含头文件：EXEC SQL include “dbdef.h”;

预定义变量：EXEC SQL define MAXLEN 64;

定义变量：

EXEC SQL BEGIN DECLARE SECTION;

char Fname[MAXLEN+1];

EXEC SQL END DECLARE SECTION;

打开数据库：

EXEC SQL connect to ‘dbname';

关闭数据库：

EXEC SQL disconnect current;

定义cursor

EXEC SQL declare cursorname cursor for select……

打开cursor

EXEC SQL open cursorname;

读取数据

EXEC SQL fetch cursorname;

判断操作是否成功

SQLCODE==0

判断数据是否已经结束

if( SQLCODE==100);

或者用下面的变成方式：

复制代码 代码如下:

$include “appdef.h”;

$define MAXLEN 64;

$char Fname[MAXLEN+1];

$database dccdb;

$declare cursorname cursor for select……;

$open cursorname;

$fetch cursorname;

$close cursorname;

$free cursorname;

$disconnect current

下面是makefile的编写，一定要链接库函数，不然会出错

复制代码 代码如下:

CC=gcc

exec01: exec01.o

esql -o exec01 -L$(INFORMIXDIR)/lib exec01.o

exec01.o:

esql -c -I$(INFORMIXDIR)/incl/esql exec01.ec

clean:

rm -f exec01 *.o exec01.c exec01