Linux下使用C的API接口登陆和关闭几种常用的数据库
MySQL下
//dbproc.c
/*************************************************************
FileName : dbproc.c
FileFunc : C语言接口访问MySQL
Version : V0.1
Author : Sunrier
Date : 2012-06-14
Descp : Linux下使用C语言访问MySQL函数
*************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <mysql.h>
static MYSQL s_my_connection;
static int s_iDbconnected = 0;//数据库连接标志 连接时为1,断开时为0
int mysql_login(char* pServer,char *pUser,char *pPassword,char *pDataBase)
{
MYSQL *conn_ptr = NULL;
MYSQL_RES *res_ptr = NULL;
MYSQL_ROW sqlrow;
int iRetCode = 1;
unsigned int uiTimeOut = 7;
if( s_iDbconnected )
return 0;
conn_ptr = mysql_init(&s_my_connection);
if( !conn_ptr )
{
fprintf(stderr,"mysql_init failed ! \n");
return EXIT_FAILURE;
}
iRetCode = mysql_options(&s_my_connection,MYSQL_OPT_CONNECT_TIMEOUT,(const char *)&uiTimeOut);
if( iRetCode )
{
fprintf(stderr,"Connection is timeout! \n");
return EXIT_FAILURE;
}
conn_ptr = NULL;
conn_ptr = mysql_real_connect(&s_my_connection,pServer,pUser,pPassword,pDataBase,0,NULL,0);
if( conn_ptr )
{
printf("MySQL Connection success!\n");
s_iDbconnected = 1;
}
else
{
fprintf(stderr,"Connection failed!\n");
if( mysql_errno(&s_my_connection) )
{
fprintf(stderr,"Connection error %d: %s!\n",mysql_errno(&s_my_connection),mysql_error(&s_my_connection));
return EXIT_FAILURE;
}
}
return EXIT_SUCCESS;
}
void mysql_logout( void )
{
if( s_iDbconnected )
mysql_close(&s_my_connection);//关闭连接
s_iDbconnected = 0 ;
}
//demo.c
/*************************************************************
FileName : demo.c
FileFunc : 测试登陆和关闭MySQL数据库
Version : V0.1
Author : Sunrier
Date : 2012-06-14
Descp : Linux下使用C语言访问MySQL函数
*************************************************************/
#include <stdio.h>
int main(int argc,char *argv[])
{
int iRetCode = 0;
char szServer[20] = "localhost";
//char szServer[20] = "192.168.2.8";
char szUser[20] = "Sunrier";
char szPassword[20] = "redhat";
char szDatabase[20] = "test";
iRetCode = mysql_login(szServer,szUser,szPassword,szDatabase);
if( iRetCode )
{
system("service mysqld start");
iRetCode = mysql_login(szServer,szUser,szPassword,szDatabase);
}
printf("iRetCode = %d \n",iRetCode);
mysql_logout();
return 0;
}
//makefile
#makefile all:demo demo:demo.c dbproc.c @gcc -I/usr/include/mysql $? -L/usr/lib/mysql -lmysqlclient -lz -lm -o demo # gcc -I/usr/include/mysql demo.c dbproc.c -L/usr/lib/mysql -lmysqlclient -lz -lm -o demo clean: @ls | grep -v ^makefile$$ | grep -v [.]c$$ | grep -v [.]h$$ | grep -v [.]sql$$ |xargs rm -rf #makefile
[root@localhost MYSQL]# ls
dbproc.c demo.c makefile
[root@localhost MYSQL]# make
[root@localhost MYSQL]# ./demo
Connection failed!
Connection error 2002: Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)!
启动 MySQL： [确定]
MySQL Connection success!
iRetCode = 0
[root@localhost MYSQL]#
DB2下
//dbproc.sqc
/*************************************************************
FileName : dbproc.sqc
FileFunc : C语言接口访问本地DB2数据库
Version : V0.1
Author : Sunrier
Date : 2012-06-15
Descp : Linux下使用C语言访问DB2函数
*************************************************************/
//(嵌入SQL语句的关键字不区分大小写)
#include <stdio.h>
#include <string.h>
#include <sqlca.h>
#define PARAERR 0x04
#define DATABASEERR 0x08
EXEC SQL include sqlca;
int check_error(char szMessage[])
{
if( sqlca.sqlcode )
{
printf("Check error report : \n");
printf("Error occured : %s ,sqlcode = [%d] \n",szMessage,sqlca.sqlcode);
return 1;
}
return 0;
}
int db2_login(int iArgcFlag,char *pUserName,char *pPassword,char *pDataBase)
{
int iRetCode = 1;
EXEC SQL BEGIN DECLARE SECTION;
char szUserName[50];
char szPassword[50];
char szDataBase[50];
EXEC SQL END DECLARE SECTION;
memset(szUserName,0,sizeof(szUserName));
memset(szPassword,0,sizeof(szPassword));
memset(szDataBase,0,sizeof(szDataBase));
strcpy(szDataBase,pDataBase);
if( 1==iArgcFlag )
{
EXEC SQL CONNECT TO:szDataBase ;
}
else
{
if( 3==iArgcFlag )
{
strcpy(szUserName,pUserName);
strcpy(szPassword,pPassword);
EXEC SQL CONNECT TO:szDataBase USER:szUserName USING:szPassword;
}
else
{
printf("Usage : argc found error !\n");
return PARAERR;
}
}
iRetCode = check_error("CONNECT TO DATABASE");
return iRetCode;
}
void db2_logout( void )
{
EXEC SQL CONNECT RESET;
check_error("CONNECT RESET");
}
//demo.c
/*************************************************************
FileName : demo.c
FileFunc : 测试登陆和关闭DB2数据库
Version : V0.1
Author : Sunrier
Date : 2012-06-15
Descp : Linux下使用C语言访问DB2函数
*************************************************************/
#include <stdio.h>
int main(int argc,char *argv[])
{
int iRetCode = 0;
int iArgcFlag;
char szUserName[20] = "Sunrier";
char szPassword[20] = "redhat";
char szDatabase[20] = "test";
iArgcFlag = 3;
iRetCode = db2_login(iArgcFlag,szUserName,szPassword,szDatabase);
printf("iRetCode = %d \n",iRetCode);
if( iRetCode )
{
printf("DB2 Connection failure !\n");
return iRetCode;
}
else
{
printf("DB2 Connection success !\n");
}
db2_logout();
return 0;
}
//makefile
all:demo DB2INCPATH=/home/db2inst1/sqllib/include DB2LIBPATH=/home/db2inst1/sqllib/lib demo:demo.c dbproc.sqc @db2 connect to test @db2 prep dbproc.sqc @gcc -ldb2 -L/usr/lib -lm -o demo demo.c dbproc.c # @gcc -L/home/db2inst1/sqllib/lib -ldb2 -L/usr/lib -lm -o demo dbproc.c clean: @ls | grep -v ^makefile$$ | grep -v [.]c$$ | grep -v [.]h$$ | grep -v [.]sqc$$ | grep -v [.]sql$$ |xargs rm -rf #@db2start //数据库的启动 #@db2stop //数据库的停止 #db2 connect to test //连接test数据库 #db2 prep dbproc.sqc bindfile //prep命令生成.c文件和.bnd文件( 加bindfile选项 ) #db2 bind dbproc.bnd //bind命令生成PACKET #gcc -L/home/db2inst1/sqllib/lib -ldb2 -L/usr/lib -lm -o test test.c //生成可执行文件 #@db2 -r rep.rpt prep dbproc.sqc //把db2 prep dbproc.sqc执行后的信息输出保存到rep.rpt报告文件中(-r的作用将输出保存到报告文件) #@db2 +o prep dbproc.sqc //不显示db2 prep dbproc.sqc执行后的信息(+o的作用为不显示执行信息) ## Disconnect from the database. #@db2 connect reset//db2 disconnect current//断开数据库连接,后台db2bp依然存在 #@db2 terminate //断开数据库连接,干掉db2bp
[Sunrier@localhost DB2]$ ls
dbproc.sqc demo.c makefile
[Sunrier@localhost DB2]$ make
Database Connection Information
Database server = DB2/LINUX 8.2.3
SQL authorization ID = Sunrier
Local database alias = TEST
LINE MESSAGES FOR dbproc.sqc
------ --------------------------------------------------------------------
SQL0060W The "C" precompiler is in progress.
SQL0091W Precompilation or binding was ended with "0"
errors and "0" warnings.
[Sunrier@localhost DB2]$ ls
dbproc.c dbproc.sqc demo demo.c makefile
[Sunrier@localhost DB2]$ ./demo
iRetCode = 0
DB2 Connection success !
[Sunrier@localhost DB2]$
Informix下
//informixdbproc.ec
/*************************************************************
FileName : informixdbproc.ec
FileFunc : C语言接口访问Informix数据库
Version : V0.1
Author : Sunrier
Date : 2012-07-27
Descp : Linux下使用C语言访问Informix函数
*************************************************************/
#include <stdio.h>
#include <string.h>
EXEC SQL include sqlca;
int check_error(char szMessage[])
{
if( sqlca.sqlcode )
{
printf("Check error report : \n");
printf("Error occured : %s ,sqlcode = [%d] \n",szMessage,sqlca.sqlcode);
return 1;
}
return 0;
}
int informix_login(char *pDataBase)
{
int iRetCode = 1;
EXEC SQL BEGIN DECLARE SECTION;
char szDataBase[30];
EXEC SQL END DECLARE SECTION;
memset(szDataBase,0,sizeof(szDataBase));
strcpy(szDataBase,pDataBase);
EXEC SQL CONNECT TO:szDataBase ;
iRetCode = check_error("CONNECT TO DATABASE");
return iRetCode;
}
int informix_logout(char *pDataBase)
{
int iRetCode = 1;
EXEC SQL BEGIN DECLARE SECTION;
char szDataBase[50+1];
EXEC SQL END DECLARE SECTION;
memset(szDataBase,0,sizeof(szDataBase));
strncpy(szDataBase,pDataBase,50);
EXEC SQL DISCONNECT :szDataBase;
iRetCode = check_error("DisConnect");
return iRetCode;
}
int informix_logout_ex( void )
{
int iRetCode = 1;
EXEC SQL DISCONNECT CURRENT;
iRetCode = check_error("CONNECT RESET");
return iRetCode;
}
//demo.c
/*************************************************************
FileName : demo.c
FileFunc : 测试登陆和关闭本地Informix数据库
Version : V0.1
Author : Sunrier
Date : 2012-07-27
Descp : Linux下使用C语言访问Informix函数
*************************************************************/
#include <stdio.h>
int main(int argc,char *argv[])
{
int iRetCode = 0;
char szDatabase[30] = "test";
iRetCode = informix_login(szDatabase);
printf("iRetCode = %d \n",iRetCode);
if( iRetCode )
{
printf("Informix Connection failure !\n");
}
else
{
printf("Informix Connection success !\n");
}
/*informix_logout(szDatabase); */
return 0;
}
//makefile
#makefile OBJS = demo all:$(OBJS) CFLAGS = -O -w -ansi #CFLAGS = -O -Wall -ansi CC = gcc $(CFLAGS) $PATH=$PATH:$HOME/bin:/home/informix/bin:$HOME/sbin: export PATH unset USERNAME INFORMIXDIR=/home/informix ONCONFIG=onconfig INFORMIXSERVER=online LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$INFORMIXDIR/lib:$INFORMIXDIR/lib/esql export INFORMIXDIR INFORMIXSERVER ONCONFIG LD_LIBRARY_PATH DB_LOCALE=zh_CN.gb CLIENT_LOCALE=zh_CN.gb SERVER_LOCALE=zh_CN.gb export DB_LOCALE CLIENT_LOCALE SERVER_LOCALE export LD_ASSUME_KERNEL=2.4.1 PATH=$INFORMIXDIR/bin:$PATH export PATH LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$HOME/src/lib export LD_LIBRARY_PATH TERMCAP=$INFORMIXDIR/etc/Termcap export TERMCAP ETCPATH=$HOME/etc export ETCPATH #Set system path MAINPATH=$(HOME) SRCPATH=$(MAINPATH)/src BINPATH=$(MAINPATH)/bin SYSINCLPATH=$(MAINPATH)/include SYSLIBPATH=$(MAINPATH)/lib APPINCLPATH=$(SRCPATH)/include APPLIBPATH=$(SRCPATH)/lib #EC = esql -I$(SYSINCLPATH) -I$(APPINCLPATH) -L$(SYSLIBPATH) -L$(APPLIBPATH) EC = esql INFORMIXLINCPATH = -I/home/informix/bin INFORMIXLIBPATH = -L/usr/lib/informix INFORMIXLIB = -lm demo:demo.c informixdbproc.ec @echo -e "Start compile Informix file ...... " @$(EC) -o demo demo.c informixdbproc.ec #$(EC) -o demo demo.c informixdbproc.ec 不会生成informixdbproc.o文件,只生成informixdbproc.c文件 #或者 #$(EC) -c informixdbproc.ec 会生成.c和.o文件执行后会生成informixdbproc.c和informixdbproc.o这两个文件 #@$(EC) -c informixdbproc.ec #$(EC) -o demo demo.c informixdbproc.c 生成可执行文件 #@$(EC) -o demo demo.c informixdbproc.c #或$(EC) -o demo demo.c informixdbproc.o 生成可执行文件 #@$(EC) -o demo demo.c informixdbproc.o # 其中$(EC) -o demo demo.c informixdbproc.c和$(EC) -o demo demo.c informixdbproc.o一样 #或者使用后缀方式 #.SUFFIXES: .ec #demo:demo.o informixdbproc.o # @$(EC) -o $@ $? #.c.o: # @$(CC) -c $< #.ec.o: # @$(EC) -c $< # @rm -f $*.c clean: @rm -rf informixdbproc.c @ls | grep -v ^makefile$$ | grep -v [.]c$$ | grep -v [.]h$$ | grep -v [.]sql$$ | grep -v [.]ec$$ | xargs rm -rf #makefile
[Sunrier@localhost Informix]$ ls
demo demo.c informixdbproc.ec makefile
[Sunrier@localhost Informix]$ make
Start compile Informix file ......
[Sunrier@localhost Informix]$ ls
demo demo.c informixdbproc.c informixdbproc.ec makefile
[Sunrier@localhost Informix]$ ./demo
iRetCode = 0
Informix Connection success !
[Sunrier@localhost Informix]$
Oracle下
//oracledbproc.pc
/*************************************************************
FileName : oracledbproc.pc
FileFunc : C语言接口访问Oracle数据库
Version : V0.1
Author : Sunrier
Date : 2012-07-27
Descp : Linux下使用C语言访问Oracle函数
*************************************************************/
#include <stdio.h>
#include <string.h>
EXEC SQL include sqlca;
int check_error(char szMessage[])
{
if( sqlca.sqlcode )
{
printf("Check error report : \n");
printf("Error occured : %s ,sqlcode = [%d] \n",szMessage,sqlca.sqlcode);
return 1;
}
return 0;
}
int oracle_login(char *pUserName,char *pPassword,char *pDataBase)
{
int iRetCode = 1;
EXEC SQL BEGIN DECLARE SECTION;
char szUserName[30];
char szPassword[30];
char szDataBase[30];
EXEC SQL END DECLARE SECTION;
memset(szUserName,0,sizeof(szUserName));
memset(szPassword,0,sizeof(szPassword));
memset(szDataBase,0,sizeof(szDataBase));
strcpy(szUserName,pUserName);
strcpy(szPassword,pPassword);
strcpy(szDataBase,pDataBase);
EXEC SQL CONNECT :szUserName identified by :szPassword using :szDataBase;
iRetCode = check_error("CONNECT TO DATABASE");
return iRetCode;
}
int oracle_logout( void )
{
int iRetCode = 1;
EXEC SQL commit work release;
iRetCode = check_error("DisConnect TO DATABASE");
return iRetCode;
}
//demo.c
/*************************************************************
FileName : demo.c
FileFunc : 测试登陆和关闭本地Oracle数据库
Version : V0.1
Author : Sunrier
Date : 2012-07-27
Descp : Linux下使用C语言访问Oracle函数
*************************************************************/
#include <stdio.h>
int main(int argc,char *argv[])
{
int iRetCode = 0;
char szUserName[20] = "Sunrier";
char szPassword[20] = "redhat";
char szDatabase[20] = "test";
iRetCode = oracle_login(szUserName,szPassword,szDatabase);
printf("iRetCode = %d \n",iRetCode);
if( iRetCode )
{
printf("Oracle Connection failure !\n");
return iRetCode;
}
else
{
printf("Oracle Connection success !\n");
}
iRetCode = oracle_logout();
return iRetCode;
}
//makefile
#makefile
OBJS = demo
all:$(OBJS)
PATH=$PATH:$HOME/bin:$MAINPATH/sbin:$MAINPATH/sql
export PATH
LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$HOME/runlib
export LD_LIBRARY_PATH
export LANG=zh_CN.gb2312
export LANG=zh_cn.gbk
#oracle setting
export NLS_LANG=AMERICAN_AMERICA.ZHS16GBK
TMP=/tmp; export TMP
TMPDIR=$TMP; export TMPDIR
ORACLE_BASE=/home/oracle; export ORACLE_BASE
ORACLE_HOME=$ORACLE_BASE/product/10.2/db_1; export ORACLE_HOME
ORACLE_SID=Sunrier; export ORACLE_SID
ORACLE_TERM=xterm; export ORACLE_TERM
PATH=/usr/sbin:$PATH; export PATH
PATH=$ORACLE_HOME/bin:$PATH; export PATH
LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$ORACLE_HOME/lib:/lib:/usr/lib; export LD_LIBRARY_PATH
CLASSPATH=$ORACLE_HOME/JRE:$ORACLE_HOME/jlib:$ORACLE_HOME/rdbms/jlib; export CLASSPATH
CFLAGS = -O -w -ansi
#CFLAGS = -O -Wall -ansi
CC = gcc $(CFLAGS)
#Set system path
#运行动态库路径
RUNLIBPATH=$(HOME)/runlib
#主路径
MAINPATH=$(HOME)/Proj
#库头文件
SYSINCLPATH=$(MAINPATH)/include
#执行文件
BINPATH=$(HOME)/bin
#源程序路径
SRCPATH=$(MAINPATH)/src
APPINCLPATH=$(SRCPATH)/include
#PROCFLAGS= \
# include=${ORACLE_HOME}/rdbms/public \
# include=$(SYSINCLPATH) \
# include=$(APPINCLPATH) \
# parse=full \
# unsafe_null=yes \
# dbms=V8 \
# mode=oracle \
# lines=yes \
# char_map=string
#proc用来对Oracle源程序.pc进行预编译,生成单纯的C源程序
#PROC= proc $(PROCFLAGS)
PROC= proc
ORALIB=-L$(ORACLE_HOME)/lib -lclntsh
demo:demo.c oracledbproc.pc
@echo -e "Start compile Oracle file ......"
@$(PROC) PARSE=NONE oracledbproc.pc
@$(CC) -o $@ demo.c oracledbproc.c $(ORALIB)
# @$(CC) -o $@ demo.c oracledbproc.c $(ORACLE_HOME)/lib/libclntsh.so
clean:
@rm -rf oracledbproc.c
@ls | grep -v ^makefile$$ | grep -v [.]c$$ | grep -v [.]h$$ | grep -v [.]sql$$ | grep -v [.]pc$$ | xargs rm -rf
#makefile
[Sunrier@localhost Oracle]$ ls
demo.c makefile oracledbproc.pc
[Sunrier@localhost Oracle]$ make
Start compile Oracle file ......
Pro*C/C++: Release 10.2.0.5.0 - Production on Fri Jul 27 16:31:30 2012
Copyright (c) 1982, 2007, Oracle. All rights reserved.
System default option values taken from: /home/oracle/product/10.2/db_1/precomp/admin/pcscfg.cfg
[Sunrier@localhost Oracle]$ ls
demo demo.c makefile oracledbproc.c oracledbproc.lis oracledbproc.pc
[Sunrier@localhost Oracle]$ ./demo
iRetCode = 0
Oracle Connection success !
[Sunrier@localhost Oracle]$