oracle下的odbc编程

只说下碰到的几个问题：

1.unixODBC版本不一致的问题。

oracle选择的是oracle11gR2，与之版本一致的UnixODBC版本是2.2.14，最新的2.3.4是不行的。如果选择2.3.4在用isql测试连接的时候会提示：

[08004][unixODBC][Oracle][ODBC][Ora]ORA-12154: TNS:could not resolve the connect identifier specified

[ISQL]ERROR: Could not SQLConnect

2.数据源首先查找系统dsn，找不到再查找用户dsn

3.连接远端oracle服务需要配置正确的tnsname，.odbc.ini中的 ServerName = 【网络服务名tnsname】

4.oracle自带的unixODBC默认查找位置为/etc

5.用unixodbc官网提供的查询示例进行查询测试。gcc query.c –o query –I/$(指定)/incude –L$(指定)/lib –lodbc

6.依赖关系：libodbc.so动态打开驱动 libsqora.so.11.1，驱动libsqora.so.11.1依赖libodbcinst.so

isql依赖libodbc.so，间接依赖驱动libsqora.so.11.1(动态打开的)。

c客户端依赖libodbc.so，间接依赖驱动libsqora.so.11.1(动态打开的)。

7.query.c源码：

#include <stdlib.h>
#include <stdio.h>
#include <sql.h>
#include <sqlext.h>
#include <sqltypes.h>

SQLHENV			 V_OD_Env;			// Handle ODBC environment
long			 V_OD_erg;			// result of functions
SQLHDBC			 V_OD_hdbc;			// Handle connection

char			 V_OD_stat[10];		// Status SQL
SQLINTEGER		V_OD_err;
SQLLEN		V_OD_len;
SQLINTEGER		 V_OD_id;
SQLLEN V_OD_rowanz;
SQLSMALLINT		 V_OD_mlen,V_OD_colanz;
char             V_OD_msg[200],V_OD_buffer[200];
SQLHSTMT V_OD_hstmt;


int main(int argc,char *argv[])
{
	V_OD_erg=SQLAllocHandle(SQL_HANDLE_ENV,SQL_NULL_HANDLE,&V_OD_Env);
	if ((V_OD_erg != SQL_SUCCESS) && (V_OD_erg != SQL_SUCCESS_WITH_INFO))
	{
		printf("Error AllocHandle\n");
		exit(0);
	}
	V_OD_erg=SQLSetEnvAttr(V_OD_Env, SQL_ATTR_ODBC_VERSION, (void*)SQL_OV_ODBC3, 0); 
	if ((V_OD_erg != SQL_SUCCESS) && (V_OD_erg != SQL_SUCCESS_WITH_INFO))
	{
		printf("Error SetEnv\n");
		SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);
		exit(0);
	}
	V_OD_erg = SQLAllocHandle(SQL_HANDLE_DBC, V_OD_Env, &V_OD_hdbc); 
	if ((V_OD_erg != SQL_SUCCESS) && (V_OD_erg != SQL_SUCCESS_WITH_INFO))
	{
		printf("Error AllocHDB %d\n",V_OD_erg);
		SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);
		exit(0);
	}
	SQLSetConnectAttr(V_OD_hdbc, SQL_LOGIN_TIMEOUT, (SQLPOINTER *)5, 0);
	V_OD_erg = SQLConnect(V_OD_hdbc, (SQLCHAR*) "zyx", SQL_NTS,
                                     (SQLCHAR*) "cbadevdb", SQL_NTS,
                                     (SQLCHAR*) "cbadevdb", SQL_NTS);
	if ((V_OD_erg != SQL_SUCCESS) && (V_OD_erg != SQL_SUCCESS_WITH_INFO))
	{
		printf("Error SQLConnect %d\n",V_OD_erg);
		SQLGetDiagRec(SQL_HANDLE_DBC, V_OD_hdbc,1, 
		              V_OD_stat, &V_OD_err,V_OD_msg,100,&V_OD_mlen);
		printf("%s (%d)\n",V_OD_msg,V_OD_err);
		SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);
		exit(0);
	}
	printf("Connected !\n");
	V_OD_erg=SQLAllocHandle(SQL_HANDLE_STMT, V_OD_hdbc, &V_OD_hstmt);
	if ((V_OD_erg != SQL_SUCCESS) && (V_OD_erg != SQL_SUCCESS_WITH_INFO))
	{
		printf("Fehler im AllocStatement %d\n",V_OD_erg);
		SQLGetDiagRec(SQL_HANDLE_DBC, V_OD_hdbc,1, V_OD_stat,&V_OD_err,V_OD_msg,100,&V_OD_mlen);
		printf("%s (%d)\n",V_OD_msg,V_OD_err);
        SQLDisconnect(V_OD_hdbc);
        SQLFreeHandle(SQL_HANDLE_DBC,V_OD_hdbc);
		SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);
		exit(0);
	}
    SQLBindCol(V_OD_hstmt,1,SQL_C_CHAR, &V_OD_buffer,150,&V_OD_len);
    SQLBindCol(V_OD_hstmt,2,SQL_C_ULONG,&V_OD_id,150,&V_OD_len);
	
    V_OD_erg=SQLExecDirect(V_OD_hstmt,"SELECT name,id FROM stu order by id",SQL_NTS);   
    if ((V_OD_erg != SQL_SUCCESS) && (V_OD_erg != SQL_SUCCESS_WITH_INFO))
    {
       printf("Error in Select %d\n",V_OD_erg);
       SQLGetDiagRec(SQL_HANDLE_DBC, V_OD_hdbc,1, V_OD_stat,&V_OD_err,V_OD_msg,100,&V_OD_mlen);
       printf("%s (%d)\n",V_OD_msg,V_OD_err);
       SQLFreeHandle(SQL_HANDLE_STMT,V_OD_hstmt);
       SQLDisconnect(V_OD_hdbc);
       SQLFreeHandle(SQL_HANDLE_DBC,V_OD_hdbc);
       SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);
       exit(0);
    }
    V_OD_erg=SQLNumResultCols(V_OD_hstmt,&V_OD_colanz);
    if ((V_OD_erg != SQL_SUCCESS) && (V_OD_erg != SQL_SUCCESS_WITH_INFO))
    {
        SQLFreeHandle(SQL_HANDLE_STMT,V_OD_hstmt);
        SQLDisconnect(V_OD_hdbc);
        SQLFreeHandle(SQL_HANDLE_DBC,V_OD_hdbc);
        SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);
        exit(0);
    }
    printf("Number of Columns %d\n",V_OD_colanz);
    V_OD_erg=SQLRowCount(V_OD_hstmt,&V_OD_rowanz);
    if ((V_OD_erg != SQL_SUCCESS) && (V_OD_erg != SQL_SUCCESS_WITH_INFO))
    {
      printf("Number ofRowCount %d\n",V_OD_erg);
      SQLFreeHandle(SQL_HANDLE_STMT,V_OD_hstmt);
      SQLDisconnect(V_OD_hdbc);
      SQLFreeHandle(SQL_HANDLE_DBC,V_OD_hdbc);
      SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);
      exit(0);
    }
    printf("Number of Rows %d,%d\n",V_OD_rowanz,V_OD_erg);
    V_OD_erg=SQLFetch(V_OD_hstmt);  
    while(V_OD_erg != SQL_NO_DATA)
    {
     printf("Result: %d %s\n",V_OD_id,V_OD_buffer);
     V_OD_erg=SQLFetch(V_OD_hstmt);  
    }  ;
    SQLFreeHandle(SQL_HANDLE_STMT,V_OD_hstmt);
    SQLDisconnect(V_OD_hdbc);
    SQLFreeHandle(SQL_HANDLE_DBC,V_OD_hdbc);
    SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);
    return(0);
}