c快速操作oracle数据库（c# 操作oracle）

C语言是一种高效的编程语言，被广泛应用于各种领域。当需要在C语言中操作Oracle数据库时，可以使用Oracle提供的OCI（Oracle Call Interface）库。OCI库提供了一组接口函数，可以通过C语言快速地连接和操作Oracle数据库。本文将介绍OCI库的使用方法，并给出相关的示例代码。

1. 连接数据库

在使用OCI库操作Oracle数据库之前，首先需要建立连接。这可以通过OCI库提供的函数来实现。以下是一个简单的示例程序：

#include 
#include 
#include 
 
int mn()
{
    OCIEnv* envhp;
    OCIError* errhp;
    OCIServer* srvhp;
    OCISession* seshp;
    sword status;
 
    status = OCIEnvCreate(&envhp, OCI_DEFAULT, (void*)0, (void*(*)(void*, size_t))0,
         (void*(*)(void*, void*, size_t))0, (void(*)(void*, void*))0, 0, (void**)0);
    if (status != OCI_SUCCESS)
    {
        fprintf(stderr, "OCIEnvCreate fled!\n");
        exit(EXIT_FLURE);
    }
 
    status = OCIHandleAlloc((void*)envhp, (void**)&errhp, OCI_HTYPE_ERROR, (size_t)0, (void**)0);
    if (status != OCI_SUCCESS)
    {
        fprintf(stderr, "OCIHandleAlloc fled!\n");
        exit(EXIT_FLURE);
    }
 
    status = OCIHandleAlloc((void*)envhp, (void**)&srvhp, OCI_HTYPE_SERVER, (size_t)0, (void**)0);
    if (status != OCI_SUCCESS)
    {
        fprintf(stderr, "OCIHandleAlloc fled!\n");
        exit(EXIT_FLURE);
    }
 
    status = OCIHandleAlloc((void*)envhp, (void**)&seshp, OCI_HTYPE_SESSION, (size_t)0, (void**)0);
    if (status != OCI_SUCCESS)
    {
        fprintf(stderr, "OCIHandleAlloc fled!\n");
        exit(EXIT_FLURE);
    }
 
    status = OCILogon(envhp, errhp, &srvhp, (OraText*)"scott", (ub4)strlen("scott"), (OraText*)"tiger", (ub4)strlen("tiger"), (OraText*)"XE", (ub4)strlen("XE"));
    if (status != OCI_SUCCESS)
    {
        fprintf(stderr, "OCILogon fled!\n");
        exit(EXIT_FLURE);
    }
 
    return 0;
}

在这个程序中，我们使用OCIEnvCreate函数创建了一个OCI环境，然后使用OCIHandleAlloc函数分别创建了一个OCI错误句柄、OCI服务器句柄和OCI会话句柄。接着，使用OCILogon函数建立了到Oracle数据库的连接。在连接时需要指定用户名、密码和数据库实例名。

2. 执行SQL语句

建立连接之后，可以使用OCI库提供的函数执行SQL语句。以下是一个示例程序：

#include 
#include 
#include 
 
int mn()
{
    OCIEnv* envhp;
    OCIError* errhp;
    OCIServer* srvhp;
    OCISession* seshp;
    OCIStmt* stmthp;
    sword status;
 
    status = OCIEnvCreate(&envhp, OCI_DEFAULT, (void*)0, (void*(*)(void*, size_t))0,
         (void*(*)(void*, void*, size_t))0, (void(*)(void*, void*))0, 0, (void**)0);
    if (status != OCI_SUCCESS)
    {
        fprintf(stderr, "OCIEnvCreate fled!\n");
        exit(EXIT_FLURE);
    }
 
    status = OCIHandleAlloc((void*)envhp, (void**)&errhp, OCI_HTYPE_ERROR, (size_t)0, (void**)0);
    if (status != OCI_SUCCESS)
    {
        fprintf(stderr, "OCIHandleAlloc fled!\n");
        exit(EXIT_FLURE);
    }
 
    status = OCIHandleAlloc((void*)envhp, (void**)&srvhp, OCI_HTYPE_SERVER, (size_t)0, (void**)0);
    if (status != OCI_SUCCESS)
    {
        fprintf(stderr, "OCIHandleAlloc fled!\n");
        exit(EXIT_FLURE);
    }
 
    status = OCIHandleAlloc((void*)envhp, (void**)&seshp, OCI_HTYPE_SESSION, (size_t)0, (void**)0);
    if (status != OCI_SUCCESS)
    {
        fprintf(stderr, "OCIHandleAlloc fled!\n");
        exit(EXIT_FLURE);
    }
 
    status = OCILogon(envhp, errhp, &srvhp, (OraText*)"scott", (ub4)strlen("scott"), (OraText*)"tiger", (ub4)strlen("tiger"), (OraText*)"XE", (ub4)strlen("XE"));
    if (status != OCI_SUCCESS)
    {
        fprintf(stderr, "OCILogon fled!\n");
        exit(EXIT_FLURE);
    }
 
    status = OCIHandleAlloc((void*)envhp, (void**)&stmthp, OCI_HTYPE_STMT, (size_t)0, (void**)0);
    if (status != OCI_SUCCESS)
    {
        fprintf(stderr, "OCIHandleAlloc fled!\n");
        exit(EXIT_FLURE);
    }
 
    status = OCIStmtPrepare(stmthp, errhp, (OraText*)"SELECT * FROM emp WHERE empno = :1", (ub4)strlen("SELECT * FROM emp WHERE empno = :1"), OCI_NTV_SYNTAX, OCI_DEFAULT);
    if (status != OCI_SUCCESS)
    {
        fprintf(stderr, "OCIStmtPrepare fled!\n");
        exit(EXIT_FLURE);
    }
 
    int empno = 7369;
    status = OCIBindByPos(stmthp, (OCIBind**)&(empno), sizeof(int), SQLT_INT, (dvoid*)0, (ub2*)0, (ub2*)0, 0, (ub4*)0, 0, OCI_DEFAULT);
    if (status != OCI_SUCCESS)
    {
        fprintf(stderr, "OCIBindByPos fled!\n");
        exit(EXIT_FLURE);
    }
 
    status = OCIStmtExecute(seshp, stmthp, errhp, (ub4)1, (ub4)0, (OCISnapshot*)0, (OCISnapshot*)0, OCI_DEFAULT);
    if (status != OCI_SUCCESS)
    {
        fprintf(stderr, "OCIStmtExecute fled!\n");
        exit(EXIT_FLURE);
    }
 
    OCIStmt* resulthp = 0;
    status = OCIHandleAlloc((void*)envhp, (void**)&resulthp, OCI_HTYPE_STMT, (size_t)0, (void**)0);
    if (status != OCI_SUCCESS)
    {
        fprintf(stderr, "OCIHandleAlloc fled!\n");
        exit(EXIT_FLURE);
    }
 
    status = OCIStmtFetch2(stmthp, errhp, 1, OCI_FETCH_NEXT, 0, OCI_DEFAULT);
    if (status != OCI_SUCCESS && status != OCI_NO_DATA)
    {
        fprintf(stderr, "OCIStmtFetch2 fled!\n");
        exit(EXIT_FLURE);
    }
 
    if (status == OCI_SUCCESS)
    {
        int empno = 0;
        char ename[11] = { 0 };
        char job[10] = { 0 };
        int mgr = 0;
        char hiredate[12] = { 0 };
        int sal = 0;
        int comm = 0;
        int deptno = 0;
 
        OCIParam* paramhp;
        status = OCIAttrGet(stmthp, OCI_HTYPE_STMT, (void*)&paramhp, (ub4*)0, OCI_ATTR_PARAM, errhp);
        if (status != OCI_SUCCESS)
        {
            fprintf(stderr, "OCIAttrGet fled!\n");
            exit(EXIT_FLURE);
        }
 
        status = OCIParamGet(paramhp, OCI_DTYPE_PARAM, errhp, (void**)&resulthp, 1);
        if (status != OCI_SUCCESS)
        {
            fprintf(stderr, "OCIParamGet fled!\n");
            exit(EXIT_FLURE);
        }
 
        for (;;)
        {
            int i = 1;
            status = OCIStmtFetch2(stmthp, errhp, 1, OCI_FETCH_NEXT, 0, OCI_DEFAULT);
            if (status == OCI_NO_DATA)
            {
                break;
            }
 
            status = OCIAttrGet(resulthp, OCI_DTYPE_PARAM, &empno, 0, OCI_ATTR_DATA_TYPE, errhp);
            if (status != OCI_SUCCESS)
            {
                fprintf(stderr, "OCIAttrGet fled!\n");
                exit(EXIT_FLURE);
            }
 
            status = OCIAttrGet(resulthp, OCI_DTYPE_PARAM, ename, &i, OCI_ATTR_DATA_TYPE, errhp);
            if (status != OCI_SUCCESS)
            {
                fprintf(stderr, "OCIAttrGet fled!\n");
                exit(EXIT_FLURE);
            }
 
            status = OCIAttrGet(resulthp, OCI_DTYPE_PARAM, job, &i, OCI_ATTR_DATA