C語(yǔ)言和Oracle數(shù)據(jù)庫(kù)結(jié)合起來(lái)，可以實(shí)現(xiàn)強(qiáng)大的功能，為企業(yè)級(jí)應(yīng)用提供行業(yè)標(biāo)準(zhǔn)的用戶(hù)界面。C語(yǔ)言的高級(jí)、可移植特性與Oracle數(shù)據(jù)庫(kù)的安全、性能穩(wěn)定性被結(jié)合在一起，可以讓開(kāi)發(fā)者更高效、精確地構(gòu)建數(shù)據(jù)驅(qū)動(dòng)型應(yīng)用程序。 使用C語(yǔ)言調(diào)用Oracle提供的API接口，可以輕松地執(zhí)行數(shù)據(jù)庫(kù)查詢(xún)、更新、刪除等操作。用戶(hù)可以通過(guò)C語(yǔ)言和Oracle數(shù)據(jù)庫(kù)進(jìn)行界面處理。下面是一個(gè)示例，演示了如何在C語(yǔ)言中訪(fǎng)問(wèn)Oracle數(shù)據(jù)庫(kù)并顯示數(shù)據(jù)：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <oci.h>
#define MAX_BUF 100
void checkerr(OCIError *errhp, sword status)
{
text errbuf[MAX_BUF];
ub4 buflen;
sb4 errcode;
switch (status)
{
case OCI_SUCCESS:
break;
case OCI_SUCCESS_WITH_INFO:
printf("Error - OCI_SUCCESS_WITH_INFO\n");
break;
case OCI_NEED_DATA:
printf("Error - OCI_NEED_DATA\n");
break;
case OCI_NO_DATA:
printf("Error - OCI_NO_DATA\n");
break;
case OCI_ERROR:
OCIErrorGet ((dvoid *) errhp, (ub4) 1, (text *) NULL, &errcode,
errbuf, (ub4) sizeof(errbuf), OCI_HTYPE_ERROR);
printf("Error - %.*s\n", 512, errbuf);
break;
case OCI_INVALID_HANDLE:
printf("Error - OCI_INVALID_HANDLE\n");
break;
case OCI_STILL_EXECUTING:
printf("Error - OCI_STILL_EXECUTE\n");
break;
case OCI_CONTINUE:
printf("Error - OCI_CONTINUE\n");
break;
default:
break;
}
}
int main(int argc, char *argv[])
{
OCIEnv *envhp;
OCIServer *srvhp;
OCIError *errhp;
OCISession *sesshp;
OCIStmt *stmthp;
OCIDefine *defnp;
ub4 htype = OCI_HTYPE_STMT;
sb4 status;
text username[MAX_BUF], password[MAX_BUF], dbname[MAX_BUF];
strcpy((char *) username, "your_username");
strcpy((char *) password, "your_password");
strcpy((char *) dbname, "your_dbname");
OCIInitialize ((ub4) OCI_DEFAULT, (dvoid *) 0, (dvoid * (*)(dvoid *, size_t)) 0,
(dvoid * (*)(dvoid *, dvoid *, size_t)) 0, (void (*)(dvoid *, dvoid *)) 0 );
OCIEnvInit ((OCIEnv **) &envhp, OCI_DEFAULT, (size_t) 0, (dvoid **) 0 );
OCIHandleAlloc ((dvoid *) envhp, (dvoid **) &errhp, OCI_HTYPE_ERROR, (size_t) 0, (dvoid **) 0);
OCIHandleAlloc ((dvoid *) envhp, (dvoid **) &srvhp, OCI_HTYPE_SERVER, (size_t) 0, (dvoid **) 0);
OCIHandleAlloc ((dvoid *) envhp, (dvoid **) &sesshp, OCI_HTYPE_SESSION, (size_t) 0, (dvoid **) 0);
OCIHandleAlloc ((dvoid *) envhp, (dvoid **) &stmthp, OCI_HTYPE_STMT, (size_t) 0, (dvoid **) 0);
OCIServerAttach (srvhp, errhp, (text *) dbname, (sb4) strlen((char *) dbname), OCI_DEFAULT);
OCIAttrSet ((dvoid *) sesshp, (ub4) OCI_HTYPE_SESSION, (dvoid *) username,
(ub4) strlen ((char *) username), OCI_ATTR_USERNAME, errhp);
OCIAttrSet ((dvoid *) sesshp, (ub4) OCI_HTYPE_SESSION, (dvoid *) password,
(ub4) strlen ((char *) password), OCI_ATTR_PASSWORD, errhp);
status = OCISessionBegin (srvhp, errhp, sesshp, OCI_CRED_RDBMS, OCI_DEFAULT);
checkerr(errhp, status);
OCIStmtPrepare(stmthp, errhp, (text *) "SELECT * FROM MYTABLE", (ub4) strlen((char *) "SELECT * FROM MYTABLE"),
(ub4) OCI_NTV_SYNTAX, (ub4) OCI_DEFAULT);
status = OCIStmtExecute((OCISvcCtx *) sesshp, stmthp, errhp, (ub4) 0, (ub4) 0,
(CONST OCISnapshot *) NULL, (OCISnapshot *) NULL, OCI_DEFAULT);
checkerr(errhp, status);
OCIHandleAlloc ((dvoid *)envhp, (dvoid **)&defnp, OCI_HTYPE_DEFINE, (size_t)0, (dvoid **) 0);
OCIStmtGetPieceInfo(stmthp, errhp, &htype, &defnp, (ub4 *)&status, OCI_PIECE_DEFINE, OCI_DEFAULT);
printf("Data from MYTABLE:\n");
while(status != OCI_NO_DATA)
{
status = OCIStmtFetch(stmthp, errhp, 1, OCI_FETCH_NEXT, OCI_DEFAULT);
if(status == OCI_NO_DATA)
break;
printf("%-20s %-20s %-20s\n", text1, text2, text3);
}
OCISessionEnd(sesshp, errhp, srvhp, OCI_DEFAULT);
OCIServerDetach(srvhp, errhp, OCI_DEFAULT);
OCIHandleFree((dvoid *) envhp, OCI_HTYPE_ENV);
OCIHandleFree((dvoid *) errhp, OCI_HTYPE_ERROR);
OCIHandleFree((dvoid *) srvhp, OCI_HTYPE_SERVER);
OCIHandleFree((dvoid *) sesshp, OCI_HTYPE_SESSION);
OCIHandleFree((dvoid *) stmthp, OCI_HTYPE_STMT);
return 0;
}

上述代碼演示了如何使用C語(yǔ)言和Oracle數(shù)據(jù)庫(kù)交互的過(guò)程，展現(xiàn)了如何使用OCI進(jìn)行連接、數(shù)據(jù)庫(kù)操作，并最終獲取數(shù)據(jù)庫(kù)中的數(shù)據(jù)并進(jìn)行顯示。可以看到，C語(yǔ)言與Oracle數(shù)據(jù)庫(kù)相結(jié)合可以實(shí)現(xiàn)豐富的應(yīng)用程序功能，提升企業(yè)應(yīng)用程序的性能，穩(wěn)定性和安全性，滿(mǎn)足企業(yè)需求。