對于C程序員來說,執(zhí)行Oracle存儲過程是常見需求之一,今天我們就來詳細介紹如何通過C程序執(zhí)行Oracle存儲過程。
首先,我們需要連接到Oracle數(shù)據(jù)庫。可以使用OCI庫提供的函數(shù)進行連接,例如:
OCIEnv *envhp; OCIError *errhp; OCISvcCtx *svchp; OCIStmt *stmthp; OCIServer *srvhp; OCIAuthInfo *auth; OCIType *type; OCIDefine *defnp; OCIBind *bindp; OCIErrorGet(&envhp, 0, (const OraText **)0, &errhp); OCIHandleAlloc(envhp, (dvoid **)&srvhp, OCI_HTYPE_SERVER, 0, (dvoid **)0); OCIHandleAlloc(envhp, (dvoid **)&auth, OCI_HTYPE_AUTHINFO, 0, (dvoid **)0); OCIAttrSet(auth, OCI_HTYPE_AUTHINFO, (dvoid *)"username", (ub4)strlen("username"), OCI_ATTR_USERNAME, errhp); OCIAttrSet(auth, OCI_HTYPE_AUTHINFO, (dvoid *)"password", (ub4)strlen("password"), OCI_ATTR_PASSWORD, errhp); OCIAttrSet(auth, OCI_HTYPE_AUTHINFO, (dvoid *)"dbname", (ub4)strlen("dbname"), OCI_ATTR_DATABASE_NAME, errhp); OCIHandleAlloc(envhp, (dvoid **)&svchp, OCI_HTYPE_SVCCTX, 0, (dvoid **)0); OCIAttrSet(svchp, OCI_HTYPE_SVCCTX, (dvoid *)srvhp, (ub4)0, OCI_ATTR_SERVER, errhp); OCIAttrSet(svchp, OCI_HTYPE_SVCCTX, (dvoid *)auth, (ub4)0, OCI_ATTR_AUTHINFO, errhp); OCIHandleAlloc(envhp, (dvoid **)&stmthp, OCI_HTYPE_STMT, 0, (dvoid **)0); OCILogon(envhp, errhp, &svchp, (OraText *)"username", strlen("username"), (OraText *)"password", strlen("password"), (OraText *)"dbname", strlen("dbname"));
連接成功后,我們需要通過OCIStmtPrepare函數(shù)準備存儲過程的SQL語句:
char *sql = "begin my_procedue(); end;"; OCIStmtPrepare(stmthp, errhp, (const OraText *)sql, (ub4)strlen(sql), OCI_NTV_SYNTAX, OCI_DEFAULT);
注意,在SQL語句中需要指定存儲過程的名稱。如果存儲過程需要參數(shù),可以通過OCIBindByName函數(shù)綁定參數(shù):
int arg1 = 10, arg2 = 20; OCIBindByName(stmthp, &bindp, errhp, (const OraText *)":arg1", (sb4)strlen(":arg1"), (dvoid *)&arg1, (sb4)sizeof(int), SQLT_INT, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)0, (ub4 *)0, OCI_DEFAULT); OCIBindByName(stmthp, &bindp, errhp, (const OraText *)":arg2", (sb4)strlen(":arg2"), (dvoid *)&arg2, (sb4)sizeof(int), SQLT_INT, (dvoid *)0, (ub2 *)0, (ub2 *)0, (ub4)0, (ub4 *)0, OCI_DEFAULT);
綁定參數(shù)后,我們可以調(diào)用OCIStmtExecute函數(shù)執(zhí)行存儲過程:
OCIStmtExecute(svchp, stmthp, errhp, (ub4)1, (ub4)0, (CONST OCISnapshot *)NULL, (OCISnapshot *)NULL, OCI_DEFAULT);
最后,我們需要通過OCIStmtFetch函數(shù)獲取存儲過程的結(jié)果:
int result; OCINumber result_number; OCIStmtFetch(stmthp, errhp, (ub4)1, OCI_FETCH_NEXT, OCI_DEFAULT); OCINumberFromInt(errhp, &result, sizeof(result), OCI_NUMBER_SIGNED, &result_number); OCINumberToInt(errhp, &result_number, sizeof(result), OCI_NUMBER_SIGNED, &result); printf("Stored procedure returned %d\n", result);
上面的代碼中,我們假設(shè)存儲過程返回一個整數(shù)值。
總之,通過以上步驟,我們就可以輕松地在C程序中執(zhí)行Oracle存儲過程了。