c 调用oracle连接

C语言是一种功能强大的编程语言，与Oracle数据库相结合，可以为大型企业应用程序提供持久性的数据存储和访问。本文将介绍如何使用C语言中的OCI（Oracle Call Interface）库来连接Oracle数据库。我们将通过几个简单的例子来演示如何使用这个强大的工具。

在使用OCI库连接Oracle数据库之前，我们需要先安装Oracle客户端软件。请注意，Oracle客户端安装程序可能会根据你的系统和版本进行微调，因此你需要确保安装的Oracle客户端与你的操作系统和Oracle数据库版本兼容。一旦Oracle客户端安装完毕，我们就可以开始编写代码了。

#include#include#includevoid checkerr(OCIError *errhp, sword status) { text errbuf[512]; sb4 errcode; if (status == OCI_SUCCESS) return; else if (status == OCI_ERROR) { OCIErrorGet((dvoid *)errhp, (ub4)1, (text *)NULL, &errcode, errbuf, (ub4)sizeof(errbuf), OCI_HTYPE_ERROR); printf("Error: %.*s\n", 512, errbuf); exit(1); } } int main() { OCIEnv *envhp; OCIError *errhp; OCISvcCtx *svchp; OCIStmt *stmthp; OCIDefine *defnp = (OCIDefine *)0; sword status; 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, 0, (dvoid **)0); OCIHandleAlloc((dvoid *)envhp, (dvoid **)&errhp, OCI_HTYPE_ERROR, (size_t)0, (dvoid **)0); OCIHandleAlloc((dvoid *)envhp, (dvoid **)&svchp, OCI_HTYPE_SVCCTX, (size_t)0, (dvoid **)0); status = OCILogon(envhp, errhp, &svchp, "user", strlen("user"), "password", strlen("password"), "database", strlen("database")); checkerr(errhp, status); OCIHandleAlloc((dvoid *)envhp, (dvoid **)&stmthp, OCI_HTYPE_STMT, (size_t)0, (dvoid **)0); OCIStmtPrepare(stmthp, errhp, (text *)"SELECT * FROM employees", strlen("SELECT * FROM employees"), OCI_NTV_SYNTAX, OCI_DEFAULT); checkerr(errhp, OCIStmtExecute(svchp, stmthp, errhp, (ub4)0, (ub4)0, (OCISnapshot *)NULL, (OCISnapshot *)NULL, OCI_DEFAULT)); OCIHandleFree((dvoid *)stmthp, OCI_HTYPE_STMT); OCILogoff(svchp, errhp); OCIHandleFree((dvoid *)svchp, OCI_HTYPE_SVCCTX); OCIHandleFree((dvoid *)errhp, OCI_HTYPE_ERROR); OCIHandleFree((dvoid *)envhp, OCI_HTYPE_ENV); return 0; }