c oracle 查询数据

C语言是一门广泛使用的编程语言，而Oracle是一种强大的关系型数据库管理系统。在C语言中，查询数据库是非常常见的操作，许多应用程序都需要用C来查询Oracle数据库中存储的数据。本文将介绍如何在C语言中使用Oracle数据库进行数据查询，以及如何处理查询结果。下面我们来举一个例子说明查询的具体实现。

#include#include#includeint main() { OCISvcCtx *serviceContext; OCIEnv *environmentHandle; OCIError *errorHandle; OCIStmt *sqlStatement; OCIDefine *tableCol1; OCIDefine *tableCol2; OCILobLocator *lobLocator; char *sqlQuery; char col1[256]; char col2[256]; int i, j, k; int rowId; OCIEnvCreate(&environmentHandle, OCI_OBJECT, 0, 0, 0, 0, 0, 0); OCIHandleAlloc(environmentHandle, (void *)&errorHandle, OCI_HTYPE_ERROR, 0, 0); OCIHandleAlloc(environmentHandle, (void *)&serviceContext, OCI_HTYPE_SVCCTX, 0, 0); //这里省略了数据库连接细节 sqlQuery = "SELECT table_column1, table_column2 FROM table_name WHERE row_id = :1"; OCIHandleAlloc(environmentHandle, (void **)&sqlStatement, OCI_HTYPE_STMT, 0, 0); OCIStmtPrepare(sqlStatement, errorHandle, (text *)sqlQuery, strlen(sqlQuery), OCI_NTV_SYNTAX, OCI_DEFAULT); OCIHandleAlloc(environmentHandle, (void **)&tableCol1, OCI_HTYPE_DEFINE, 0, 0); OCIHandleAlloc(environmentHandle, (void **)&tableCol2, OCI_HTYPE_DEFINE, 0, 0); OCIStmtBindByName(sqlStatement, &tableCol1, errorHandle, (text *)":1", strlen(":1"), (void *)&rowId, sizeof(rowId), SQLT_INT, 0, 0, 0, 0, 0, OCI_DEFAULT); OCIStmtDefineByPos(sqlStatement, &tableCol1, errorHandle, 1, (void *)col1, 256, SQLT_STR, 0, 0, 0, OCI_DEFAULT); OCIStmtDefineByPos(sqlStatement, &tableCol2, errorHandle, 2, (void *)col2, 256, SQLT_STR, 0, 0, 0, OCI_DEFAULT); //这里省略了事务提交、查询结果处理等细节 OCIHandleFree(serviceContext, OCI_HTYPE_SVCCTX); OCIHandleFree(errorHandle, OCI_HTYPE_ERROR); OCIHandleFree(sqlStatement, OCI_HTYPE_STMT); OCIHandleFree(tableCol1, OCI_HTYPE_DEFINE); OCIHandleFree(tableCol2, OCI_HTYPE_DEFINE); OCIHandleFree(environmentHandle, OCI_HTYPE_ENV); return 0; }