mysql oci实现 |mysql删除某列数据

要使用MySQL OCI，需要在代码中添加OCI库的引用，并通过OCI的方法来连接MySQL数据库。以下是示例代码：

#include <stdio.h>
#include <oci.h>
#define DBNAME "mydb"
#define DBUSER "myuser"
#define DBPASS "mypassword"
int main(int argc, char **argv)
{
OCIEnv *envhp;
OCIError *errhp;
OCIServer *srvhp;
OCISession *sesshp;
OCIStmt *stmthp;
OCILobLocator *lobhp;
char sql[200];
int status, id;
// 初始化环境
OCIInitialize(OCI_DEFAULT, 0, 0, 0, 0);
// 分配环境句柄
OCIEnvInit(&envhp, OCI_DEFAULT, 0, 0);
// 分配错误句柄
OCIHandleAlloc(envhp, (void **)&errhp, OCI_HTYPE_ERROR, 0, 0);
// 分配服务器句柄
OCIHandleAlloc(envhp, (void **)&srvhp, OCI_HTYPE_SERVER, 0, 0);
// 连接数据库
OCIServerAttach(srvhp, errhp, (text *)DBNAME, strlen(DBNAME), OCI_DEFAULT);
// 分配会话句柄
OCIHandleAlloc(envhp, (void **)&sesshp, OCI_HTYPE_SESSION, 0, 0);
// 开始会话
OCILogon(envhp, errhp, &sesshp, (text *)DBUSER, strlen(DBUSER), (text *)DBPASS, strlen(DBPASS), (text *)DBNAME, strlen(DBNAME));
// 分配语句句柄
OCIHandleAlloc(envhp, (void **)&stmthp, OCI_HTYPE_STMT, 0, 0);
// 执行SQL语句
sprintf(sql, "SELECT id, content FROM mytable WHERE id = %d", id);
OCIStmtPrepare(stmthp, errhp, (text *)sql, strlen(sql), OCI_NTV_SYNTAX, OCI_DEFAULT);
OCIStmtExecute(srvhp, stmthp, errhp, 1, 0, 0, 0, OCI_DEFAULT);
// 分配LOB locator
OCIDescriptorAlloc(envhp, (void **)&lobhp, OCI_DTYPE_LOB, 0, 0);
// 获取LOB字段数据
OCIStmtFetch2(stmthp, errhp, 1, OCI_FETCH_NEXT, OCI_DEFAULT);
// 关闭语句
OCIStmtClose(stmthp, errhp, 0);
// 释放LOB locator
OCIDescriptorFree((void *)lobhp, OCI_DTYPE_LOB);
// 结束会话
OCILogoff(envhp, errhp, sesshp);
// 释放句柄
OCIHandleFree(errhp, OCI_HTYPE_ERROR);
OCIHandleFree(srvhp, OCI_HTYPE_SERVER);
OCIHandleFree(sesshp, OCI_HTYPE_SESSION);
OCIHandleFree(stmthp, OCI_HTYPE_STMT);
// 终止环境
OCIEnvInit(envhp);
return 0;
}

MySQL OCI可以有效提高MySQL数据库的性能，但需要注意的是，OCI是Oracle的专有技术，因此在使用MySQL OCI时需要遵守Oracle的许可协议。