C语言Oracle库构建属于自己的数据库（c oracle库建库）

C语言Oracle库：构建属于自己的数据库

在现代化的信息时代中，数据存储和管理变得越来越重要。很多企业和个人都需要自己的数据库来存储和管理自己的数据。Oracle是一种常用的关系型数据库管理系统，而C语言Oracle库可以让我们在C语言中也能够使用Oracle数据库。以下将介绍如何使用C语言Oracle库来构建属于自己的数据库。

1. 安装Oracle客户端

在使用C语言Oracle库之前，我们需要先安装Oracle客户端。Oracle客户端包含了Oracle提供的一组数据库访问API和一些其他必要的库和支持文件。我们可以从Oracle官网上下载和安装Oracle客户端。

2. 创建新项目

接下来，我们需要在C语言中创建一个新项目。我们可以使用一些常用的集成开发环境（IDE），如Visual Studio或Code::Blocks。在创建新项目时，我们需要选择支持C语言Oracle库的项目类型。

3. 连接到Oracle数据库

在C语言Oracle库中，我们可以使用OCI（Oracle Call Interface）函数来进行连接、查询和管理数据库的操作。我们需要通过OCI函数来连接到Oracle数据库。以下是一个简单的连接Oracle数据库的例子：

“`c

#include

#include

#include

int mn()

{

OCIEnv *envhp;

OCIError *errhp;

OCISvcCtx *svchp;

OCISession *authp;

text *username = (text *)”your_username”;

text *password = (text *)”your_password”;

text *dbname = (text *)”your_database_name”;

sword status;

status = OCIInitialize(OCI_DEFAULT, 0, 0, 0, 0);

OCIHandleAlloc((dvoid *) NULL, (dvoid **) &envhp, OCI_HTYPE_ENV, 0, (dvoid **) 0);

OCIHandleAlloc((dvoid *) envhp, (dvoid **) &errhp, OCI_HTYPE_ERROR, 0, (dvoid **) 0);

OCIHandleAlloc((dvoid *) envhp, (dvoid **) &svchp, OCI_HTYPE_SVCCTX, 0, (dvoid **) 0);

OCIAttrSet((dvoid *) svchp, OCI_HTYPE_SVCCTX, (dvoid *) envhp, (ub4) 0, OCI_ATTR_ENV, (OCIError *) errhp);

status = OCILogon2(envhp, errhp, &svchp, username, strlen((char*) username), password, strlen((char*) password), dbname, strlen((char*) dbname), OCI_DEFAULT);

if(status == OCI_SUCCESS)

{

printf(“Successfully connected to Oracle database!\n”);

OCILogoff(svchp, errhp);

}

else

{

printf(“Fled to connect to Oracle database!\n”);

return 1;

}

OCIHandleFree((dvoid *) envhp, OCI_HTYPE_ENV);

OCIHandleFree((dvoid *) errhp, OCI_HTYPE_ERROR);

OCIHandleFree((dvoid *) svchp, OCI_HTYPE_SVCCTX);

return 0;

}

4. 执行SQL查询

在连接到Oracle数据库之后，我们可以使用OCI函数来执行SQL查询语句。以下是一个简单的查询数据的例子：

```c
#include 
#include 
#include 
 
int mn()
{
    OCIEnv *envhp;
    OCIError *errhp;
    OCISvcCtx *svchp;
    OCISession *authp;
    OCIStmt *stmthp;
    OCIDefine *defnp;
    text *username = (text *)"your_username";
    text *password = (text *)"your_password";
    text *dbname = (text *)"your_database_name";
    sword status;
    oci8_text sqlstmt[] = (oci8_text*)"SELECT * FROM your_table";
 
    status = OCIInitialize(OCI_DEFAULT, 0, 0, 0, 0);
    OCIHandleAlloc((dvoid *) NULL, (dvoid **) &envhp, OCI_HTYPE_ENV, 0, (dvoid **) 0);
    OCIHandleAlloc((dvoid *) envhp, (dvoid **) &errhp, OCI_HTYPE_ERROR, 0, (dvoid **) 0);
    OCIHandleAlloc((dvoid *) envhp, (dvoid **) &svchp, OCI_HTYPE_SVCCTX, 0, (dvoid **) 0);
 
    OCIAttrSet((dvoid *) svchp, OCI_HTYPE_SVCCTX, (dvoid *) envhp, (ub4) 0, OCI_ATTR_ENV, (OCIError *) errhp);
    status = OCILogon2(envhp, errhp, &svchp, username, strlen((char*) username), password, strlen((char*) password), dbname, strlen((char*) dbname), OCI_DEFAULT);
    if(status == OCI_SUCCESS)
    {
        status = OCIHandleAlloc(envhp, (dvoid **)&stmthp, OCI_HTYPE_STMT, 0, (dvoid **)0);
        status = OCIStmtPrepare(stmthp, errhp, sqlstmt, strlen((char*)sqlstmt), OCI_NTV_SYNTAX, OCI_DEFAULT);
        status = OCIStmtExecute(svchp, stmthp, errhp, (ub4) 0, (ub4) 0, (OCISnapshot *) NULL, (OCISnapshot *) NULL, OCI_DEFAULT);
        status = OCIStmtFetch(stmthp, errhp, (ub4) 1, OCI_FETCH_NEXT, OCI_DEFAULT);
        while (status != OCI_NO_DATA)
        {
            /* 处理数据 */
            status = OCIStmtFetch(stmthp, errhp, (ub4) 1, OCI_FETCH_NEXT, OCI_DEFAULT);
        }
        OCIStmtRelease(stmthp, errhp, (OraText *) "INSERT", strlen((char*) "INSERT"), OCI_DEFAULT);
        OCILogoff(svchp, errhp);
    }
    else
    {
        printf("Fled to connect to Oracle database!\n");
        return 1;
    }
 
    OCIHandleFree((dvoid *) envhp, OCI_HTYPE_ENV);
    OCIHandleFree((dvoid *) errhp, OCI_HTYPE_ERROR);
    OCIHandleFree((dvoid *) svchp, OCI_HTYPE_SVCCTX);
 
    return 0;
}

5. 插入、更新和删除数据

除了查询数据之外，我们还可以使用OCI函数来插入、更新和删除数据。以下是一个简单的插入数据的例子：

“`c

#include

#include

#include

int mn()

{

OCIEnv *envhp;

OCIError *errhp;

OCISvcCtx *svchp;

OCISession *authp;

OCIStmt *stmthp;

text *username = (text *)”your_username”;

text *password = (text *)”your_password”;

text *dbname = (text *)”your_database_name”;

sword status;

oci8_text sqlstmt[] = (oci8_text*)”INSERT INTO your_table (id, name) VALUES (1, ‘John’)”;

status = OCIInitialize(OCI_DEFAULT, 0, 0, 0, 0);

OCIHandleAlloc((dvoid *) NULL, (dvoid **) &envhp, OCI_HTYPE_ENV, 0, (dvoid **) 0);

OCIHandleAlloc((dvoid *) envhp, (dvoid **) &errhp, OCI_HTYPE_ERROR, 0, (dvoid **) 0);

OCIHandleAlloc((dvoid *) envhp, (dvoid **) &svchp, OCI_HTYPE_SVCCTX, 0, (dvoid **) 0);

OCIAttrSet((dvoid *) svchp, OCI_HTYPE_SVCCTX, (dvoid *) envhp, (ub4) 0, OCI_ATTR_ENV, (OCIError *) errhp);

status = OCILogon2(envhp, errhp, &svchp, username, strlen((char*) username), password, strlen((char*) password), dbname, strlen((char*) dbname), OCI_DEFAULT);

if(status == OCI_SUCCESS)

{

status = OCIHandleAlloc(envhp, (dvoid **)&stmthp, OCI_HTYPE_STMT, 0, (dvoid **)0);

status = OCIStmtPrepare(stmthp, errhp, sqlstmt, strlen((char*)sqlstmt), OCI_NTV_SYNTAX, OCI_DEFAULT);

status = OCIStmtExecute(svchp, stmthp, errhp, (ub4) 0, (ub4) 0, (OCISnapshot *) NULL, (OCISnapshot *) NULL, OCI_DEFAULT);

OCIStmtRelease(stmthp, errhp, (OraText *) “INSERT”, strlen((char*) “INSERT”), OCI_DEFAULT);

OCILogoff(svchp, errhp);

}

else

{

printf(“