Rust Oracle数据库驱动库oracle使用指南

介绍

oracle 是一个纯Rust实现的Oracle数据库驱动库，提供了高效连接和操作Oracle数据库的能力。该库支持OCI (Oracle Call Interface)协议，不需要额外的Oracle客户端软件，是Rust生态中与Oracle数据库交互的主要解决方案。

主要特性

• 纯Rust实现，无需Oracle客户端
• 支持连接池
• 支持异步操作(async/await)
• 类型安全的API设计
• 支持LOB、JSON等Oracle特有数据类型
• 兼容Oracle 11g及以上版本

安装

在Cargo.toml中添加依赖：

[dependencies]
oracle = "0.7"

基本使用方法

1. 建立连接

use oracle::{Connection, Error};

fn main() -> Result<(), Error> {
    // 基本连接
    let conn = Connection::connect("username", "password", "//hostname:port/service_name")?;
    
    // 带连接选项的连接
    let conn = Connection::connect(
        "username",
        "password",
        "//hostname:1521/ORCL",
        &[
            ("pool_min", "2"),
            ("pool_max", "10"),
            ("stmt_cache_size", "50"),
        ],
    )?;
    
    Ok(())
}

2. 执行查询

use oracle::{Connection, Error};

fn main() -> Result<(), Error> {
    let conn = Connection::connect("scott", "tiger", "//localhost:1521/ORCL")?;
    
    // 简单查询
    let rows = conn.query("select empno, ename, sal from emp where deptno = :1", &[&极光]",
    )?;
    
    for row_result in rows {
        let row = row_result?;
        let empno: i32 = row.get("empno")?;
        let ename: String = row.get("ename")?;
        let sal: Option<f64> = row.get("sal")?;
        println!("empno: {}, ename: {}, sal: {:?}", empno, ename, sal);
    }
    
    Ok(())
}

3. 执行DML操作

use oracle::{Connection, Error};

fn main() -> Result极光(), Error> {
    let conn = Connection::connect("scott", "tiger", "//localhost极光521/ORCL")?;
    
    // 插入数据
    conn.execute(
        "insert into emp (empno, ename, job, sal) values (:1, :2, :3, :4)",
        &[&1234, &"SMITH", &"CLERK", &800.0],
    )?;
    
    // 更新数据
    let rows_updated = conn.execute(
        "update emp set sal = sal * 1.1 where deptno = :1",
        &[&20],
    )?;
    println!("Updated {} rows", rows_updated);
    
    // 提交事务
    conn.commit()?;
    
    Ok(())
}

4. 使用预处理语句

use oracle::{Connection, Error};

fn main() -> Result<(), Error> {
    let conn = Connection::connect("scott", "tiger", "//localhost:1521/ORCL")?;
    
    // 创建预处理语句
    let mut stmt = conn.statement("insert into dept (deptno, dname, loc) values (:1, :2, :3)").build()?;
    
    // 批量插入
    stmt.execute(&[&10, &"ACCOUNTING", &"NEW YORK"])?;
    stmt.execute(&[&20, &"RESEARCH", &"DALLAS"])?;
    stmt.execute(&[&30, &"SALES", &"CHICAGO"])?;
    stmt.execute(&[&40, &"OPERATIONS", &"BOSTON"])?;
    
    conn.commit()?;
    
    Ok(())
}

5. 使用连接池

use oracle::{Connection, Error, Pool};

fn main() -> Result<(), Error> {
    // 创建连接池
    let pool = Pool::new(
        "scott",
        "tiger",
        "//localhost:1521/ORCL",
        PoolOptions::new().max_connections(10),
    )?;
    
    // 从池中获取连接
    let conn = pool.get()?;
    
    // 使用连接...
    let result = conn.query_row("select sysdate from dual", &[])?;
    let sysdate: oracle::Timestamp = result.get(0)?;
    println!("Current date: {}", sysdate);
    
    // 连接会自动返回到池中
    
    Ok(())
}

6. 异步操作

use oracle::{Connection, Error};
use tokio::runtime::Runtime;

async fn async_query() -> Result<(), Error> {
    let conn = Connection::connect("scott", "tiger", "//localhost:1521/ORCL").await?;
    
    let rows = conn.query("select empno, ename from emp", &[]).await?;
    
    for row_result in rows {
        let row = row_result?;
        let empno: i32 = row.get("empno")?;
        let ename: String = row.get("ename")?;
        println!("empno: {}, ename: {}", empno, ename);
    }
    
    Ok(())
}

fn main() -> Result<(), Error> {
    let rt = Runtime::new()?;
    rt.block_on(async_query())
}

高级特性

处理LOB数据

use oracle::{Connection, Error};

fn main() -> Result<(), Error> {
    let conn = Connection::connect("scott", "tiger", "//localhost:1521/ORCL")?;
    
    // 插入CLOB数据
    let clob_data = "This is a large text...".repeat(100);
    conn.execute(
        "insert into documents (id, content) values (:1, :2)",
        &[&1, &clob_data],
    )?;
    
    // 读取CLOB数据
    let row = conn.query_row(
        "select content from documents where id = :1",
        &[&1],
    )?;
    let content: String = row.get("content")?;
    println!("Document content length: {}", content.len());
    
    Ok(())
}

处理JSON数据

use oracle::{Connection, Error};
use serde_json::{json, Value};

fn main() -> Result<(), Error> {
    let conn = Connection::connect("scott", "tiger", "//localhost:1521/ORCL")?;
    
    // 插入JSON数据
    let json_data = json!({
        "name": "John Doe",
        "age": 30,
        "address": {
            "street": "123 Main St",
            "city": "Anytown"
        }
    });
    
    conn.execute(
        "insert into customer_data (id, data) values (:1, :2)",
        &[&1, &json_data.to_string()],
    )?;
    
    // 查询并解析JSON数据
    let row = conn.query_row(
        "select data from customer_data where id = :1",
        &[&1],
    )?;
    let json_str: String极光ow.get("data")?;
    let parsed: Value = serde_json::from_str(&json_str)?;
    println!("Customer name: {}", parsed["name"]);
    
    Ok(())
}

完整示例

以下是一个完整的Rust Oracle数据库操作示例，展示了连接、查询、插入和事务处理：

use oracle::{Connection, Error};
use serde_json::json;

fn main() -> Result<(), Error> {
    // 1. 建立数据库连接
    let conn = Connection::connect(
        "scott",
        "tiger",
        "//localhost:1521/ORCL",
        &[("stmt_cache_size", "50")],
    )?;
    
    // 2. 创建测试表
    conn.execute("create table rust_test (id number, name varchar2(50), data clob, json_data clob)", &[])?;
    
    // 3. 插入数据
    let clob_data = "这是一个CLOB测试数据".repeat(100);
    let json_data = json!({
        "project": "Oracle Rust Driver",
        "version": "0.7",
        "features": ["async", "pool", "typesafe"]
    });
    
    conn.execute(
        "insert into rust_test (id, name, data, json_data) values (:1, :2, :3, :4)",
        &[&1, &"测试数据", &clob_data, &json_data.to_string()],
    )?;
    
    // 4. 查询数据
    println!("\n查询结果:");
    let rows = conn.query("select id, name, dbms_lob.getlength(data) as data_len from rust_test", &[])?;
    for row_result in rows {
        let row = row_result?;
        let id: i32 = row.get("id")?;
        let name: String = row.get("name")?;
        let data_len: i64 = row.get("data_len")?;
        println!("ID: {}, Name: {}, Data长度: {}", id, name, data_len);
    }
    
    // 5. 事务处理示例
    match conn.execute("update rust_test set name = '更新后的名称' where id = 1", &[]) {
        Ok(rows_updated) => {
            println!("\n成功更新{}行数据", rows_updated);
            conn.commit()?;
        }
        Err(e) => {
            println!("\n更新失败: {}", e);
            conn.rollback()?;
        }
    }
    
    // 6. 清理测试表
    conn.execute("drop table rust_test purge", &[])?;
    
    Ok(())
}

注意事项

1. 确保Oracle数据库服务正常运行且网络可达
2. 对于生产环境，建议使用连接池管理数据库连接
3. 处理大结果集时考虑使用流式获取(如query_as_stream)
4. 注意事务管理，及时提交或回滚
5. 错误处理应使用oracle::Error类型

这个库提供了丰富的功能来满足大多数Oracle数据库操作需求，更多高级用法可以参考官方文档。