将数组从 Java 传递到 Oracle:java.sql.SQLException:无法转换为内部表示:错误 [英] Pass array from Java to Oracle: java.sql.SQLException: Fail to convert to internal representation:error

问题描述

我在 DAO 中有以下内容，当我执行时，我得到 <块引用>

java.sql.SQLException:无法转换为内部表示:test.Project@843

DAO 代码

List projectList = new LinkedList();public void saveRecord(List project)抛出数据库异常，SQLException {对于(项目项目:项目){插入记录(项目)；}}private void insertRecord(Project project) 抛出 SQLException {projectList.add(project);尝试{ArrayDescriptor desc =ArrayDescriptor.createDescriptor("MY_ARRAY", dbConn);//在这一行执行ARRAY arr = new ARRAY(desc, dbConn, (Object[])projectList.toArray());

我该如何解决这个问题?

编辑 1

CREATE OR REPLACE TYPE project_type as object(proj_id varchar2 (10),proj_title varchar2 (10));创建或替换类型 my_array 作为 project_type 的表；

解决方案

不幸的是，这比人们想象的要复杂.您必须使用STRUCT 对象、描述符，最后使用ARRAY.下面是一个工作示例.

-- 数据库代码--创建表 project_types (proj_id VARCHAR2(10),proj_title VARCHAR2(10));/创建或替换类型 project_type AS OBJECT (proj_id VARCHAR2(10),proj_title VARCHAR2(10));/创建或替换类型 my_array 作为 project_type 表；/创建或替换程序 add_projects(p_projects_array IN my_array)作为开始如果 p_projects_array 不是 NULL THENFOR v_i IN 1..p_projects_array.LAST环形INSERT INTO project_types值 (p_projects_array(v_i).proj_id,p_projects_array(v_i).proj_title);结束循环；万一;结尾;/

//Java 代码——主类导入 java.sql.Connection;导入 java.sql.DriverManager;导入 oracle.jdbc.OracleCallableStatement;导入 oracle.jdbc.OracleConnection;导入 oracle.sql.ARRAY;导入 oracle.sql.ArrayDescriptor;导入 oracle.sql.STRUCT;导入 oracle.sql.StructDescriptor;公共类 ArrayExampleMain {public static void main(String[] args) 抛出异常 {OracleConnection conn = getOracleConnection().unwrap(OracleConnection.class);System.out.println("连接成功.");OracleCallableStatement callStmt = null;尝试 {callStmt = (OracleCallableStatement)conn.prepareCall("{call add_projects(?)}");//为 ProjectType 对象的属性创建保存值的数组Object[] project1 = new Object[] {"1", "Title 1"};Object[] project2 = new Object[] {"2", "Title 2"};//数据库中定义的 OBJECT 类型的描述符StructDescriptor projectTypeDesc = StructDescriptor.createDescriptor("PROJECT_TYPE", conn);//每个结构体都是一个 ProjectType 对象STRUCT structProject1 = new STRUCT(projectTypeDesc, conn, project1);STRUCT structProject2 = new STRUCT(projectTypeDesc, conn, project2);结构[] structArrayOfProjects = {structProject1, structProject2};//数据库中定义的 TABLE 类型的描述符ArrayDescriptor projectTypeArrayDesc = ArrayDescriptor.createDescriptor("MY_ARRAY", conn);//包含两个 ProjectType 对象的数组ARRAY arrayOfProjects = new ARRAY(projectTypeArrayDesc, conn, structArrayOfProjects);callStmt.setARRAY(1, arrayOfProjects);callStmt.execute();conn.commit();System.out.println("已提交.");} 捕获(异常 e){if (conn != null) try { conn.rollback();} catch (Exception ex) { System.out.println("回滚失败.");}扔e;} 最后 {callStmt.close();连接.关闭()；}}公共静态连接 getOracleConnection() 抛出异常 {String driver = "oracle.jdbc.driver.OracleDriver";String url = "jdbc:oracle:thin:@YOUR_HOST:orcl";字符串用户名 = "hr";String password = "密码";Class.forName(驱动程序)；//加载 Oracle 驱动Connection conn = DriverManager.getConnection(url, username, password);返回连接；}}

主类执行后检查project_types表的内容:

SELECT * FROM project_types;

输出:

PROJ_ID PROJ_TITLE---------- ----------1 标题 12 标题 2

I have the following in DAO and when I execute, I am getting

java.sql.SQLException: Fail to convert to internal representation: test.Project@843

DAO Code

List projectList = new LinkedList();

public void saveRecord(List<Project> project) 
                       throws DatabaseException,SQLException {

    for (Project items: project) {
        insertRecord(items);
    }
}

private void insertRecord(Project project) throws SQLException {
    projectList.add(project);
    try{
        ArrayDescriptor desc = 
                ArrayDescriptor.createDescriptor("MY_ARRAY", dbConn);

        // execpetion in this line
        ARRAY arr = new ARRAY(desc, dbConn, (Object[])projectList.toArray());

How can I resolve this issue?

Edit 1

CREATE OR REPLACE TYPE project_type as object( 
proj_id varchar2 (10),
proj_title varchar2 (10));


create or replace  type my_array as Table of project_type;

解决方案

Unfortunately, this is more complicated than one might expect. You have to use STRUCT objects, descriptors and, finally, ARRAY. Below is a working example.

-- Database code --

CREATE TABLE project_types (
  proj_id VARCHAR2(10),
  proj_title VARCHAR2(10)
);
/

CREATE OR REPLACE TYPE project_type AS OBJECT ( 
  proj_id VARCHAR2(10),
  proj_title VARCHAR2(10)
);
/

CREATE OR REPLACE TYPE my_array AS TABLE OF project_type;
/

CREATE OR REPLACE PROCEDURE add_projects(p_projects_array IN my_array)
AS
BEGIN
  IF p_projects_array IS NOT NULL THEN
    FOR v_i IN 1..p_projects_array.LAST
    LOOP
      INSERT INTO project_types
        VALUES (p_projects_array(v_i).proj_id,
                p_projects_array(v_i).proj_title);
    END LOOP;
  END IF;
END;
/

// Java code - main class

import java.sql.Connection;
import java.sql.DriverManager;

import oracle.jdbc.OracleCallableStatement;
import oracle.jdbc.OracleConnection;
import oracle.sql.ARRAY;
import oracle.sql.ArrayDescriptor;
import oracle.sql.STRUCT;
import oracle.sql.StructDescriptor;

public class ArrayExampleMain {

  public static void main(String[] args) throws Exception {
    OracleConnection conn = getOracleConnection().unwrap(OracleConnection.class);
    System.out.println("Got Connection.");

    OracleCallableStatement callStmt = null;

    try {
      callStmt = (OracleCallableStatement)conn.prepareCall("{call add_projects(?)}");

      // create array holding values for ProjectType object's properties
      Object[] project1 = new Object[] {"1", "Title 1"};
      Object[] project2 = new Object[] {"2", "Title 2"};

      // descriptor for OBJECT type defined in database
      StructDescriptor projectTypeDesc = StructDescriptor.createDescriptor("PROJECT_TYPE", conn);

      // each struct is one ProjectType object
      STRUCT structProject1 = new STRUCT(projectTypeDesc, conn, project1);
      STRUCT structProject2 = new STRUCT(projectTypeDesc, conn, project2);

      STRUCT[] structArrayOfProjects = {structProject1, structProject2};

      // descriptor of TABLE type defined in database
      ArrayDescriptor projectTypeArrayDesc = ArrayDescriptor.createDescriptor("MY_ARRAY", conn);

      // array holding two ProjectType objects
      ARRAY arrayOfProjects = new ARRAY(projectTypeArrayDesc, conn, structArrayOfProjects);

      callStmt.setARRAY(1, arrayOfProjects); 
      callStmt.execute();
      conn.commit();

      System.out.println("Committed.");
    } catch (Exception e) {
      if (conn != null) try { conn.rollback(); } catch (Exception ex) { System.out.println("Rollback failed."); }
      throw e;
    } finally {
      callStmt.close();
      conn.close();
     }
  }

  public static Connection getOracleConnection() throws Exception {
    String driver = "oracle.jdbc.driver.OracleDriver";
    String url = "jdbc:oracle:thin:@YOUR_HOST:orcl";
    String username = "hr";
    String password = "password";

    Class.forName(driver); // load Oracle driver

    Connection conn = DriverManager.getConnection(url, username, password);

    return conn;
  }
}

Checking content of the project_types table after execution of main class:

SELECT * FROM project_types;

Output:

PROJ_ID    PROJ_TITLE
---------- ----------
1          Title 1    
2          Title 2

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