数据库数据的转换,从一张表转换到另一个表

本文介绍了一种批量处理数据的方法,包括不使用数据库连接池的传统方式和使用数据库连接池的多线程处理方式。通过分页查询和分批插入,有效地提高了数据处理效率。

1、没有使用数据库连接池(主要思想是分页查询、分批插入)

package util;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class BatchProcess {

	public static void batchInsert(int m, int n) {

		long start = System.currentTimeMillis();

		String insertSql = "INSERT INTO LIJING727_ORIGDATA(DATA0,DATA1,"
				+ "DATA2,DATA3,DATA4,DATA5,DATA6,DATA7,DATA8,DATA9) VALUES "
				+ "(?,?,?,?,?,?,?,?,?,?)";

		for (int i = 0; i < m; i++) {

			Connection conn = DbConnStatic.getConnection();

			try {

				PreparedStatement pstmt = conn.prepareStatement(insertSql);

				for (int j = 0; j < n; j++) {

					pstmt.setInt(1, i * n + j + 1);
					pstmt.setString(2, "test" + 2);
					pstmt.setString(3, "test" + 3);
					pstmt.setString(4, "test" + 4);
					pstmt.setString(5, "test" + 5);
					pstmt.setString(6, "test" + 6);
					pstmt.setString(7, "test" + 7);
					pstmt.setString(8, "test" + 8);
					pstmt.setString(9, "test" + 9);
					pstmt.setString(10, "test" + 10);

					pstmt.addBatch();

				}

				pstmt.executeBatch();
				pstmt.close();
				// conn.close();
				// DbConnection.freeConnection();

			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}

		}

		long end = System.currentTimeMillis();

		System.out
				.println("批量插入数据" + m + "*" + n + " 用时" + (end - start) / 1000f);

	}

	public static void deleteAllData() {

		long start = System.currentTimeMillis();

		Connection conn = DbConnStatic.getConnection();

		try {

			Statement stmt = conn.createStatement();

			String sql1 = "DELETE FROM LIJING727_ORIGDATA";
			//String sql2 = "DELETE FROM LIJING727_TEMPDATA";

			stmt.execute(sql1);
			//stmt.execute(sql2);

		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

		long end = System.currentTimeMillis();

		System.out.println("批量删除所有数据 用时" + (end - start) / 1000f);

	}

	public static void transferData(int m, int n) {

		long start = System.currentTimeMillis();

		String insertSql = "INSERT INTO LIJING727_TEMPDATA(DATA0,DATA1,"
				+ "DATA2,DATA3,DATA4,DATA5,DATA6,DATA7,DATA8,DATA9) VALUES "
				+ "(?,?,?,?,?,?,?,?,?,?)";

		String selectSql = "SELECT * FROM (SELECT rownum r,a.* "
				+ "FROM LIJING727_ORIGDATA a WHERE rownum <= ?) WHERE r >= ?";
		
		for (int i = 0; i < m; i++) {

			Connection insertConn = new DbConn().getConnection();
			Connection selectConn = new DbConn().getConnection();

			try {

				PreparedStatement selectPstmt = selectConn.prepareStatement(selectSql);
				PreparedStatement insertPstmt = insertConn.prepareStatement(insertSql);
				
				selectPstmt.setInt(1, (i+1) * n);
				selectPstmt.setInt(2, i * n + 1);
				
				ResultSet rs = selectPstmt.executeQuery();
				
				while (rs.next()) {
					
					insertPstmt.setInt(1, rs.getInt(2));
					insertPstmt.setString(2, rs.getString(3));
					insertPstmt.setString(3, rs.getString(4));
					insertPstmt.setString(4, rs.getString(5));
					insertPstmt.setString(5, rs.getString(6));
					insertPstmt.setString(6, rs.getString(7));
					insertPstmt.setString(7, rs.getString(8));
					insertPstmt.setString(8, rs.getString(9));
					insertPstmt.setString(9, rs.getString(10));
					insertPstmt.setString(10, rs.getString(11));

					insertPstmt.addBatch();
					
				}

				insertPstmt.executeBatch();
				insertPstmt.close();
				selectPstmt.close();


			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}

		}

		long end = System.currentTimeMillis();

		System.out
				.println("批量转换" + m + "*" + n + " 用时" + (end - start) / 1000f);

	}

}

 

 

2、使用数据库连接池

package util;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import oracle.jdbc.driver.OraclePreparedStatement;

public class MultiThreadProcess {

	public static void batchInsert(int m, int n) throws ClassNotFoundException,
			SQLException, InterruptedException {

		ExecutorService exec = Executors.newCachedThreadPool();

		DbPool dbPool = new DbPool();
		dbPool.createPool();

		long start = System.currentTimeMillis();

		for (int i = 0; i < m; i++) {

			exec.execute(new BatchInsertTask(dbPool, i, n, start));

			// Thread thread = new Thread(new BatchInsertTask(dbPool, i, n,
			// start));
			// thread.join(); // 线程挂接,当前线程阻塞,thread执行完后,主线程才能执行
			// exec.execute(thread);
			// thread.start();

		}

		exec.shutdown();

	}

	public static void batchTransfer(int m, int n)
			throws ClassNotFoundException, SQLException, InterruptedException {

		ExecutorService exec = Executors.newCachedThreadPool();

		DbPool dbPool = new DbPool();
		dbPool.createPool();

		long start = System.currentTimeMillis();

		for (int i = 0; i < m; i++) {

			exec.execute(new BatchTransferTask(dbPool, i, n, start));

		}

		exec.shutdown();

	}

}

class BatchInsertTask implements Runnable {

	DbPool dbPool;
	int threadNum = 0;
	int batchNum = 0;
	long start;

	BatchInsertTask(DbPool dbPool, int threadNum, int batchNum, long startTime) {

		this.dbPool = dbPool;
		this.threadNum = threadNum;
		this.batchNum = batchNum;
		start = startTime;
	}

	@Override
	public void run() {

		String insertSql = "INSERT INTO LIJING727_ORIGDATA(DATA0,DATA1,"
				+ "DATA2,DATA3,DATA4,DATA5,DATA6,DATA7,DATA8,DATA9) VALUES "
				+ "(?,?,?,?,?,?,?,?,?,?)";

		try {

			Connection conn = dbPool.getConnection();
			OraclePreparedStatement pstmt = (OraclePreparedStatement) conn
					.prepareStatement(insertSql);

			for (int j = 0; j < batchNum; j++) {

				pstmt.setInt(1, threadNum * batchNum + j + 1);
				pstmt.setString(2, "test" + 2);
				pstmt.setString(3, "test" + 3);
				pstmt.setString(4, "test" + 4);
				pstmt.setString(5, "test" + 5);
				pstmt.setString(6, "test" + 6);
				pstmt.setString(7, "test" + 7);
				pstmt.setString(8, "test" + 8);
				pstmt.setString(9, "test" + 9);
				pstmt.setString(10, "test" + 10);

				pstmt.addBatch();

			}

			pstmt.executeBatch();
			pstmt.close();
			dbPool.returnConnection(conn);

			long end = System.currentTimeMillis();

			System.out.println("批量插入数据用时" + (end - start) / 1000f);

		} catch (SQLException e) {

			e.printStackTrace();

		}

	}

}

class BatchTransferTask implements Runnable {

	DbPool dbPool;
	int threadNum = 0;
	int batchNum = 0;
	long start;

	BatchTransferTask(DbPool dbPool, int threadNum, int batchNum, long startTime) {

		this.dbPool = dbPool;
		this.threadNum = threadNum;
		this.batchNum = batchNum;
		start = startTime;
	}

	@Override
	public void run() {

		String insertSql = "INSERT INTO LIJING727_TEMPDATA(DATA0,DATA1,"
				+ "DATA2,DATA3,DATA4,DATA5,DATA6,DATA7,DATA8,DATA9) VALUES "
				+ "(?,?,?,?,?,?,?,?,?,?)";

		String selectSql = "SELECT b.DATA0,b.DATA1,b.DATA2,b.DATA3,b.DATA4,"
				+ "b.DATA5,b.DATA6,b.DATA7,b.DATA8,b.DATA9"
				+ " FROM (SELECT rownum r,"
				+ "a.DATA0,a.DATA1,a.DATA2,a.DATA3,a.DATA4,a.DATA5,a.DATA6,"
				+ "a.DATA7,a.DATA8,a.DATA9"
				+ " FROM LIJING727_ORIGDATA a WHERE rownum <= ?) b"
				+ " WHERE r >= ?";

		// String selectSql = "SELECT b.DATA0,b.DATA1,b.DATA2,b.DATA3,b.DATA4,"
		// + "b.DATA5,b.DATA6,b.DATA7,b.DATA8,b.DATA9"
		// + " FROM (SELECT rownum r,a.*"
		// + " FROM LIJING727_ORIGDATA a WHERE rownum <= ?) b"
		// + " WHERE r >= ?";

		try {

			Connection insertConn = dbPool.getConnection();
			Connection selectConn = dbPool.getConnection();

			OraclePreparedStatement selectPstmt = (OraclePreparedStatement) selectConn
					.prepareStatement(selectSql);
			OraclePreparedStatement insertPstmt = (OraclePreparedStatement) insertConn
					.prepareStatement(insertSql);

			selectPstmt.setInt(1, (threadNum + 1) * batchNum);
			selectPstmt.setInt(2, threadNum * batchNum + 1);

			ResultSet rs = selectPstmt.executeQuery();

			while (rs.next()) {

				insertPstmt.setInt(1, rs.getInt(1));
				insertPstmt.setString(2, rs.getString(2));
				insertPstmt.setString(3, rs.getString(3));
				insertPstmt.setString(4, rs.getString(4));
				insertPstmt.setString(5, rs.getString(5));
				insertPstmt.setString(6, rs.getString(6));
				insertPstmt.setString(7, rs.getString(7));
				insertPstmt.setString(8, rs.getString(8));
				insertPstmt.setString(9, rs.getString(9));
				insertPstmt.setString(10, rs.getString(10));

				insertPstmt.addBatch();

			}

			rs.close();
			insertPstmt.executeBatch();
			insertPstmt.close();
			selectPstmt.close();

			dbPool.returnConnection(insertConn);
			dbPool.returnConnection(selectConn);

			long end = System.currentTimeMillis();

			System.out.println("批量转换数据用时" + (end - start) / 1000f);

		} catch (SQLException e) {
			e.printStackTrace();
		}

	}

}

 

如果数据量很大,造成JVM溢出,可以在查询时的是分次处理,减少JVM的负担。

package util;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import oracle.jdbc.driver.OraclePreparedStatement;

public class MultiBatchProcess {

	public static void batchInsert(int threadNum, int timeNum, int batchNum)
			throws ClassNotFoundException, SQLException, InterruptedException {

		ExecutorService exec = Executors.newCachedThreadPool();

		DbPool dbPool = new DbPool();
		dbPool.createPool();

		long start = System.currentTimeMillis();

		for (int i = 0; i < threadNum; i++) {

			exec.execute(new BatchInsert(dbPool, i, timeNum, batchNum, start));

		}

		exec.shutdown();

	}

	public static void batchTranfer(int threadNum, int timeNum, int batchNum)
			throws ClassNotFoundException, SQLException, InterruptedException {

		ExecutorService exec = Executors.newCachedThreadPool();

		DbPool dbPool = new DbPool();
		dbPool.createPool();

		long start = System.currentTimeMillis();

		for (int i = 0; i < threadNum; i++) {

			exec
					.execute(new BatchTransfer(dbPool, i, timeNum, batchNum,
							start));

		}

		exec.shutdown();

	}

}

class BatchTransfer implements Runnable {

	DbPool dbPool;
	int threadNo = 0;
	int timeNum = 0;
	int batchNum = 0;
	long start = 0;

	BatchTransfer(DbPool dbPool, int threadNum, int timeNum, int batchnum,
			long start) {

		this.dbPool = dbPool;
		this.threadNo = threadNum;
		this.timeNum = timeNum;
		this.batchNum = batchnum;
		this.start = start;

	}

	@Override
	public void run() {

		String insertSql = "INSERT INTO LIJING727_TEMPDATA(DATA0,DATA1,"
				+ "DATA2,DATA3,DATA4,DATA5,DATA6,DATA7,DATA8,DATA9) VALUES "
				+ "(?,?,?,?,?,?,?,?,?,?)";

		String selectSql = "SELECT b.DATA0,b.DATA1,b.DATA2,b.DATA3,b.DATA4,"
				+ "b.DATA5,b.DATA6,b.DATA7,b.DATA8,b.DATA9"
				+ " FROM (SELECT rownum r,"
				+ "a.DATA0,a.DATA1,a.DATA2,a.DATA3,a.DATA4,a.DATA5,a.DATA6,"
				+ "a.DATA7,a.DATA8,a.DATA9"
				+ " FROM LIJING727_ORIGDATA a WHERE rownum <= ?) b"
				+ " WHERE r >= ?";

		// String selectSql = "SELECT b.DATA0,b.DATA1,b.DATA2,b.DATA3,b.DATA4,"
		// + "b.DATA5,b.DATA6,b.DATA7,b.DATA8,b.DATA9"
		// + " FROM (SELECT rownum r,a.*"
		// + " FROM LIJING727_ORIGDATA a WHERE rownum <= ?) b"
		// + " WHERE r >= ?";

		try {

			Connection insertConn = dbPool.getConnection();
			Connection selectConn = dbPool.getConnection();

			OraclePreparedStatement selectPstmt = (OraclePreparedStatement) selectConn
					.prepareStatement(selectSql);
			OraclePreparedStatement insertPstmt = (OraclePreparedStatement) insertConn
					.prepareStatement(insertSql);

			for (int i = 0; i < timeNum; i++) {

				selectPstmt.setInt(1, threadNo * timeNum * batchNum + (i + 1)
						* batchNum);
				selectPstmt.setInt(2, threadNo * timeNum * batchNum + i
						* batchNum + 1);

				ResultSet rs = selectPstmt.executeQuery();

				while (rs.next()) {

					insertPstmt.setInt(1, rs.getInt(1));
					insertPstmt.setString(2, rs.getString(2));
					insertPstmt.setString(3, rs.getString(3));
					insertPstmt.setString(4, rs.getString(4));
					insertPstmt.setString(5, rs.getString(5));
					insertPstmt.setString(6, rs.getString(6));
					insertPstmt.setString(7, rs.getString(7));
					insertPstmt.setString(8, rs.getString(8));
					insertPstmt.setString(9, rs.getString(9));
					insertPstmt.setString(10, rs.getString(10));

					insertPstmt.addBatch();

				}

				rs.close();
				insertPstmt.executeBatch();
				insertPstmt.clearBatch();

			}

			insertPstmt.close();
			selectPstmt.close();

			dbPool.returnConnection(insertConn);
			dbPool.returnConnection(selectConn);

			long end = System.currentTimeMillis();

			System.out.println("批量转换数据用时" + (end - start) / 1000f);

		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

}

class BatchInsert implements Runnable {

	DbPool dbPool;
	int threadNo = 0;
	int timeNum = 0;
	int batchNum = 0;
	long start = 0;

	BatchInsert(DbPool dbPool, int threadNum, int timeNum, int batchnum,
			long start) {

		this.dbPool = dbPool;
		this.threadNo = threadNum;
		this.timeNum = timeNum;
		this.batchNum = batchnum;
		this.start = start;

	}

	@Override
	public void run() {

		String insertSql = "INSERT INTO LIJING727_ORIGDATA(DATA0,DATA1,"
				+ "DATA2,DATA3,DATA4,DATA5,DATA6,DATA7,DATA8,DATA9) VALUES "
				+ "(?,?,?,?,?,?,?,?,?,?)";

		try {

			Connection conn = dbPool.getConnection();
			OraclePreparedStatement pstmt = (OraclePreparedStatement) conn
					.prepareStatement(insertSql);

			for (int i = 0; i < timeNum; i++) {

				for (int j = 0; j < batchNum; j++) {

					pstmt.setInt(1, threadNo * timeNum * batchNum + i
							* batchNum + j + 1);
					pstmt.setString(2, "test" + 2);
					pstmt.setString(3, "test" + 3);
					pstmt.setString(4, "test" + 4);
					pstmt.setString(5, "test" + 5);
					pstmt.setString(6, "test" + 6);
					pstmt.setString(7, "test" + 7);
					pstmt.setString(8, "test" + 8);
					pstmt.setString(9, "test" + 9);
					pstmt.setString(10, "test" + 10);

					pstmt.addBatch();

				}

				pstmt.executeBatch();
				pstmt.clearBatch();
			}

			pstmt.close();
			dbPool.returnConnection(conn);

			long end = System.currentTimeMillis();

			System.out.println("批量插入数据用时" + (end - start) / 1000f);

		} catch (SQLException e) {

			e.printStackTrace();

		}

	}

}

  

<think>嗯,用户明确提出了需要将Oracle数据库中的一张数据复制到一张的具体需求,并且引用了insertselect语句。看来用户正在处理数据库迁移或数据备份的工作。从引用资料来看,用户已经查阅了多种复制方法,包括全复制、选择性字段复制以及跨数据库复制。但当前问题聚焦在单数据库内的间复制,核心需求是高效安全地完成数据转移。注意到引用2提供了最贴近当前需求的解决方案:1.使用CREATETABLEAS创建新并复制全部数据2.使用INSERTINTOSELECT将数据追加到现有用户特意提到"insertselect",说明目标可能已经存在。需要重点讲解第二种方案的具体实现和注意事项。考虑到用户可能是DBA或开发人员,应该强调几个实用要点:-字段匹配的两种方案(全字段复制和字段映射)-避免主键冲突的处理方式-大复制时的性能优化建议-错误调试技巧需要特别注意引用5提到的跨数据库复制方案虽然存在,但不适用当前场景,这点要明确区分说明。用户的问题描述很专业,说明对SQL有基础了解,可以适当使用术语。但也要准备解释字段映射这样的核心概念,避免用户实际执行时出错。</think> 在 Oracle 数据库中将一张数据复制到一张,使用 `INSERT INTO ... SELECT` 语句是最常用且高效的方法。以下是具体操作方式及注意事项: --- ### 一、复制数据到 **新**(目标不存在) 若需要完全复制源数据 **并创建新**: ```sql CREATE TABLE 新名 AS SELECT * FROM 源名; ``` **示例**(复制 `employees` 到新 `employees_backup`): ```sql CREATE TABLE employees_backup AS SELECT * FROM employees; ``` **特殊场景**: ✅ **仅复制结构(不复制数据)**: ```sql CREATE TABLE 新名 AS SELECT * FROM 源名 WHERE 1=0; ``` --- ### 二、复制数据到 **已存在**(目标已创建) 使用 `INSERT INTO ... SELECT` 语法: ```sql INSERT INTO 目标名 [(列1, 列2, ...)] SELECT 列1, 列2, ... FROM 源名 [WHERE 条件]; ``` #### 1. **全字段复制** ```sql INSERT INTO 目标名 SELECT * FROM 源名; ``` > ⚠️ 要求:目标的 **字段数量、顺序、类型必须完全一致**。 #### 2. **部分字段复制** ```sql INSERT INTO 目标名 (目标列1, 目标列2) SELECT 源列1, 源列2 FROM 源名; ``` **示例**(复制 `employees` 的 `name`, `salary` 到 `backup_table`): ```sql INSERT INTO backup_table (emp_name, emp_salary) SELECT name, salary FROM employees; ``` #### 3. **复制时转换或过滤数据** ```sql INSERT INTO target_table (id, new_name, bonus) SELECT id, UPPER(name), salary * 0.1 FROM employees WHERE salary > 5000; ``` --- ### 三、常见问题解决方案 #### 1. **主键冲突** 若目标存在主键/唯一约束,重复数据会报错 `ORA-00001`。解决方案: ```sql -- 跳过重复数据(仅插入不冲突数据) INSERT /*+ IGNORE_ROW_ON_DUPKEY_INDEX(目标名(主键列)) */ INTO 目标名 SELECT * FROM 源名; ``` #### 2. **字段顺序不一致** 显式指定字段映射: ```sql INSERT INTO 目标 (字段A, 字段B, 字段C) SELECT 源字段C, 源字段A, 源字段B FROM 源; ``` #### 3. **跨数据库复制**(不同Schema) 需添加Schema名: ```sql INSERT INTO schema2.target_table SELECT * FROM schema1.source_table; ``` #### 4. **大性能优化** ```sql INSERT /*+ APPEND */ INTO 目标 -- 使用直接路径插入(需开启事务) SELECT * FROM 源; COMMIT; -- 提交事务 ``` --- ### 四、重要注意事项 1. **事务一致性**:大操作建议手动提交事务(`BEGIN` / `COMMIT`),避免意外中断。 2. **权限检查**:用户需有源的 `SELECT` 权限和目标的 `INSERT` 权限。 3. **LOB字段**:若含 `CLOB/BLOB` 字段,需使用 `DBMS_LOB` 包特殊处理[^2]。 4. **空间预留**:确保目标空间足够,可提前执行 `ALTER TABLE ... ALLOCATE EXTENT`。 ---
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