数据从oracle转换到mysql

时间：2023-12-17 21:14:08

因为项目变更,需要把数据从oracle里转到mysql里。





第一个想法,自己写代码。

20分钟后,算了,还是找找工具吧。





第二步:

下了一个工具,二十分钟后,师兄发现,表的结构是倒完了,但是有的表数据全部倒好了,有的表数据只倒了一半。

算了,换个思路吧。





第三步:

A

算了,自己动手丰衣足食,在第二步已经有mysql表结构的基础上,数据通过代码来倒吧。

自己使用的是原生的jdbc,写了10分钟,看到满篇的Statement,ResultSet,算了,再换个思路吧。

B

我借用了spring的jdbctemplate。spring的xml如下:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
   	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   	xmlns:p="http://www.springframework.org/schema/p"
	xmlns:aop="http://www.springframework.org/schema/aop"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:jee="http://www.springframework.org/schema/jee"
	xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
		http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-4.0.xsd
		http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd">  

	<!-- 数据库连接池c3p0配置 -->
	<bean id="dataSourceOracle" class="com.mchange.v2.c3p0.ComboPooledDataSource"
		destroy-method="close">
		<property name="jdbcUrl" value="jdbc:oracle:thin:@10.150.0.888:1521:orcl"></property>
		<property name="driverClass" value="oracle.jdbc.driver.OracleDriver"></property>
		<property name="user" value=""></property>
		<property name="password" value=""></property>
		<property name="maxPoolSize" value="40"></property>
		<property name="minPoolSize" value="1"></property>
		<property name="initialPoolSize" value="1"></property>
		<property name="maxIdleTime" value="20"></property>
	</bean>
	<bean id="jdbcTemplateOracle" class="org.springframework.jdbc.core.JdbcTemplate">
		<property name="dataSource" ref="dataSourceOracle" />
	</bean>

		<!-- 数据库连接池c3p0配置 -->
	<bean id="dataSourceMysql" class="com.mchange.v2.c3p0.ComboPooledDataSource"
		destroy-method="close">
		<property name="jdbcUrl" value="jdbc:mysql://10.150.0.888/cdm2"></property>
		<property name="driverClass" value="com.mysql.jdbc.Driver"></property>
		<property name="user" value=""></property>
		<property name="password" value=""></property>
		<property name="maxPoolSize" value="40"></property>
		<property name="minPoolSize" value="1"></property>
		<property name="initialPoolSize" value="1"></property>
		<property name="maxIdleTime" value="20"></property>
	</bean>
	<bean id="jdbcTemplateMysql" class="org.springframework.jdbc.core.JdbcTemplate">
		<property name="dataSource" ref="dataSourceMysql" />
	</bean>
</beans>

下面的源代码

package db;

import java.sql.Timestamp;
import java.util.List;
import java.util.Map;

import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.jdbc.core.JdbcTemplate;

public class DBTransfer {
	public static void main(String[] args) {
		ClassPathXmlApplicationContext factory = new ClassPathXmlApplicationContext(
				"applicationContext2.xml");
		JdbcTemplate jdbcTemplateOracle = (JdbcTemplate) factory
				.getBean("jdbcTemplateOracle");
		JdbcTemplate jdbcTemplateMysql = (JdbcTemplate) factory
				.getBean("jdbcTemplateMysql");
		List<Map<String, Object>> tableNames = jdbcTemplateOracle
				.queryForList("select table_name from user_tables");
		for (Map<String, Object> map : tableNames) {
			String tableName = (String) map.get("table_name");   //开始转换一张新的表
			System.out.println("正在转换:" + tableName);
			List<Map<String, Object>> datas = jdbcTemplateOracle
					.queryForList("select * from " + tableName);
			List<Map<String, Object>> columnNames = jdbcTemplateOracle
					.queryForList("SELECT COLUMN_NAME,DATA_TYPE FROM SYS.All_Tab_Columns tc "
							+ " where tc.TABLE_NAME='" + tableName + "' ");
			StringBuilder prefix = null;                //每张表的前缀都是一样的 第一次统一获取
			prefix = new StringBuilder();
			prefix.append("insert into " + tableName + " ( ");
			for (Map<String, Object> column : columnNames) {
				prefix.append(column.get("COLUMN_NAME"));
				prefix.append(",");
			}

			prefix = new StringBuilder(prefix.substring(0, prefix.length() - 1));
			prefix.append(")");
			StringBuilder sb = null;
			for (Map<String, Object> data : datas) {    //处理表中的每一行数据

				sb = new StringBuilder(prefix);   //把之前的前缀拿过来
				sb.append(" values( ");
				String columnName = "";
				for (Map<String, Object> column : columnNames) {
					columnName = (String) column.get("COLUMN_NAME");
					if (data.get(columnName)!=null) {    //

						//处理各种类型的数据
						if (column.get("DATA_TYPE").equals("VARCHAR2")) {
							sb.append("'" + data.get(columnName) + "'");
						}
						if (column.get("DATA_TYPE").equals("NUMBER")) {
							sb.append(data.get(columnName));
						}
						if (column.get("DATA_TYPE").equals("DATE")) {
							Timestamp dateStr=(Timestamp) data.get(columnName);
							sb.append("'" + dateStr + "'");
						}

					}else {
						sb.append("null");
					}

					sb.append(",");
				}
				sb = new StringBuilder(sb.substring(0, sb.length() - 1));
				sb.append(")");

				jdbcTemplateMysql.update(sb.toString());
			}

		}

	}
}

我们项目里,之前的oracle里存的数据格式都很简单,也没有复杂的函数,上面的代码已经够用了,如果大家在使用的时候,出了bug,就再修改吧。

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