开发过程中一般是一开发数据库 一生产数据库。
有时候在开发数据库中加了数据库字段之后忘记在生产数据库加字段。
写了工具类，用于比较两个数据库的区别。类似工具Navicat也有这样的功能。
支持自动组装Alter语句追加字段。
Oracle版本：
package dbcom;
import java.math.BigDecimal;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* Oracle 数据库比较
* @author Eric zhou
* @since 2013-2-28
*/
public class OracleComparator {
public static String url1 = "jdbc:oracle:thin:@localhost:1521:SIP";
public static String url2 = "jdbc:oracle:thin:@localhost:1521:SIP";
public static String USERNAME = "admin";
public static String PASSWORD = "root";
public static boolean auto_syn = true;//自动同步表结构,true 时启用
public static void main(String[] args) throws Exception{
OracleComparator com = new OracleComparator();
Connection con1 = com.getConnection(url1,USERNAME,PASSWORD);
Connection con2 = com.getConnection(url2,USERNAME,PASSWORD);
System.out.println("已连接到两个数据库...将以数据库1为主数据库进行比较");
String sql = "select TABLE_NAME from USER_TABLES";
List list1 = com.Rs2List(com.getRsBySQL(sql, con1));
List list2 = com.Rs2List(com.getRsBySQL(sql, con2));
com.compare(list1, list2,con1,con2);
System.out.println("比较完成....");
}
private void compare(List list1,List list2,Connection con1,Connection con2) throws Exception {
for (Iterator iterator = list1.iterator(); iterator.hasNext();) {
String name = (String) iterator.next();
if(list2.contains(name)){
this.TableCompare(name, con1, con2);
}else{
if(name.indexOf("$")==-1){
System.out.println("数据库2中，缺少表:"+name);
if(auto_syn){
System.out.print("----------------自动创建表"+name+"...");
System.out.println(createTable(name,con1,con2));
}
}
}
}
}
private void TableCompare(String name,Connection con1,Connection con2) throws Exception {
String sql = "select COLUMN_NAME,DATA_TYPE from USER_TAB_COLUMNS where TABLE_NAME=‘"+name+"‘ ";
Map<String,String> map1 = this.parseColumnList(this.getRsBySQL(sql, con1));
Map<String,String> map2 = this.parseColumnList(this.getRsBySQL(sql, con2));
Set set = map1.keySet();
for (Iterator iterator = set.iterator(); iterator.hasNext();) {
String cname = (String) iterator.next();
if(map2.containsKey(cname)){
if(!map2.get(cname).equals(map1.get(cname))){
System.out.println("数据库2的 "+name+" 表中的字段:"+cname+" 与数据库1中数据类型不一致");
if(auto_syn){
System.out.println("----------------此项目请手动修改!");
}
}
}else{
System.out.println("数据库2的 "+name+" 表中，缺少字段:"+cname);
if(auto_syn){
System.out.print("----------------自动添加字段"+cname+"...");
System.out.println(appendColumn(name,cname,con1,con2));
}
}
}
}
private Map parseColumnList(ResultSet rs1) throws Exception {
Map map = new HashMap();
while(rs1.next()){
map.put(rs1.getString("COLUMN_NAME"), rs1.getString("DATA_TYPE"));
}
return map;
}
private List Rs2List(ResultSet rs1)throws Exception{
List list = new ArrayList();
while(rs1.next()){
list.add(rs1.getString("TABLE_NAME"));
}
return list;
}
private ResultSet getRsBySQL(String sql,Connection con1)throws Exception{
Statement stmt = con1.createStatement();
return stmt.executeQuery(sql);
}
public static String DRIVER = "oracle.jdbc.driver.OracleDriver";
static {
try {
Class.forName(DRIVER).newInstance();
} catch (Exception e) {
e.printStackTrace();
}
}
private Connection getConnection(String url,String username,String password){
try {
return DriverManager.getConnection(url,username,password);
} catch (SQLException e) {
e.printStackTrace();
}
return null;
}
private String createTable(String name,Connection con1,Connection con2){
try {
String sql = "select dbms_metadata.get_ddl(‘TABLE‘,‘"+name+"‘) as XQL from dual";
Statement stmt = con1.createStatement();
ResultSet rs = stmt.executeQuery(sql);
if(rs.next()){
String ddl = rs.getString("XQL");
Statement stmt2 = con2.createStatement();
stmt2.execute(ddl);
return "success";
}else{
return "fail";
}
} catch (SQLException e) {
return "fail";
}
}
private String appendColumn(String name,String colname,Connection con1,Connection con2){
try {
String sql = "select DATA_TYPE,DATA_LENGTH from USER_TAB_COLUMNS where TABLE_NAME=‘"+name+"‘ and COLUMN_NAME=‘"+colname+"‘";
Statement stmt = con1.createStatement();
ResultSet rs = stmt.executeQuery(sql);
if(rs.next()){
String type = rs.getString("DATA_TYPE");
BigDecimal b = rs.getBigDecimal("DATA_LENGTH");
String sql2 = null;
if(type.contains("CLOB")){
sql2 = "alter table "+name+" add ( \""+colname+"\" "+type+" NULL )";
}else{
sql2 = "alter table "+name+" add ( \""+colname+"\" "+type+"("+b.intValue()+") NULL )";
}
Statement stmt2 = con2.createStatement();
stmt2.execute(sql2);
return "success";
}else{
return "fail";
}
} catch (SQLException e) {
e.printStackTrace();
return "fail";
}
}
}
?SQLServer版本
?
package dbcom;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* SQL Server 数据库区别比较
* @author Eric zhou
* @since 2013-2-28
*/
public class SqlServerComparator {
public static String url1 = "jdbc:sqlserver://localhost:1433;DatabaseName=xx1";
public static String url2 = "jdbc:sqlserver://localhost:1433;DatabaseName=xx1";
public static String USERNAME = "sa";
public static String PASSWORD = "123";
public static void main(String[] args) throws Exception{
SqlServerComparator com = new SqlServerComparator();
Connection con1 = com.getConnection(url1,USERNAME,PASSWORD);
Connection con2 = com.getConnection(url2,USERNAME,PASSWORD);
System.out.println("已连接到两个数据库...将以数据库1为主数据库进行比较");
String sql = "select name from sys.all_objects where type_desc=‘USER_TABLE‘";
List list1 = com.Rs2List(com.getRsBySQL(sql, con1));
List list2 = com.Rs2List(com.getRsBySQL(sql, con2));
com.compare(list1, list2,con1,con2);
System.out.println("比较完成....");
}
private void compare(List list1,List list2,Connection con1,Connection con2) throws Exception {
for (Iterator iterator = list1.iterator(); iterator.hasNext();) {
String name = (String) iterator.next();
if(list2.contains(name)){
this.TableCompare(name, con1, con2);
}else{
System.out.println("数据库2中，缺少表:"+name);
}
}
}
private void TableCompare(String name,Connection con1,Connection con2) throws Exception {
String sql = "select c.name,c.system_type_id from sys.all_columns c left join sys.all_objects o on c.object_id=o.object_id where o.name=‘"+name+"‘ ";
Map<String,Integer> map1 = this.parseColumnList(this.getRsBySQL(sql, con1));
Map<String,Integer> map2 = this.parseColumnList(this.getRsBySQL(sql, con2));
Set set = map1.keySet();
for (Iterator iterator = set.iterator(); iterator.hasNext();) {
String cname = (String) iterator.next();
if(map2.containsKey(cname)){
if(map2.get(cname).intValue()!=map1.get(cname).intValue()){
System.out.println("数据库2的 "+name+" 表中的字段:"+cname+" 与数据库1中数据类型不一致");
}
}else{
System.out.println("数据库2的 "+name+" 表中，缺少字段:"+cname);
}
}
}
private Map parseColumnList(ResultSet rs1) throws Exception {
Map map = new HashMap();
while(rs1.next()){
map.put(rs1.getString("name"), rs1.getInt("system_type_id"));
}
return map;
}
private List Rs2List(ResultSet rs1)throws Exception{
List list = new ArrayList();
while(rs1.next()){
list.add(rs1.getString("name"));
}
return list;
}
private ResultSet getRsBySQL(String sql,Connection con1)throws Exception{
Statement stmt = con1.createStatement();
return stmt.executeQuery(sql);
}
public static String DRIVER = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
static {
try {
Class.forName(DRIVER).newInstance();
} catch (Exception e) {
e.printStackTrace();
}
}
private Connection getConnection(String url,String username,String password){
try {
return DriverManager.getConnection(url,username,password);
} catch (SQLException e) {
e.printStackTrace();
}
return null;
}
}
?
Java比较两个数据库中所有表的区别【支持Oracle和SQLServer】
原文：http://namezhou.iteye.com/blog/2164482