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java类实现导出各种数据库insert语句

程序员文章站 2022-03-17 08:58:37
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import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Types;
import java.util.ArrayList;
import java.util.List;

public class Test {
	private static Connection conn=null;
	private static Statement sm = null;
	private static String schema="FJSTL";//模式名
	private static String select="SELECT * FROM";//查询sql
	private static String insert="INSERT INTO";//插入sql
	private static String values="VALUES";//values关键字
	private static String []table={"T_USER"};//table数组
	private static List<String> insertList=new ArrayList<String>();//全局存放insertsql文件的数据
	private static String filePath="E://insertSQL.txt";//绝对路径 导出数据的文件
	/**
	 * 导出数据库表
	 * @param args
	 * @throws SQLException 
	 */
	public static void main(String[] args) throws SQLException {
		List<String> listSQL=new ArrayList<String>();
		connectSQL("oracle.jdbc.driver.OracleDriver", "xxx.xxx.xxx", "xxx", "xxx");//连接数据库
		listSQL=createSQL();//创建查询语句
		executeSQL(conn,sm,listSQL);//执行sql并拼装
		createFile();//创建文件
	}
	/**
	 * 创建insertsql.txt并导出数据
	 */
	private static void createFile() {
		File file=new File(filePath);
		if(!file.exists()){
			try {
				file.createNewFile();
			} catch (IOException e) {
				System.out.println("创建文件名失败!!");
				e.printStackTrace();
			}
		}
		FileWriter fw=null;
		BufferedWriter bw=null;
		try {
			fw = new FileWriter(file);
			bw = new BufferedWriter(fw);
			if(insertList.size()>0){
				for(int i=0;i<insertList.size();i++){
					bw.append(insertList.get(i));
					bw.append("\n");
				}
			}
		} catch (IOException e) {
			e.printStackTrace();
		}finally{
			try {
				bw.close();
				fw.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
	/**
	 * 拼装查询语句
	 * @return 返回select集合
	 */
	private static List<String> createSQL() {
		List<String> listSQL=new ArrayList<String>();
		for(int i=0;i<table.length;i++){
			StringBuffer sb=new StringBuffer();
			sb.append(select).append(" ").append(schema).append(".").append(table[i]);
			listSQL.add(sb.toString());
		}
		return listSQL;
	}
	/**
	 * 连接数据库 创建statement对象
	 * @param driver
	 * @param url
	 * @param UserName
	 * @param Password
	 */
	public static void connectSQL(String driver,String url,String UserName,String Password){
		try{
			Class.forName(driver).newInstance();
			conn = DriverManager.getConnection(url, UserName, Password);
			sm=conn.createStatement();
		}catch(Exception e){
			e.printStackTrace();
		}
	}
	/**
	 * 执行sql并返回插入sql
	 * @param conn
	 * @param sm
	 * @param listSQL
	 * @throws SQLException
	 */
	public static void executeSQL(Connection conn,Statement sm,List listSQL) throws SQLException{
		List<String> insertSQL=new ArrayList<String>();
		ResultSet rs=null;
		try {
			rs = getColumnNameAndColumeValue(sm, listSQL, rs);
		} catch (SQLException e) {
			e.printStackTrace();
		}finally{
			 rs.close();   
			 sm.close();   
			 conn.close();
		}
	}
	/**
	 * 获取列名和列值
	 * @param sm
	 * @param listSQL
	 * @param rs
	 * @return
	 * @throws SQLException
	 */
	private static ResultSet getColumnNameAndColumeValue(Statement sm,
			List listSQL, ResultSet rs) throws SQLException {
		if(listSQL.size()>0){
			for(int j=0;j<listSQL.size();j++){
				String sql=String.valueOf(listSQL.get(j));
				rs=sm.executeQuery(sql);
				ResultSetMetaData rsmd = rs.getMetaData();   
			    int columnCount = rsmd.getColumnCount();  
				while(rs.next()){
					StringBuffer ColumnName=new StringBuffer();
					StringBuffer ColumnValue=new StringBuffer();
					for(int i=1;i<=columnCount;i++){
						String value=rs.getString(i).trim();
						if("".equals(value)){
							value=" ";
						}
						if(i==1||i==columnCount){
							ColumnName.append(rsmd.getColumnName(i));
							if(Types.CHAR == rsmd.getColumnType(i) || Types.VARCHAR == rsmd.getColumnType(i)
									|| Types.LONGVARCHAR == rsmd.getColumnType(i)){
								ColumnValue.append("'").append(value).append("',");
							}else if(Types.SMALLINT == rsmd.getColumnType(i) || Types.INTEGER == rsmd.getColumnType(i)
									|| Types.BIGINT == rsmd.getColumnType(i) || Types.FLOAT == rsmd.getColumnType(i)
									|| Types.DOUBLE == rsmd.getColumnType(i) || Types.NUMERIC == rsmd.getColumnType(i)
									|| Types.DECIMAL == rsmd.getColumnType(i)){
								ColumnValue.append(value).append(",");
							}else if(Types.DATE == rsmd.getColumnType(i) || Types.TIME == rsmd.getColumnType(i)
									|| Types.TIMESTAMP == rsmd.getColumnType(i)){
								ColumnValue.append("timestamp'").append(value).append("',");
							}else{
								ColumnValue.append(value).append(",");
							}
						}else{
							ColumnName.append(","+rsmd.getColumnName(i));
							if(Types.CHAR == rsmd.getColumnType(i) || Types.VARCHAR == rsmd.getColumnType(i)
									|| Types.LONGVARCHAR == rsmd.getColumnType(i)){
								ColumnValue.append("'").append(value).append("'").append(",");
							}else if(Types.SMALLINT == rsmd.getColumnType(i) || Types.INTEGER == rsmd.getColumnType(i)
									|| Types.BIGINT == rsmd.getColumnType(i) || Types.FLOAT == rsmd.getColumnType(i)
									|| Types.DOUBLE == rsmd.getColumnType(i) || Types.NUMERIC == rsmd.getColumnType(i)
									|| Types.DECIMAL == rsmd.getColumnType(i)){
								ColumnValue.append(value).append(",");
							}else if(Types.DATE == rsmd.getColumnType(i) || Types.TIME == rsmd.getColumnType(i)
									|| Types.TIMESTAMP == rsmd.getColumnType(i)){
								ColumnValue.append("timestamp'").append(value).append("',");
							}else{
								ColumnValue.append(value).append(",");
							}
						}
				    }
					System.out.println(ColumnName.toString());
					System.out.println(ColumnValue.toString());
					insertSQL(ColumnName, ColumnValue);
				}
			}
		}
		return rs;
	}
	/**
	 * 拼装insertsql 放到全局list里面
	 * @param ColumnName
	 * @param ColumnValue
	 */
	private static void insertSQL(StringBuffer ColumnName,
			StringBuffer ColumnValue) {
		for(int i=0;i<table.length;i++){
			StringBuffer insertSQL=new StringBuffer();
			insertSQL.append(insert).append(" ").append(schema).append(".")
			.append(table[i]).append("(").append(ColumnName.toString())
			.append(")").append(values).append("(").append(ColumnValue.toString()).append(");");
			insertList.add(insertSQL.toString());
			System.out.println(insertSQL.toString());
		}
	}
}