数据库多张表导出到excel

数据库多张表导出到excel

public static void export() throws Exception{

//声明需要导出的数据库

String dbName = "hdcloude";

//声明book

HSSFWorkbook book = new HSSFWorkbook();

//获取Connection,获取db的元数据

//Connection con = DataSourceUtils.getConn();

Connection con =DriverManager.getConnection("jdbc:MySQL://127.0.0.1:3306", "root", "root");

//声明statemen

Statement st = con.createStatement();

//st.execute("use "+dbName);

DatabaseMetaData dmd = con.getMetaData();

//获取数据库有多少表

ResultSet rs = dmd.getTables(dbName,dbName,null,new String[]{"TABLE"});

//获取所有表名　－　就是一个sheet

List<String> tables = new ArrayList<String>();

while(rs.next()){

String tableName = rs.getString("TABLE_NAME");

System.out.println(tableName);

tables.add(tableName);

}

for(String tableName:tables){

HSSFSheet sheet = book.createSheet(tableName);

//声明sql

String sql = "select * from "+dbName+"."+tableName;

//查询数据

rs = st.executeQuery(sql);

//根据查询的结果，分析结果集的元数据

ResultSetMetaData rsmd = rs.getMetaData();

//获取这个查询有多少行

int cols = rsmd.getColumnCount();

//获取所有列名

//创建第一行

HSSFRow row = sheet.createRow(0);

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

String colName = rsmd.getColumnName(i+1);

//创建一个新的列

HSSFCell cell = row.createCell(i);

//写入列名

cell.setCellValue(colName);

}

//遍历数据

int index = 1;

while(rs.next()){

row = sheet.createRow(index++);

//声明列

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

String val = rs.getString(i+1);

//声明列

HSSFCell cel = row.createCell(i);

//放数据

cel.setCellValue(val);

}

}

}

con.close();

book.write(new FileOutputStream("\\"+dbName+".xls"));

}