数据库查询所有表和字段

查询所有表和字段

介绍

有时候可能要展示所有的表以及所有的字段，下面介绍oracle和mysql的方法以及代码

oracle

sql

查询所有表
select Table_NAME from all_tables where owner = '表空间'
查询字段
SELECT * FROM user_tab_columns where table_name = upper('表名');

代码

    @Testpublic void test1() throws IOException {DruidDataSource dataSource = new DruidDataSource();dataSource.setDriverClassName("oracle.jdbc.driver.OracleDriver");dataSource.setUrl("jdbc:oracle:thin:@127.0.0.1/orcl");dataSource.setUsername("admin");dataSource.setPassword("123456");dataSource.setMaxActive(1);dataSource.setInitialSize(1);dataSource.setMinIdle(1);dataSource.setMaxWait(10000l);dataSource.setConnectionErrorRetryAttempts(0);dataSource.setBreakAfterAcquireFailure(true);JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);List<Map<String, Object>> list = jdbcTemplate.queryForList("select Table_NAME from all_tables where owner = 'admin'");Map<String, List<String>> map = new HashMap<>();list.forEach(e -> {String tableName = String.valueOf(e.get("TABLE_NAME"));List<String> _list = search(jdbcTemplate, tableName);if(!_list.isEmpty()){map.put(tableName,_list);}});StringBuilder builder = new StringBuilder();map.forEach((k,v)->{builder.append("表：\n").append(k).append("\n").append("字段:\n").append(v).append("\n");});FileOutputStream out = new FileOutputStream("表和字段.txt");out.write(builder.toString().getBytes(StandardCharsets.UTF_8));out.flush();out.close();}public List<String> search(JdbcTemplate jdbcTemplate, String tableName) {StringBuilder builder = new StringBuilder().append("SELECT column_name FROM user_tab_columns where table_name = upper('").append(tableName).append("')");List<Map<String, Object>> list = jdbcTemplate.queryForList(builder.toString());return list.stream().map(e -> String.valueOf(e.get("COLUMN_NAME"))).collect(Collectors.toList());}

mysql

sql

-- 查询所有表
SELECT * 
FROMinformation_schema.TABLES 
where TABLE_NAME = '表名';-- 查询所有字段
SELECT*
FROMinformation_schema.COLUMNS
WHEREtable_schema = '库名'AND table_name = '表名'

代码

    @Testpublic void test2() throws IOException {DruidDataSource dataSource = new DruidDataSource();dataSource.setDriverClassName("com.mysql.jdbc.Driver");dataSource.setUrl("jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=GMT%2B8");dataSource.setUsername("root");dataSource.setPassword("123456");dataSource.setMaxActive(1);dataSource.setInitialSize(1);dataSource.setMinIdle(1);dataSource.setMaxWait(10000l);dataSource.setConnectionErrorRetryAttempts(0);dataSource.setBreakAfterAcquireFailure(true);JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);List<Map<String, Object>> list = jdbcTemplate.queryForList("SELECT TABLE_NAME FROM information_schema.TABLES where TABLE_SCHEMA = '库名'");Map<String, List<String>> map = new HashMap<>();list.forEach(e -> {String tableName = String.valueOf(e.get("TABLE_NAME"));List<String> _list = searchMysql(jdbcTemplate, tableName);if (!_list.isEmpty()) {map.put(tableName, _list);}});StringBuilder builder = new StringBuilder();map.forEach((k, v) -> {builder.append("表：\n").append(k).append("\n").append("字段:\n").append(v).append("\n");});FileOutputStream out = new FileOutputStream("表和字段.txt");out.write(builder.toString().getBytes(StandardCharsets.UTF_8));out.flush();out.close();}public List<String> searchMysql(JdbcTemplate jdbcTemplate, String tableName) {StringBuilder builder = new StringBuilder().append("SELECT COLUMN_NAME FROM information_schema.COLUMNS WHERE table_schema = '库名' AND table_name = '").append(tableName).append("'");List<Map<String, Object>> list = jdbcTemplate.queryForList(builder.toString());return list.stream().map(e -> String.valueOf(e.get("COLUMN_NAME"))).collect(Collectors.toList());}