Java DB

Public

// register JDBC Driver
Class.forName(sDrive);
conn = DriverManager.getConnection(sJdbc, sUser, sPasswd);
curr = conn.createStatement();
// execute sql and return result set
rs = curr.executeQuery(sSQL);

rs.getMetaData().getColumnCount();
rs.getMetaData().getColumnName(j)
obj1 = rs.getObject(j);
lcol1.add(obj1 == null?null:obj1.toString());  // ArrayList<String> lcol1 = new ArrayList<>();

rs	getMetaData	getColumnCount	结果集列数量
		getColumnName	列名称
		getColumnType	列数据类型
	getObject		列值

// execute sql and not return, ddl/insert/delete/...
curr.execute(sSQL);

MySQL

// sDrive = "com.mysql.jdbc.Driver";
// MySQL 8.0 以上版本 - JDBC 驱动名及数据库 URL
sDrive = "com.mysql.cj.jdbc.Driver";
sJdbc = "jdbc:mysql://%s:%s/%s?useSSL=false&allowPublicKeyRetrieval=true&serverTimezone=UTC";
String sHost, sPort, sDB, sUser, sPasswd;
sHost = dbinfo.get("host");
sPort = dbinfo.get("port");
sDB = dbinfo.get("db");
sUser = dbinfo.get("user");
sPasswd = dbinfo.get("passwd");