一、导入mysql的驱动：“com.mysql.jdbc.Driver”, 必须将mysql的驱动 包（jar文件）导入到本工程中。
Class.forName("com.mysql.jdbc.Driver");
二、由DriverManager驱动的管理类对象去获得Connection，在此之前需要先导入mysql的驱动包（或者驱动类）。
Connection conn = DriverManager.getConnection(url, userName, userPassword);
三、由Connection对象，获得执行增删改的sql语句的状态对象Statement
Statement stmt = conn.createStatement();
四、执行增删改查。
主要代码：
1、获得连接对象
/**
*
* @return：返回获得的连接对象
* @throws SQLException
* @throws ClassNotFoundException
*/
public static Connection getConn(String database, String user,
String password) throws ClassNotFoundException
{
Class.forName("com.mysql.jdbc.Driver");
Connection conn = null;
try
{
conn = DriverManager.getConnection(url + database, user, password);
System.out.println("Database changed");
} catch (SQLException e)
{
System.out.println(e.getMessage());
}
return conn;
}
2、执行查询语句返回查询结果
public static ArrayList<String[]> queryDB(String sql)
throws ClassNotFoundException
{
ArrayList<String[]> list = null;
try
{
list = new ArrayList<String[]>();
ResultSet result = statement.executeQuery(sql);
ResultSetMetaData rsd = result.getMetaData();
num = rsd.getColumnCount();
String[] columnName = new String[num];
for (int i = 1; i <= num; i++)
{
columnName[i - 1] = rsd.getColumnName(i);
queryLen[i - 1] = Math.max(queryLen[i - 1],
columnName[i - 1].length());
}
list.add(columnName);
while (result.next())
{
int index = 0;
String[] string = new String[num];
for (int i = 1; i <= num; i++)
{
string[i - 1] = String.valueOf(result.getObject(i));
queryLen[index] = Math.max(queryLen[index],
string[i - 1].length());
index++;
}
list.add(string);
}
} catch (SQLException e)
{
System.out.println(e.getMessage());
}
return list;
}
3、格式化输出
public static void main(String[] args) throws SQLException,
ClassNotFoundException, IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
Connection conn = null;
while (true)
{
System.out.print(">");
String command = br.readLine();
if (command.equals("mysql -u root -p"))
{
System.out.print("Enter password:");
String password = br.readLine();
System.out.print("mysql>");
String database = br.readLine();
if (database.split(" ")[0].equals("use"))
{
conn = getConn(database.split(" ")[1], "root", password);
if (conn == null)
continue;
}
break;
}
}
statement = conn.createStatement();
while (true)
{
System.out.print("\nmysql>");
String sql = br.readLine();
sql = sql.replace(";", "");
if (sql.trim().equals("quit"))
{
break;
} else if (sql.trim().startsWith("select"))
{
ArrayList<String[]> list = queryDB(sql);
for (int i = 0; i < list.size(); i++)
{
if (0 == i || 1 == i)
{
System.out.print("|");
for (int j = 0; j < list.get(i).length; j++)
{
for (int a = 0; a < queryLen[j]; a++)
{
System.out.print("-");
}
System.out.print("|");
}
System.out.println();
}
for (int j = 0; j < list.get(i).length; j++)
{
System.out.print("|" + list.get(i)[j]);
for (int k = list.get(i)[j].length(); k < queryLen[j]; k++)
{
System.out.print(" ");
}
}
System.out.println("|");
if (i == list.size() - 1)
{
System.out.print("|");
for (int j = 0; j < list.get(i).length; j++)
{
for (int a = 0; a < queryLen[j]; a++)
{
System.out.print("-");
}
System.out.print("|");
}
System.out.println();
}
}
} else
{
updateDB(sql);
}
}
}
运行测试：