Question

我正在使用本地数据库在JDBC，MySql中学习基本的CRUD，问题是对于每个Crud方法，我必须指定要使用的模式。是否有任何方法可以放置一次？当我将使用h2数据库对其进行测试时，这将成为一个问题。

` 公共类DbConnection实现ConnectionProvider {

private MysqlDataSource datasource = new MysqlDataSource();


/* FileNotFoundException,  setUseSSL= false not working
*TODO: fix fileNotFoundException , properties password and username error
*/
public DbConnection() {
    Properties properties = new Properties();
    try {
        //datasource.setUseSSL(false);
        properties.load(new FileInputStream("src/main/java/ConnectionSource.properties"));
    } catch (IOException  e) {
        e.printStackTrace();
    }
    String password = properties.getProperty("password");
    String serverName = properties.getProperty("host");
    String user = properties.getProperty("user");
    datasource.setPassword(password);
    datasource.setUser(user);
    datasource.setServerName(serverName);
}

//For different Databases and users
public DbConnection(String password, String user, String serverName){
    datasource.setPassword(password);
    datasource.setUser(user);
    datasource.setServerName(serverName);
}


@Override
public Connection getConnection() throws IOException, SQLException, ClassNotFoundException {
    return datasource.getConnection();
}

} The Provider:公用接口ConnectionProvider {

Connection getConnection() throws IOException, SQLException, ClassNotFoundException;

}`

我在哪里指定： `public void createTableSubjects（MysqlDataSource dataSource）{

    FileReader file = new FileReader();
    file.readFromFileSubjects();
    String query = "CREATE TABLE  IF NOT EXISTS " + file.getItemFromList(1) + "( " +
            "  " + file.getItemFromList(2) + "       " + file.getItemFromList(22) + " unique not null," +
            "  " + file.getItemFromList(3) + "       " + file.getItemFromList(22) + " default 'null'," +
            "  " + file.getItemFromList(4) + "       " + file.getItemFromList(22) + " default 'null'," +
            "  " + file.getItemFromList(5) + "       " + file.getItemFromList(22) + " default 'null'," +
            "  " + file.getItemFromList(6) + "       " + file.getItemFromList(22) + " default 'null'," +
            "  " + file.getItemFromList(7) + "       " + file.getItemFromList(22) + " default 'null'," +
            "  PRIMARY KEY (" + file.getItemFromList(2) + ")" +
            ")";

    /**Så ingen poeng med å  bruke preparedStatement her**/
    try (Connection con = dataSource.getConnection()) {
        Statement stmt = con.createStatement();
        stmt.executeUpdate("USE Time_edit"); //TODO: how to specify once only?
        stmt.executeUpdate(query);

        System.out.println("New Table 'Subjects' created");
    } catch (SQLException e) {
        System.out.println("Failed to create Table 'Subjects' \n" + e.getMessage());
        e.printStackTrace();
    }
}

`

Answer 1

在数据源上设置数据库名称：

datasource.setPassword(password);
datasource.setUser(user);
datasource.setServerName(serverName);
datasource.setDatabaseName("Time_edit");

如何指定一次使用哪个架构？

1 个答案: