Question

美好的一天！我有以下代码连接到H2数据库并使用Java执行查询。但是，只有CALL CSVWRITE对我有用。

这是我的代码：

public static Result tagImport() {
    String user = session("username");
    Connection connection = null;
    ResultSet resultSet = null;
    Statement statement = null;
    try {
        Class.forName("org.h2.Driver");
        connection = DriverManager.getConnection(
                "jdbc:h2:file:~/data/db", "sa", "");
        statement = connection.createStatement();
        resultSet = statement
                .executeQuery("CALL CSVWRITE('textfiles/tags.csv', 'SELECT * FROM TAG');");
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        try {
            resultSet.close();
            statement.close();
            connection.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
        return ok(dbSuccess.render(user));
}

public static Result tagExport() {
    String user = session("username");
    Connection connection = null;
    ResultSet resultSet = null;
    Statement statement = null;
    try {
        Class.forName("org.h2.Driver");
        connection = DriverManager.getConnection(
                "jdbc:h2:file:~/data/db", "sa", "");
        statement = connection.createStatement();
        resultSet = statement.executeQuery("MERGE INTO TAG (SELECT * FROM CSVREAD('textfiles/tags.csv'));");
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        try {
            resultSet.close();
            statement.close();
            connection.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
        return ok(dbSuccess.render(user));
}

如您所见，唯一的区别是要执行的查询。我对两者使用了相同的方法，但它似乎不适用于tagExport函数。我只想再次连接到数据库并将使用tagImport函数创建的csv文件插入表中。请帮助。谢谢！

Answer 1

对于MERGE声明，您需要使用Statement.executeUpdate()代替executeQuery()

H2数据库，使用Java CSVREAD合并到表中

1 个答案: