I want to convert a resultset to a string. I have tried everything but it always gives no data found. Please provide some solution

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陌清茗
陌清茗 2020-12-21 06:59

I want to convert a ResultSet to a string. I have tried everything but it always gives no data found. Please provide some solution

3条回答
  •  长情又很酷
    2020-12-21 07:09

    Try this:

    StringBuilder builder = new StringBuilder();
    int columnCount = resultSet.getMetaData().getColumnCount();
    while (resultSet.next()) {
        for (int i = 0; i < columnCount;) {
            builder.append(resultSet.getString(i + 1));
            if (++i < columnCount) builder.append(",");
        }
        builder.append("\r\n");
    }
    String resultSetAsString = builder.toString();
    

    You may need to tweak the string format a bit more to suit your needs. Alternatively, you can also map the ResultSet to a collection of Javabeans whose class has the Object#toString() overriden.

    E.g.

    public class Row {
        private Long id;
        private String columnName1;
        private String columnName2;
        // Add/generate constructors, getters and setters.
    
        public String toString() {
            return String.format("Row[id=%d,columName1=%s,columnName2=%s", id, columnName1, columnName2);
        }
    }
    

    with

    List rows = new ArrayList();
    while (resultSet.next()) {
        Row row = new Row();
        row.setId(resultSet.getLong("id"));
        row.setColumnName1(resultSet.getString("columnName1"));
        row.setColumnName2(resultSet.getString("columnName2"));
        rows.add(row);
    }
    
    // To display it:
    for (Row row : rows) {
        System.out.println(row);
    }
    

    As to your actual problem (you apparently got an exception with the words "no data found"), you'll need to provide the stacktrace and the code snippet which caused this, so that you'll get better suited answers.

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