How can I get different datatypes from ResultSetMetaData in Java?

Question

I have a ResultSet that returns data of different types. The query is constructed dynamically so, at compile time, I don't know what type of value the query will return.

I have written the following code assuming that all results are Strings. But I want to get the type of each value too. How can I do this?

Below is the code I have written.

while (reportTable_rst.next()) {
    String column = reportTable_rst.getString(columnIterator);
}

At this point, I would like to get the column type, and get the value according to the data type.

Answer 1

The ResultSetMetaData.getColumnType(int column) returns a int value specifying the column type found in java.sql.Types.

Example:

Connection connection = DriverManager.getConnection(JDBC_URL, JDBC_USERNAME, JDBC_PASSWORD);
PreparedStatement statement = connection.prepareStatement(JDBC_SELECT);
ResultSet rs = statement.executeQuery();
PrintStream out = System.out;

if (rs != null) {
    while (rs.next()) {
        ResultSetMetaData rsmd = rs.getMetaData();
        for (int i = 1; i <= rsmd.getColumnCount(); i++) {
            if (i > 1) {
            out.print(",");
            }

            int type = rsmd.getColumnType(i);
            if (type == Types.VARCHAR || type == Types.CHAR) {
                out.print(rs.getString(i));
            } else {
                out.print(rs.getLong(i));
            }
        }

        out.println();
    }
}