code-jdbc-find-interval-columns.md
// Determine the interval data types by examining the database
// metadata.
DatabaseMetaData dbmd = conn.getMetaData();
ResultSet dbMeta = dbmd.getColumns(null, null, "interval_demo", null);
int colcount = 0;
while (dbMeta.next()) {
// Get the metadata type for a column.
int javaType = dbMeta.getInt("DATA_TYPE");
System.out.println("Column " + ++colcount + " Type name is " +
dbMeta.getString("TYPE_NAME"));
if(javaType == Types.OTHER) {
// The SQL_DATETIME_SUB column in the metadata tells you
// Specifically which subtype of interval you have.
// The VerticaDayTimeInterval.isDayTimeInterval()
// methods tells you if that value is a day time.
//
int intervalType = dbMeta.getInt("SQL_DATETIME_SUB");
if(VerticaDayTimeInterval.isDayTimeInterval(intervalType)) {
// Now you know it is one of the 10 day/time interval types.
// When you select this column you can cast to
// VerticaDayTimeInterval.
// You can get more specific by checking intervalType
// against each of the 10 constants directly, but
// they all are represented by the same object.
System.out.println("column " + colcount + " is a " +
"VerticaDayTimeInterval intervalType = "
+ intervalType);
} else if(VerticaYearMonthInterval.isYearMonthInterval(
intervalType)) {
//now you know it is one of the 3 year/month intervals,
//and you can select the column and cast to
// VerticaYearMonthInterval
System.out.println("column " + colcount + " is a " +
"VerticaDayTimeInterval intervalType = "
+ intervalType);
} else {
System.out.println("Not an interval type.");
}
}
}