/**
* Looks up a field with a given name, returning null if not found.
*
* @param rowType Row type
* @param columnName Field name
* @return Field, or null if not found
*/
public static RelDataTypeField lookupField(
boolean caseSensitive, final RelDataType rowType, String columnName) {
RelDataTypeField field = rowType.getField(columnName, caseSensitive);
if (field != null) {
return field;
}
// If record type is flagged as having "any field you ask for",
// return a type. (TODO: Better way to mark accommodating types.)
RelDataTypeField extra = RelDataTypeImpl.extra(rowType);
if (extra != null) {
return new RelDataTypeFieldImpl(columnName, -1, extra.getType());
}
return null;
}
RelProtoDataType getRelDataType(
DatabaseMetaData metaData, String catalogName, String schemaName, String tableName)
throws SQLException {
final ResultSet resultSet = metaData.getColumns(catalogName, schemaName, tableName, null);
// Temporary type factory, just for the duration of this method. Allowable
// because we're creating a proto-type, not a type; before being used, the
// proto-type will be copied into a real type factory.
final RelDataTypeFactory typeFactory = new SqlTypeFactoryImpl();
final RelDataTypeFactory.FieldInfoBuilder fieldInfo = typeFactory.builder();
while (resultSet.next()) {
final String columnName = resultSet.getString(4);
final int dataType = resultSet.getInt(5);
final String typeString = resultSet.getString(6);
final int size = resultSet.getInt(7);
final int scale = resultSet.getInt(9);
RelDataType sqlType = sqlType(typeFactory, dataType, size, scale, typeString);
boolean nullable = resultSet.getBoolean(11);
fieldInfo.add(columnName, sqlType).nullable(nullable);
}
resultSet.close();
return RelDataTypeImpl.proto(fieldInfo.build());
}