Java Code Examples for org.apache.calcite.linq4j.Enumerable#select()

The following examples show how to use org.apache.calcite.linq4j.Enumerable#select() . You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.
Example 1
Source File: Smalls.java    From calcite with Apache License 2.0 6 votes vote down vote up 
/**
 * A function that adds a number to the first column of input cursor
 */
public static QueryableTable processCursor(final int offset,
    final Enumerable<Object[]> a) {
  return new AbstractQueryableTable(Object[].class) {
    public RelDataType getRowType(RelDataTypeFactory typeFactory) {
      return typeFactory.builder()
          .add("result", SqlTypeName.INTEGER)
          .build();
    }

    public <T> Queryable<T> asQueryable(QueryProvider queryProvider,
        SchemaPlus schema, String tableName) {
      final Enumerable<Integer> enumerable =
          a.select(a0 -> offset + ((Integer) a0[0]));
      //noinspection unchecked
      return (Queryable) enumerable.asQueryable();
    }
  };
}
Example 2
Source File: MycatReflectiveSchema.java    From Mycat2 with GNU General Public License v3.0 5 votes vote down vote up 
public Enumerable<Object[]> scan(DataContext root) {
    Enumerable enumerable = this.enumerable.get();
    if (elementType == Object[].class) {
    //noinspection unchecked
    return enumerable;
  } else {
    //noinspection unchecked
    return enumerable.select(new FieldSelector((Class) elementType));
  }
}
Example 3
Source File: Enumerables.java    From calcite with Apache License 2.0 4 votes vote down vote up 
/** Converts an enumerable over singleton arrays into the enumerable of their
 * first elements. */
public static <E> Enumerable<E> slice0(Enumerable<E[]> enumerable) {
  //noinspection unchecked
  return enumerable.select(elements -> elements[0]);
}
Example 4
Source File: Enumerables.java    From calcite with Apache License 2.0 4 votes vote down vote up 
/** Converts an {@link Enumerable} over object arrays into an
 * {@link Enumerable} over {@link Row} objects. */
public static Enumerable<Row> toRow(final Enumerable<Object[]> enumerable) {
  return enumerable.select((Function1<Object[], Row>) Row::asCopy);
}