public RelDataType inferReturnType(SqlOperatorBinding opBinding) {
assert opBinding.getOperandCount() == 1;
final RelDataType recordMultisetType = opBinding.getOperandType(0);
RelDataType multisetType = recordMultisetType.getComponentType();
assert multisetType != null : "expected a multiset type: " + recordMultisetType;
final List<RelDataTypeField> fields = multisetType.getFieldList();
assert fields.size() > 0;
final RelDataType firstColType = fields.get(0).getType();
return opBinding.getTypeFactory().createMultisetType(firstColType, -1);
}
public static RelDataType createTypeFromProjection(
RelDataType type,
List<String> columnNameList,
RelDataTypeFactory typeFactory,
boolean caseSensitive) {
// If the names in columnNameList and type have case-sensitive differences,
// the resulting type will use those from type. These are presumably more
// canonical.
final List<RelDataTypeField> fields = new ArrayList<RelDataTypeField>(columnNameList.size());
for (String name : columnNameList) {
RelDataTypeField field = type.getField(name, caseSensitive);
fields.add(type.getFieldList().get(field.getIndex()));
}
return typeFactory.createStructType(fields);
}
public RelDataType inferReturnType(SqlOperatorBinding opBinding) {
assert opBinding.getOperandCount() == 1;
final RelDataType recordType = opBinding.getOperandType(0);
boolean isStruct = recordType.isStruct();
int fieldCount = recordType.getFieldCount();
assert isStruct && (fieldCount == 1);
RelDataTypeField fieldType = recordType.getFieldList().get(0);
assert fieldType != null : "expected a record type with one field: " + recordType;
final RelDataType firstColType = fieldType.getType();
return opBinding.getTypeFactory().createTypeWithNullability(firstColType, true);
}
private List<RelCollation> deduceMonotonicity(SqlValidatorTable table) {
final RelDataType rowType = table.getRowType();
final List<RelCollation> collationList = new ArrayList<RelCollation>();
// Deduce which fields the table is sorted on.
int i = -1;
for (RelDataTypeField field : rowType.getFieldList()) {
++i;
final SqlMonotonicity monotonicity = table.getMonotonicity(field.getName());
if (monotonicity != SqlMonotonicity.NOT_MONOTONIC) {
final RelFieldCollation.Direction direction =
monotonicity.isDecreasing()
? RelFieldCollation.Direction.DESCENDING
: RelFieldCollation.Direction.ASCENDING;
collationList.add(
RelCollationImpl.of(
new RelFieldCollation(
i, direction, RelFieldCollation.NullDirection.UNSPECIFIED)));
}
}
return collationList;
}