public RelDataType resolveColumn(String name, SqlNode ctx) {
final SqlValidatorNamespace selectNs = validator.getNamespace(select);
final RelDataType rowType = selectNs.getRowType();
final RelDataTypeField field = validator.catalogReader.field(rowType, name);
if (field != null) {
return field.getType();
}
final SqlValidatorScope selectScope = validator.getSelectScope(select);
return selectScope.resolveColumn(name, ctx);
}
// implement RelDataType
public RelDataTypeField getField(String fieldName, boolean caseSensitive) {
for (RelDataTypeField field : fieldList) {
if (Util.match(caseSensitive, field.getName(), fieldName)) {
return field;
}
}
// Extra field
if (fieldList.size() > 0) {
final RelDataTypeField lastField = Iterables.getLast(fieldList);
if (lastField.getName().equals("_extra")) {
return new RelDataTypeFieldImpl(fieldName, -1, lastField.getType());
}
}
return null;
}
/**
* 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;
}
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);
}
/**
* Generates a cast for a row type.
*
* @param rexBuilder RexBuilder to use for constructing casts
* @param lhsRowType target row type
* @param rhsExps expressions to be cast
* @return cast expressions
*/
public static RexNode[] generateCastExpressions(
RexBuilder rexBuilder, RelDataType lhsRowType, RexNode[] rhsExps) {
RelDataTypeField[] lhsFields = lhsRowType.getFields();
final int fieldCount = lhsFields.length;
RexNode[] castExps = new RexNode[fieldCount];
assert fieldCount == rhsExps.length;
for (int i = 0; i < fieldCount; ++i) {
RelDataTypeField lhsField = lhsFields[i];
RelDataType lhsType = lhsField.getType();
RelDataType rhsType = rhsExps[i].getType();
if (lhsType.equals(rhsType)) {
castExps[i] = rhsExps[i];
} else {
castExps[i] = rexBuilder.makeCast(lhsType, rhsExps[i]);
}
}
return castExps;
}