danny0405 commented on a change in pull request #1374: [CALCITE-3138]
RelStructuredTypeFlattener doesn't restructure ROW type fields
URL: https://github.com/apache/calcite/pull/1374#discussion_r315646237
##########
File path:
core/src/main/java/org/apache/calcite/sql2rel/RelStructuredTypeFlattener.java
##########
@@ -587,86 +561,103 @@ private void flattenProjections(RewriteRexShuttle
shuttle,
List<Pair<RexNode, String>> flattenedExps) {
for (int i = 0; i < exps.size(); ++i) {
RexNode exp = exps.get(i);
- String fieldName =
- (fieldNames == null || fieldNames.get(i) == null)
- ? ("$" + i)
- : fieldNames.get(i);
- if (!prefix.equals("")) {
- fieldName = prefix + "$" + fieldName;
- }
+ String fieldName = extractName(fieldNames, prefix, i);
flattenProjection(shuttle, exp, fieldName, flattenedExps);
}
}
+ private String extractName(List<String> fieldNames, String prefix, int i) {
+ String fieldName = (fieldNames == null || fieldNames.get(i) == null)
+ ? ("$" + i)
+ : fieldNames.get(i);
+ if (!prefix.equals("")) {
+ fieldName = prefix + "$" + fieldName;
+ }
+ return fieldName;
+ }
+
private void flattenProjection(RewriteRexShuttle shuttle,
RexNode exp,
String fieldName,
List<Pair<RexNode, String>> flattenedExps) {
if (exp.getType().isStruct()) {
if (exp instanceof RexInputRef) {
- RexInputRef inputRef = (RexInputRef) exp;
-
- // expand to range
- RelDataType flattenedType =
- SqlTypeUtil.flattenRecordType(
- rexBuilder.getTypeFactory(),
- exp.getType(),
- null);
- List<RelDataTypeField> fieldList = flattenedType.getFieldList();
- int n = fieldList.size();
- for (int j = 0; j < n; ++j) {
- final Ord<RelDataType> newField =
- getNewFieldForOldInput(inputRef.getIndex(), j);
- flattenedExps.add(
- Pair.of(new RexInputRef(newField.i, newField.e),
- fieldName));
+ final int oldOrdinal = ((RexInputRef) exp).getIndex();
+ final int flattenFieldsCount = postFlattenSize(exp.getType());
+ for (int innerOrdinal = 0; innerOrdinal < flattenFieldsCount;
innerOrdinal++) {
+ Ord<RelDataType> newField = getNewFieldForOldInput(oldOrdinal,
innerOrdinal);
+ RexInputRef newRef = new RexInputRef(newField.i, newField.e);
+ flattenedExps.add(Pair.of(newRef, fieldName));
}
} else if (isConstructor(exp) || exp.isA(SqlKind.CAST)) {
// REVIEW jvs 27-Feb-2005: for cast, see corresponding note
// in RewriteRexShuttle
RexCall call = (RexCall) exp;
- if (exp.isA(SqlKind.NEW_SPECIFICATION)) {
- // For object constructors, prepend a FALSE null
- // indicator.
- flattenedExps.add(
- Pair.of(rexBuilder.makeLiteral(false),
- fieldName));
- } else if (exp.isA(SqlKind.CAST)) {
- if (RexLiteral.isNullLiteral(
- ((RexCall) exp).operands.get(0))) {
- // Translate CAST(NULL AS UDT) into
- // the correct number of null fields.
- flattenNullLiteral(
- exp.getType(),
- flattenedExps);
- return;
- }
+ if (exp.isA(SqlKind.CAST)
+ && RexLiteral.isNullLiteral(call.operands.get(0))) {
+ // Translate CAST(NULL AS UDT) into
+ // the correct number of null fields.
+ flattenNullLiteral(exp.getType(), flattenedExps);
+ return;
}
- flattenProjections(new RewriteRexShuttle(),
+ flattenProjections(shuttle,
call.getOperands(),
Collections.nCopies(call.getOperands().size(), null),
fieldName,
flattenedExps);
} else if (exp instanceof RexCall) {
// NOTE jvs 10-Feb-2005: This is a lame hack to keep special
// functions which return row types working.
-
- int j = 0;
RexNode newExp = exp;
- List<RexNode> oldOperands = ((RexCall) exp).getOperands();
- if (oldOperands.get(0) instanceof RexInputRef) {
- final RexInputRef inputRef = (RexInputRef) oldOperands.get(0);
- final Ord<RelDataType> newField =
- getNewFieldForOldInput(inputRef.getIndex());
- newExp = rexBuilder.makeCall(exp.getType(),
- ((RexCall) exp).getOperator(),
- ImmutableList.of(rexBuilder.makeInputRef(newField.e, newField.i),
- oldOperands.get(1)));
- }
- for (RelDataTypeField field : newExp.getType().getFieldList()) {
- flattenedExps.add(
- Pair.of(rexBuilder.makeFieldAccess(newExp, field.getIndex()),
- fieldName + "$" + (j++)));
+ List<RexNode> operands = ((RexCall) exp).getOperands();
+ SqlOperator operator = ((RexCall) exp).getOperator();
+
+ if (operator == SqlStdOperatorTable.ITEM
+ && operands.get(0).getType().isStruct()
+ && operands.get(1).isA(SqlKind.LITERAL)
+ && SqlTypeUtil.inCharFamily(operands.get(1).getType())) {
+ String literalString = ((RexLiteral)
operands.get(1)).getValueAs(String.class);
+ RexNode firstOp = operands.get(0);
+
+ if (firstOp instanceof RexInputRef) {
+ // when performed getting field from struct exp by field name
+ // and new input is flattened it's enough to refer target field by
index.
+ // But it's possible that requested field is also of type struct,
that's
+ // why we're trying to get range from to. For primitive just one
field will be in range.
+ int from = 0;
+ for (RelDataTypeField field : firstOp.getType().getFieldList()) {
+ if (literalString.equalsIgnoreCase(field.getName())) {
+ int oldOrdinal = ((RexInputRef) firstOp).getIndex();
+ int to = from + postFlattenSize(field.getType());
+ for (int newInnerOrdinal = from; newInnerOrdinal < to;
newInnerOrdinal++) {
+ Ord<RelDataType> newField =
getNewFieldForOldInput(oldOrdinal, newInnerOrdinal);
+ RexInputRef newRef = rexBuilder.makeInputRef(newField.e,
newField.i);
+ flattenedExps.add(Pair.of(newRef, fieldName));
+ }
+ break;
+ } else {
+ from += postFlattenSize(field.getType());
+ }
+ }
+ } else if (firstOp instanceof RexCall) {
+ // to get nested struct from return type of firstOp rex call,
+ // we need to flatten firstOp and get range of expressions which
+ // corresponding to desirable nested struct flattened fields
+ List<Pair<RexNode, String>> firstOpFlattenedExps = new
ArrayList<>();
+ flattenProjection(shuttle, firstOp, fieldName,
firstOpFlattenedExps);
+ int newInnerOrdinal = getNewInnerOrdinal(firstOp, literalString);
Review comment:
Maybe we should use a name pattern like `fieldName$0`, if it was in a deep
recursive, the name may be like `fieldName$0$0...`
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