/**
* Resolves a multi-part identifier such as "SCHEMA.EMP.EMPNO" to a namespace. The returned
* namespace may represent a schema, table, column, etc.
*
* @pre names.size() > 0
* @post return != null
*/
public static SqlValidatorNamespace lookup(SqlValidatorScope scope, List<String> names) {
Util.pre(names.size() > 0, "names.size() > 0");
SqlValidatorNamespace namespace = null;
for (int i = 0; i < names.size(); i++) {
String name = names.get(i);
if (i == 0) {
namespace = scope.resolve(name, null, null);
} else {
namespace = namespace.lookupChild(name);
}
}
Util.permAssert(namespace != null, "post: namespace != null");
return namespace;
}
public RelNode convertSqlToRel(String sql) {
Util.pre(sql != null, "sql != null");
final SqlNode sqlQuery;
try {
sqlQuery = parseQuery(sql);
} catch (Exception e) {
throw Util.newInternal(e); // todo: better handling
}
final RelDataTypeFactory typeFactory = getTypeFactory();
final Prepare.CatalogReader catalogReader = createCatalogReader(typeFactory);
final SqlValidator validator = createValidator(catalogReader, typeFactory);
final SqlToRelConverter converter =
createSqlToRelConverter(validator, catalogReader, typeFactory);
converter.setTrimUnusedFields(true);
final SqlNode validatedQuery = validator.validate(sqlQuery);
final RelNode rel = converter.convertQuery(validatedQuery, false, true);
Util.post(rel != null, "return != null");
return rel;
}
/** Returns whether an array of expressions has any common sub-expressions. */
public static boolean containCommonExprs(RexNode[] exprs, boolean fail) {
final ExpressionNormalizer visitor = new ExpressionNormalizer(false);
for (int i = 0; i < exprs.length; i++) {
try {
exprs[i].accept(visitor);
} catch (ExpressionNormalizer.SubExprExistsException e) {
Util.swallow(e, null);
assert !fail;
}
}
return false;
}
/**
* Replaces the operands of a call. The new operands' types must match the old operands' types.
*/
public static RexCall replaceOperands(RexCall call, RexNode[] operands) {
if (call.operands == operands) {
return call;
}
for (int i = 0; i < operands.length; i++) {
RelDataType oldType = call.operands[i].getType();
RelDataType newType = operands[i].getType();
if (!oldType.isNullable() && newType.isNullable()) {
throw Util.newInternal("invalid nullability");
}
assert (oldType.toString().equals(newType.toString()));
}
return new RexCall(call.getType(), call.getOperator(), operands);
}
/**
* Returns whether a given tree contains any {@link org.eigenbase.rex.RexFieldAccess} nodes.
*
* @param node a RexNode tree
*/
public static boolean containsFieldAccess(RexNode node) {
try {
RexVisitor<Void> visitor =
new RexVisitorImpl<Void>(true) {
public Void visitFieldAccess(RexFieldAccess fieldAccess) {
throw new Util.FoundOne(fieldAccess);
}
};
node.accept(visitor);
return false;
} catch (Util.FoundOne e) {
Util.swallow(e, null);
return true;
}
}
/**
* Returns whether a given tree contains any {link RexInputRef} nodes.
*
* @param node a RexNode tree
*/
public static boolean containsInputRef(RexNode node) {
try {
RexVisitor<Void> visitor =
new RexVisitorImpl<Void>(true) {
public Void visitInputRef(RexInputRef inputRef) {
throw new Util.FoundOne(inputRef);
}
};
node.accept(visitor);
return false;
} catch (Util.FoundOne e) {
Util.swallow(e, null);
return true;
}
}
public static void getSchemaObjectMonikers(
SqlValidatorCatalogReader catalogReader, List<String> names, List<SqlMoniker> hints) {
// Assume that the last name is 'dummy' or similar.
List<String> subNames = Util.skipLast(names);
hints.addAll(catalogReader.getAllSchemaObjectNames(subNames));
// If the name has length 0, try prepending the name of the default
// schema. So, the empty name would yield a list of tables in the
// default schema, as well as a list of schemas from the above code.
if (subNames.size() == 0) {
hints.addAll(
catalogReader.getAllSchemaObjectNames(
Collections.singletonList(catalogReader.getSchemaName())));
}
}
/**
* Returns whether an array of expressions contains a forward reference. That is, if expression #i
* contains a {@link RexInputRef} referencing field i or greater.
*
* @param exprs Array of expressions
* @param inputRowType Input row type
* @param fail Whether to assert if there is a forward reference
* @return Whether there is a forward reference
*/
public static boolean containForwardRefs(
RexNode[] exprs, RelDataType inputRowType, boolean fail) {
final ForwardRefFinder visitor = new ForwardRefFinder(inputRowType);
for (int i = 0; i < exprs.length; i++) {
RexNode expr = exprs[i];
visitor.setLimit(i); // field cannot refer to self or later field
try {
expr.accept(visitor);
} catch (ForwardRefFinder.IllegalForwardRefException e) {
Util.swallow(e, null);
assert !fail : "illegal forward reference in " + expr;
return true;
}
}
return false;
}
/**
* Returns whether a given node contains a RexCall with a specified operator
*
* @param operator to look for
* @param node a RexNode tree
*/
public static RexCall findOperatorCall(final SqlOperator operator, RexNode node) {
try {
RexVisitor<Void> visitor =
new RexVisitorImpl<Void>(true) {
public Void visitCall(RexCall call) {
if (call.getOperator().equals(operator)) {
throw new Util.FoundOne(call);
}
return super.visitCall(call);
}
};
node.accept(visitor);
return null;
} catch (Util.FoundOne e) {
Util.swallow(e, null);
return (RexCall) e.getNode();
}
}
/**
* Derives an alias for a node, and invents a mangled identifier if it cannot.
*
* <p>Examples:
*
* <ul>
* <li>Alias: "1 + 2 as foo" yields "foo"
* <li>Identifier: "foo.bar.baz" yields "baz"
* <li>Anything else yields "expr$<i>ordinal</i>"
* </ul>
*
* @return An alias, if one can be derived; or a synthetic alias "expr$<i>ordinal</i>" if ordinal
* >= 0; otherwise null
*/
public static String getAlias(SqlNode node, int ordinal) {
switch (node.getKind()) {
case AS:
// E.g. "1 + 2 as foo" --> "foo"
return ((SqlCall) node).getOperands()[1].toString();
case OVER:
// E.g. "bids over w" --> "bids"
return getAlias(((SqlCall) node).getOperands()[0], ordinal);
case IDENTIFIER:
// E.g. "foo.bar" --> "bar"
return Util.last(((SqlIdentifier) node).names);
default:
if (ordinal < 0) {
return null;
} else {
return SqlUtil.deriveAliasFromOrdinal(ordinal);
}
}
}
SubExprExistsException(RexNode expr) {
Util.discard(expr);
}
public String apply(String original, int attempt, int size) {
return Util.first(original, "$f") + size;
}
public String apply(String original, int attempt, int size) {
return Util.first(original, "EXPR$") + attempt;
}
public String getSignatureTemplate(int operandsCount) {
Util.discard(operandsCount);
return "{0}({1} FROM {2})";
}
/**
* Reduces a list of operators and arguments according to the rules of precedence and
* associativity. Returns the ordinal of the node which replaced the expression.
*
* <p>The default implementation throws {@link UnsupportedOperationException}.
*
* @param ordinal indicating the ordinal of the current operator in the list on which a possible
* reduction can be made
* @param list List of alternating {@link org.eigenbase.sql.parser.SqlParserUtil.ToTreeListItem}
* and {@link SqlNode}
* @return ordinal of the node which replaced the expression
*/
public int reduceExpr(int ordinal, List<Object> list) {
throw Util.needToImplement(this);
}
public String getSignatureTemplate(final int operandsCount) {
Util.discard(operandsCount);
return "{1} {0} {2} AND {3}";
}