public SqlNode visit(SqlNodeList list) {
SqlNodeList copy = new SqlNodeList(list.getParserPosition());
for (SqlNode node : list) {
copy.add(node.accept(this));
}
return copy;
}
public static SqlNode[] cloneArray(SqlNode[] nodes) {
SqlNode[] clones = (SqlNode[]) nodes.clone();
for (int i = 0; i < clones.length; i++) {
SqlNode node = clones[i];
if (node != null) {
clones[i] = (SqlNode) node.clone();
}
}
return clones;
}
public SqlNode findAgg(List<SqlNode> nodes) {
try {
for (SqlNode node : nodes) {
node.accept(this);
}
return null;
} catch (Util.FoundOne e) {
Util.swallow(e, null);
return (SqlNode) e.getNode();
}
}
boolean containsAnd(SqlNode node) {
try {
node.accept(this);
return false;
} catch (AndFinder.Found e) {
return true;
}
}
/**
* Returns whether two nodes are equal (using {@link #equalsDeep(SqlNode,boolean)}) or are both
* null.
*
* @param node1 First expression
* @param node2 Second expression
* @param fail Whether to throw {@link AssertionError} if expressions are not equal
*/
public static boolean equalDeep(SqlNode node1, SqlNode node2, boolean fail) {
if (node1 == null) {
return node2 == null;
} else if (node2 == null) {
return false;
} else {
return node1.equalsDeep(node2, fail);
}
}
/**
* 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);
}
}
}
/** Converts an expression "expr" into "expr AS alias". */
public static SqlNode addAlias(SqlNode expr, String alias) {
final SqlParserPos pos = expr.getParserPosition();
final SqlIdentifier id = new SqlIdentifier(alias, pos);
return SqlStdOperatorTable.AS.createCall(pos, expr, id);
}
