static ASTNode replaceAliases(ASTNode node, int nodePos, Map<String, String> colToTableAlias) {
if (node == null) {
return node;
}
int nodeType = node.getToken().getType();
if (nodeType == HiveParser.TOK_TABLE_OR_COL || nodeType == HiveParser.DOT) {
String colName = HQLParser.getColName(node);
String newAlias = colToTableAlias.get(colName.toLowerCase());
if (StringUtils.isBlank(newAlias)) {
return node;
}
if (nodeType == HiveParser.DOT) {
// No need to create a new node, just replace the table name ident
ASTNode aliasNode = (ASTNode) node.getChild(0);
ASTNode newAliasIdent = new ASTNode(new CommonToken(HiveParser.Identifier, newAlias));
aliasNode.setChild(0, newAliasIdent);
} else {
// Just a column ref, we need to make it alias.col
// '.' will become the parent node
ASTNode dot = new ASTNode(new CommonToken(HiveParser.DOT, "."));
ASTNode aliasIdentNode = new ASTNode(new CommonToken(HiveParser.Identifier, newAlias));
ASTNode tabRefNode =
new ASTNode(new CommonToken(HiveParser.TOK_TABLE_OR_COL, "TOK_TABLE_OR_COL"));
tabRefNode.addChild(aliasIdentNode);
dot.addChild(tabRefNode);
ASTNode colIdentNode = new ASTNode(new CommonToken(HiveParser.Identifier, colName));
dot.addChild(colIdentNode);
ASTNode parent = (ASTNode) node.getParent();
if (parent != null) {
parent.setChild(nodePos, dot);
} else {
return dot;
}
}
} else {
// recurse down
for (int i = 0; i < node.getChildCount(); i++) {
ASTNode child = (ASTNode) node.getChild(i);
replaceAliases(child, i, colToTableAlias);
}
}
return node;
}
private ASTNode getQueryASTNode(ASTNode node) {
while (node != null && node.getType() != HiveParser.TOK_QUERY) {
node = (ASTNode) node.getParent();
}
return node;
}