private static ASTNode replaceAlias(final ASTNode expr, final CubeQueryContext cubeql)
throws SemanticException {
ASTNode finalAST = HQLParser.copyAST(expr);
HQLParser.bft(
finalAST,
new ASTNodeVisitor() {
@Override
public void visit(TreeNode visited) {
ASTNode node = visited.getNode();
ASTNode parent = null;
if (visited.getParent() != null) {
parent = visited.getParent().getNode();
}
if (node.getToken().getType() == TOK_TABLE_OR_COL
&& (parent != null && parent.getToken().getType() == DOT)) {
ASTNode current = (ASTNode) node.getChild(0);
if (current.getToken().getType() == Identifier) {
String tableName = current.getToken().getText().toLowerCase();
String alias = cubeql.getAliasForTableName(tableName);
if (!alias.equalsIgnoreCase(tableName)) {
node.setChild(0, new ASTNode(new CommonToken(HiveParser.Identifier, alias)));
}
}
}
}
});
return finalAST;
}
private static void replaceColumnInAST(
ASTNode expr, final String toReplace, final ASTNode columnAST) throws SemanticException {
if (expr == null) {
return;
}
// Traverse the tree and resolve expression columns
HQLParser.bft(
expr,
new ASTNodeVisitor() {
@Override
public void visit(TreeNode visited) throws SemanticException {
ASTNode node = visited.getNode();
int childcount = node.getChildCount();
for (int i = 0; i < childcount; i++) {
ASTNode current = (ASTNode) node.getChild(i);
if (current.getToken().getType() == TOK_TABLE_OR_COL
&& (node != null && node.getToken().getType() != DOT)) {
// Take child ident.totext
ASTNode ident = (ASTNode) current.getChild(0);
String column = ident.getText().toLowerCase();
if (toReplace.equals(column)) {
node.setChild(i, HQLParser.copyAST(columnAST));
}
} else if (current.getToken().getType() == DOT) {
// This is for the case where column name is prefixed by table name
// or table alias
// For example 'select fact.id, dim2.id ...'
// Right child is the column name, left child.ident is table name
ASTNode tabident = HQLParser.findNodeByPath(current, TOK_TABLE_OR_COL, Identifier);
ASTNode colIdent = (ASTNode) current.getChild(1);
String column = colIdent.getText().toLowerCase();
if (toReplace.equals(column)) {
node.setChild(i, HQLParser.copyAST(columnAST));
}
}
}
}
});
}
private void replaceAST(final CubeQueryContext cubeql, ASTNode node) throws SemanticException {
if (node == null) {
return;
}
// Traverse the tree and resolve expression columns
HQLParser.bft(
node,
new ASTNodeVisitor() {
@Override
public void visit(TreeNode visited) throws SemanticException {
ASTNode node = visited.getNode();
int childcount = node.getChildCount();
for (int i = 0; i < childcount; i++) {
ASTNode current = (ASTNode) node.getChild(i);
if (current.getToken().getType() == DOT) {
// This is for the case where column name is prefixed by table name
// or table alias
// For example 'select fact.id, dim2.id ...'
// Right child is the column name, left child.ident is table name
ASTNode tabident =
HQLParser.findNodeByPath(current, TOK_TABLE_OR_COL, Identifier);
ASTNode colIdent = (ASTNode) current.getChild(1);
String column = colIdent.getText().toLowerCase();
if (pickedExpressions.containsKey(column)) {
PickedExpression expr =
getPickedExpression(column, tabident.getText().toLowerCase());
if (expr != null) {
node.setChild(i, replaceAlias(expr.pickedCtx.finalAST, cubeql));
}
}
}
}
}
});
}