/**
* Iterate through the nodes in the FROM clause to build a column resolver used to lookup a column
* given the name and alias.
*
* @param statement the select statement
* @return the column resolver
* @throws SQLException
* @throws SQLFeatureNotSupportedException if unsupported constructs appear in the FROM clause
* @throws TableNotFoundException if table name not found in schema
*/
public static ColumnResolver getResolverForQuery(
SelectStatement statement, PhoenixConnection connection) throws SQLException {
List<TableNode> fromNodes = statement.getFrom();
if (!statement.isJoin() && fromNodes.get(0) instanceof NamedTableNode)
return new SingleTableColumnResolver(connection, (NamedTableNode) fromNodes.get(0), true);
MultiTableColumnResolver visitor = new MultiTableColumnResolver(connection);
for (TableNode node : fromNodes) {
node.accept(visitor);
}
return visitor;
}
