use of io.confluent.ksql.parser.tree.JoinUsing in project ksql by confluentinc.
the class AstBuilder method visitJoinRelation.
// *************** from clause *****************
@Override
public Node visitJoinRelation(SqlBaseParser.JoinRelationContext context) {
Relation left = (Relation) visit(context.left);
Relation right;
if (context.CROSS() != null) {
right = (Relation) visit(context.right);
return new Join(getLocation(context), Join.Type.CROSS, left, right, Optional.<JoinCriteria>empty());
}
JoinCriteria criteria;
if (context.NATURAL() != null) {
right = (Relation) visit(context.right);
criteria = new NaturalJoin();
} else {
right = (Relation) visit(context.rightRelation);
if (context.joinCriteria().ON() != null) {
criteria = new JoinOn((Expression) visit(context.joinCriteria().booleanExpression()));
} else if (context.joinCriteria().USING() != null) {
List<String> columns = context.joinCriteria().identifier().stream().map(AstBuilder::getIdentifierText).collect(toList());
criteria = new JoinUsing(columns);
} else {
throw new IllegalArgumentException("Unsupported join criteria");
}
}
Join.Type joinType;
if (context.joinType().LEFT() != null) {
joinType = Join.Type.LEFT;
} else if (context.joinType().RIGHT() != null) {
joinType = Join.Type.RIGHT;
} else if (context.joinType().FULL() != null) {
joinType = Join.Type.FULL;
} else {
joinType = Join.Type.INNER;
}
return new Join(getLocation(context), joinType, left, right, Optional.of(criteria));
}
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