Examples with TryExpression com.facebook.presto.sql.tree.TryExpression used on opensource projects

Example 1 with TryExpression

use of com.facebook.presto.sql.tree.TryExpression in project presto by prestodb.

the class AstBuilder method visitFunctionCall.

@Override
public Node visitFunctionCall(SqlBaseParser.FunctionCallContext context) {
    Optional<Expression> filter = visitIfPresent(context.filter(), Expression.class);
    Optional<Window> window = visitIfPresent(context.over(), Window.class);
    QualifiedName name = getQualifiedName(context.qualifiedName());
    boolean distinct = isDistinct(context.setQuantifier());
    if (name.toString().equalsIgnoreCase("if")) {
        check(context.expression().size() == 2 || context.expression().size() == 3, "Invalid number of arguments for 'if' function", context);
        check(!window.isPresent(), "OVER clause not valid for 'if' function", context);
        check(!distinct, "DISTINCT not valid for 'if' function", context);
        Expression elseExpression = null;
        if (context.expression().size() == 3) {
            elseExpression = (Expression) visit(context.expression(2));
        }
        return new IfExpression(getLocation(context), (Expression) visit(context.expression(0)), (Expression) visit(context.expression(1)), elseExpression);
    }
    if (name.toString().equalsIgnoreCase("nullif")) {
        check(context.expression().size() == 2, "Invalid number of arguments for 'nullif' function", context);
        check(!window.isPresent(), "OVER clause not valid for 'nullif' function", context);
        check(!distinct, "DISTINCT not valid for 'nullif' function", context);
        return new NullIfExpression(getLocation(context), (Expression) visit(context.expression(0)), (Expression) visit(context.expression(1)));
    }
    if (name.toString().equalsIgnoreCase("coalesce")) {
        check(!window.isPresent(), "OVER clause not valid for 'coalesce' function", context);
        check(!distinct, "DISTINCT not valid for 'coalesce' function", context);
        return new CoalesceExpression(getLocation(context), visit(context.expression(), Expression.class));
    }
    if (name.toString().equalsIgnoreCase("try")) {
        check(context.expression().size() == 1, "The 'try' function must have exactly one argument", context);
        check(!window.isPresent(), "OVER clause not valid for 'try' function", context);
        check(!distinct, "DISTINCT not valid for 'try' function", context);
        return new TryExpression(getLocation(context), (Expression) visit(getOnlyElement(context.expression())));
    }
    return new FunctionCall(getLocation(context), getQualifiedName(context.qualifiedName()), window, filter, distinct, visit(context.expression(), Expression.class));
}