Use the MaxCompute compiler to check scripts

Hover over the red error marker in the following code. The compiler displays the following error: expect 1 columns, actually have 2.

create table if not exists src(k bigint COMMENT '', V String COMMENT '');
insert overwrite table src
select a, wm_concat(',', a) from
    values(1,'a'),(1,'b'),(2,'x'),(2) t (a, b) group by a;
-- Error: expect 1 columns, actually have 2

Hover over the alert marker in the following code. The compiler displays the following alert: implicit conversion from STRING to DOUBLE, potential data loss, use CAST function to suppress.

create table if not exists dest(k bigint COMMENT '', V String COMMENT '');
create table if not exists upper_stream(id String COMMENT '', Value String COMMENT '') partitioned by (dt String);
insert overwrite table dest
    select k, value from src join upper_stream u on u.id = k; -- Compiler alert: implicit conversion from STRING to DOUBLE, potential data loss, use CAST function to suppress

An implicit conversion from STRING to DOUBLE can cause potential data loss. To avoid this, use the CAST function to explicitly convert the data type. For more information about data conversions, see Data type conversions.