Alias hides right table column in join

[euyuil]

Describe the bug

Failure happens when selecting a constant renaming to the same name with an existing column of a joined table which is also in where clause.

How to reproduce

• Which ClickHouse server version to use: version 20.3.12.112 (official build)

• Which interface to use, if matters: No matter.

• Non-default settings, if any: Not any.

• CREATE TABLE statements for all tables involved

CREATE TABLE test_a_table (
    name String,
    a_col String
)
Engine = MergeTree()
ORDER BY name;

CREATE TABLE test_b_table (
    name String,
    b_col String,
    some_val String
)
Engine = MergeTree()
ORDER BY name;

• Sample data for all these tables, use clickhouse-obfuscator if necessary

No data is needed to reproduce the error.

• Queries to run that lead to unexpected result

SELECT
    b.name name,
    a.a_col a_col,
    b.b_col b_col,
    'N' some_val
from test_a_table a
join test_b_table b on a.name = b.name
where b.some_val = 'Y';

Expected behavior
A clear and concise description of what you expected to happen.

The query is expected to be successful.

Error message and/or stacktrace
If applicable, add screenshots to help explain your problem.

Code: 47, e.displayText() = DB::Exception: Unknown identifier: some_val there are columns: name, a_col, b.name, b_col (version 20.3.12.112 (official build))

Additional context
Add any other context about the problem here.

These queries are successful:

SELECT
    b.name name,
    a.a_col a_col,
    b.b_col b_col   -- some_val not selected
from test_a_table a
join test_b_table b on a.name = b.name
where b.some_val = 'Y';

SELECT
    b.name name,
    a.a_col a_col,
    b.b_col b_col,
    b.some_val some_val   -- use b.some_val instead of a constant
from test_a_table a
join test_b_table b on a.name = b.name
where b.some_val = 'Y';

SELECT
    b.name name,
    a.a_col a_col,
    b.b_col b_col,
    'N' some_val2   -- do not rename to some_val
from test_a_table a
join test_b_table b on a.name = b.name
where b.some_val = 'Y';

SELECT
    b.name name,
    a.a_col a_col,
    b.b_col b_col,
    'N' some_val
from test_a_table a
join test_b_table b on a.name = b.name;   -- no where clause

SELECT
    b.name name,
    a.a_col a_col,
    b.b_col b_col,
    if(b.some_val='','N','N') some_val   -- an interesting workaround...
from test_a_table a
join test_b_table b on a.name = b.name
where b.some_val = 'Y';

However, this won't work either:

SELECT
    b.name name,
    a.a_col a_col,
    b.b_col b_col,
    if(1,'N',b.some_val) some_val   -- b.some_val is not actually evaluated
from test_a_table a
join test_b_table b on a.name = b.name
where b.some_val = 'Y';

[DouMiaoO-Oo]

I have a similar error in ver 20.6.4.44 without join.

This is my script

select
	'2020-07-15' as dt
from
	recom_stats_dws.load_clk_log_day as tbl
where
	tbl.dt='20200715';

I got error message:

DB::Exception: Unknown identifier: dt there are columns: label (version 20.6.4.44 (official build))

When I rename dt, the script below will run the right way as I expected without error:

select
	'2020-07-15' as rename_dt
from
	recom_stats_dws.load_clk_log_day as tbl
where
	tbl.dt='20200715';