# name: test/parquet/parquet_stats_function.test
# description: Test stats(col) function on Parquet files
# group: [parquet]

require parquet

# we can derive whether all values in a parquet column are NULL
statement ok
copy (select null i) to '__TEST_DIR__/all_null.parquet'

# "Has No Null" is "false", meaning there are no non-NULL values
query I
select stats(i) from '__TEST_DIR__/all_null.parquet'
----
[Min: NULL, Max: NULL][Has Null: true, Has No Null: false]

# create 0-9 with no NULL
statement ok
copy (select range i from range(10)) to '__TEST_DIR__/parquet_stats_function1.parquet'

query I
select stats(i) from read_parquet('__TEST_DIR__/parquet_stats_function1.parquet', union_by_name=true) limit 1
----
[Min: 0, Max: 9][Has Null: false, Has No Null: true]

# create 100-109 with NULL
statement ok
copy (select range i from range(100, 110) union all select null i) to '__TEST_DIR__/parquet_stats_function2.parquet'

query I
select stats(i) from read_parquet('__TEST_DIR__/parquet_stats_function2.parquet', union_by_name=true) limit 1
----
[Min: 100, Max: 109][Has Null: true, Has No Null: true]

# query combined WITHOUT union_by_name (should give back no stats)
query I
select stats(i) from read_parquet('__TEST_DIR__/parquet_stats_function*.parquet', union_by_name=false) limit 1
----
[Min: NULL, Max: NULL][Has Null: true, Has No Null: true]

# now query combined WITH union_by_name (should give back stats)
query I
select stats(i) from read_parquet('__TEST_DIR__/parquet_stats_function*.parquet', union_by_name=true) limit 1
----
[Min: 0, Max: 109][Has Null: true, Has No Null: true]