sqlglot/tests/test_transforms.py

import unittest

from sqlglot import parse_one
from sqlglot.transforms import (
    eliminate_distinct_on,
    eliminate_qualify,
    remove_precision_parameterized_types,
    unalias_group,
)


class TestTransforms(unittest.TestCase):
    maxDiff = None

    def validate(self, transform, sql, target):
        with self.subTest(sql):
            self.assertEqual(parse_one(sql).transform(transform).sql(), target)

    def test_unalias_group(self):
        self.validate(
            unalias_group,
            "SELECT a, b AS b, c AS c, 4 FROM x GROUP BY a, b, x.c, 4",
            "SELECT a, b AS b, c AS c, 4 FROM x GROUP BY a, 2, x.c, 4",
        )
        self.validate(
            unalias_group,
            "SELECT TO_DATE(the_date) AS the_date, CUSTOM_UDF(other_col) AS other_col, last_col AS aliased_last, COUNT(*) AS the_count FROM x GROUP BY TO_DATE(the_date), CUSTOM_UDF(other_col), aliased_last",
            "SELECT TO_DATE(the_date) AS the_date, CUSTOM_UDF(other_col) AS other_col, last_col AS aliased_last, COUNT(*) AS the_count FROM x GROUP BY TO_DATE(the_date), CUSTOM_UDF(other_col), 3",
        )
        self.validate(
            unalias_group,
            "SELECT SOME_UDF(TO_DATE(the_date)) AS the_date, COUNT(*) AS the_count FROM x GROUP BY SOME_UDF(TO_DATE(the_date))",
            "SELECT SOME_UDF(TO_DATE(the_date)) AS the_date, COUNT(*) AS the_count FROM x GROUP BY SOME_UDF(TO_DATE(the_date))",
        )
        self.validate(
            unalias_group,
            "SELECT SOME_UDF(TO_DATE(the_date)) AS new_date, COUNT(*) AS the_count FROM x GROUP BY new_date",
            "SELECT SOME_UDF(TO_DATE(the_date)) AS new_date, COUNT(*) AS the_count FROM x GROUP BY 1",
        )
        self.validate(
            unalias_group,
            "SELECT the_date AS the_date, COUNT(*) AS the_count FROM x GROUP BY the_date",
            "SELECT the_date AS the_date, COUNT(*) AS the_count FROM x GROUP BY 1",
        )
        self.validate(
            unalias_group,
            "SELECT a AS a FROM x GROUP BY DATE(a)",
            "SELECT a AS a FROM x GROUP BY DATE(a)",
        )

    def test_eliminate_distinct_on(self):
        self.validate(
            eliminate_distinct_on,
            "SELECT DISTINCT ON (a) a, b FROM x ORDER BY c DESC",
            "SELECT a, b FROM (SELECT a, b, ROW_NUMBER() OVER (PARTITION BY a ORDER BY c DESC) AS _row_number FROM x) AS _t WHERE _row_number = 1",
        )
        self.validate(
            eliminate_distinct_on,
            "SELECT DISTINCT ON (a) a, b FROM x",
            "SELECT a, b FROM (SELECT a, b, ROW_NUMBER() OVER (PARTITION BY a ORDER BY a) AS _row_number FROM x) AS _t WHERE _row_number = 1",
        )
        self.validate(
            eliminate_distinct_on,
            "SELECT DISTINCT ON (a, b) a, b FROM x ORDER BY c DESC",
            "SELECT a, b FROM (SELECT a, b, ROW_NUMBER() OVER (PARTITION BY a, b ORDER BY c DESC) AS _row_number FROM x) AS _t WHERE _row_number = 1",
        )
        self.validate(
            eliminate_distinct_on,
            "SELECT DISTINCT a, b FROM x ORDER BY c DESC",
            "SELECT DISTINCT a, b FROM x ORDER BY c DESC",
        )
        self.validate(
            eliminate_distinct_on,
            "SELECT DISTINCT ON (_row_number) _row_number FROM x ORDER BY c DESC",
            "SELECT _row_number FROM (SELECT _row_number, ROW_NUMBER() OVER (PARTITION BY _row_number ORDER BY c DESC) AS _row_number_2 FROM x) AS _t WHERE _row_number_2 = 1",
        )

    def test_eliminate_qualify(self):
        self.validate(
            eliminate_qualify,
            "SELECT i, a + 1 FROM qt QUALIFY ROW_NUMBER() OVER (PARTITION BY p) = 1",
            "SELECT i, _c FROM (SELECT i, a + 1 AS _c, ROW_NUMBER() OVER (PARTITION BY p) AS _w, p FROM qt) AS _t WHERE _w = 1",
        )
        self.validate(
            eliminate_qualify,
            "SELECT i FROM qt QUALIFY ROW_NUMBER() OVER (PARTITION BY p ORDER BY o) = 1 AND p = 0",
            "SELECT i FROM (SELECT i, ROW_NUMBER() OVER (PARTITION BY p ORDER BY o) AS _w, p, o FROM qt) AS _t WHERE _w = 1 AND p = 0",
        )
        self.validate(
            eliminate_qualify,
            "SELECT i, p, o FROM qt QUALIFY ROW_NUMBER() OVER (PARTITION BY p ORDER BY o) = 1",
            "SELECT i, p, o FROM (SELECT i, p, o, ROW_NUMBER() OVER (PARTITION BY p ORDER BY o) AS _w FROM qt) AS _t WHERE _w = 1",
        )
        self.validate(
            eliminate_qualify,
            "SELECT i, p, o, ROW_NUMBER() OVER (PARTITION BY p ORDER BY o) AS row_num FROM qt QUALIFY row_num = 1",
            "SELECT i, p, o, row_num FROM (SELECT i, p, o, ROW_NUMBER() OVER (PARTITION BY p ORDER BY o) AS row_num FROM qt) AS _t WHERE row_num = 1",
        )
        self.validate(
            eliminate_qualify,
            "SELECT * FROM qt QUALIFY ROW_NUMBER() OVER (PARTITION BY p ORDER BY o) = 1",
            "SELECT * FROM (SELECT *, ROW_NUMBER() OVER (PARTITION BY p ORDER BY o) AS _w FROM qt) AS _t WHERE _w = 1",
        )
        self.validate(
            eliminate_qualify,
            "SELECT c2, SUM(c3) OVER (PARTITION BY c2) AS r FROM t1 WHERE c3 < 4 GROUP BY c2, c3 HAVING SUM(c1) > 3 QUALIFY r IN (SELECT MIN(c1) FROM test GROUP BY c2 HAVING MIN(c1) > 3)",
            "SELECT c2, r FROM (SELECT c2, SUM(c3) OVER (PARTITION BY c2) AS r, c1 FROM t1 WHERE c3 < 4 GROUP BY c2, c3 HAVING SUM(c1) > 3) AS _t WHERE r IN (SELECT MIN(c1) FROM test GROUP BY c2 HAVING MIN(c1) > 3)",
        )
        self.validate(
            eliminate_qualify,
            "SELECT x FROM y QUALIFY ROW_NUMBER() OVER (PARTITION BY p)",
            "SELECT x FROM (SELECT x, ROW_NUMBER() OVER (PARTITION BY p) AS _w, p FROM y) AS _t WHERE _w",
        )

    def test_remove_precision_parameterized_types(self):
        self.validate(
            remove_precision_parameterized_types,
            "SELECT CAST(1 AS DECIMAL(10, 2)), CAST('13' AS VARCHAR(10))",
            "SELECT CAST(1 AS DECIMAL), CAST('13' AS VARCHAR)",
        )