chore: remove deprecated Compiler.compile() wrapper and unused Param class (#17)

* chore: remove deprecated Compiler.compile() wrapper and unused Param class

Remove the deprecated compile() method on Compiler — all callers now
use dialect.compile() directly. Also remove the Param class, its
render method, and the cv_params context variable, as nothing in the
codebase ever instantiates Param.

Closes #7, closes #10

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* chore: remove dead params parameter from BaseDialect.compile()

The params argument was left behind after removing the Param/cv_params
system — it was silently accepted but never used.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: dtsong

data_diff/databases/base.py

@@ -1,5 +1,4 @@
 import abc
-import contextvars
 import decimal
 import functools
 import logging
@@ -65,7 +64,6 @@
     InsertToTable,
     IsDistinctFrom,
     Join,
-    Param,
     Random,
     Root,
     TableAlias,
@@ -81,7 +79,6 @@
 from data_diff.utils import ArithString, ArithUUID, is_uuid, join_iter, safezip
 
 logger = logging.getLogger("database")
-cv_params = contextvars.ContextVar("params")
 
 
 class CompileError(Exception):
@@ -115,10 +112,6 @@ class Compiler(AbstractCompiler):
     def dialect(self) -> "BaseDialect":
         return self.database.dialect
 
-    # TODO: DEPRECATED: Remove once the dialect is used directly in all places.
-    def compile(self, elem, params=None) -> str:
-        return self.dialect.compile(self, elem, params)
-
     def new_unique_name(self, prefix="tmp") -> str:
         self._counter[0] += 1
         return f"{prefix}{self._counter[0]}"
@@ -221,10 +214,7 @@ def parse_table_name(self, name: str) -> DbPath:
         "Parse the given table name into a DbPath"
         return parse_table_name(name)
 
-    def compile(self, compiler: Compiler, elem, params=None) -> str:
-        if params:
-            cv_params.set(params)
-
+    def compile(self, compiler: Compiler, elem) -> str:
         if compiler.root and isinstance(elem, Compilable) and not isinstance(elem, Root):
             from data_diff.queries.ast_classes import Select
 
@@ -268,8 +258,6 @@ def render_compilable(self, c: Compiler, elem: Compilable) -> str:
             return self.render_cte(c, elem)
         elif isinstance(elem, Commit):
             return self.render_commit(c, elem)
-        elif isinstance(elem, Param):
-            return self.render_param(c, elem)
         elif isinstance(elem, NormalizeAsString):
             return self.render_normalizeasstring(c, elem)
         elif isinstance(elem, ApplyFuncAndNormalizeAsString):
@@ -369,10 +357,6 @@ def render_cte(self, parent_c: Compiler, elem: Cte) -> str:
     def render_commit(self, c: Compiler, elem: Commit) -> str:
         return "COMMIT" if not c.database.is_autocommit else SKIP
 
-    def render_param(self, c: Compiler, elem: Param) -> str:
-        params = cv_params.get()
-        return self._compile(c, params[elem.name])
-
     def render_normalizeasstring(self, c: Compiler, elem: NormalizeAsString) -> str:
         expr = self.compile(c, elem.expr)
         return self.normalize_value_by_type(expr, elem.expr_type or elem.expr.type)

data_diff/queries/ast_classes.py

@@ -38,7 +38,7 @@ def _dfs_values(self):
             if k == "source_table":
                 # Skip data-sources, we're only interested in data-parameters
                 continue
-            if not isinstance(vs, (list, tuple)):
+            if not isinstance(vs, list | tuple):
                 vs = [vs]
             for v in vs:
                 if isinstance(v, ExprNode):
@@ -689,7 +689,7 @@ def __getattr__(self, name):
         return _ResolveColumn(name)
 
     def __getitem__(self, name):
-        if isinstance(name, (list, tuple)):
+        if isinstance(name, list | tuple):
             return [_ResolveColumn(n) for n in name]
         return _ResolveColumn(name)
 
@@ -794,10 +794,3 @@ def returning(self, *exprs) -> Self:
 @attrs.define(frozen=True, eq=False)
 class Commit(Statement):
     """Generate a COMMIT statement, if we're in the middle of a transaction, or in auto-commit. Otherwise SKIP."""
-
-
-@attrs.define(frozen=True, eq=False)
-class Param(ExprNode, ITable):  # TODO: Unused?
-    """A value placeholder, to be specified at compilation time using the `cv_params` context variable."""
-
-    name: str

tests/test_query.py

@@ -108,13 +108,13 @@ def test_basic(self):
 
         t = table("point")
         t2 = t.select(x=this.x + 1, y=t["y"] + this.x)
-        assert c.compile(t2) == "SELECT (x + 1) AS x, (y + x) AS y FROM point"
+        assert c.dialect.compile(c, t2) == "SELECT (x + 1) AS x, (y + x) AS y FROM point"
 
         t = table("point").where(this.x == 1, this.y == 2)
-        assert c.compile(t) == "SELECT * FROM point WHERE (x = 1) AND (y = 2)"
+        assert c.dialect.compile(c, t) == "SELECT * FROM point WHERE (x = 1) AND (y = 2)"
 
         t = table("person").where(this.name == "Albert")
-        self.assertEqual(c.compile(t), "SELECT * FROM person WHERE (name = 'Albert')")
+        self.assertEqual(c.dialect.compile(c, t), "SELECT * FROM person WHERE (name = 'Albert')")
 
     def test_outerjoin(self):
         c = Compiler(MockDatabase())
@@ -127,7 +127,8 @@ def test_outerjoin(self):
         j = outerjoin(a, b).on(a[k] == b[k] for k in keys)
 
         self.assertEqual(
-            c.compile(j), "SELECT * FROM a tmp1 FULL OUTER JOIN b tmp2 ON (tmp1.x = tmp2.x) AND (tmp1.y = tmp2.y)"
+            c.dialect.compile(c, j),
+            "SELECT * FROM a tmp1 FULL OUTER JOIN b tmp2 ON (tmp1.x = tmp2.x) AND (tmp1.y = tmp2.y)",
         )
 
     def test_schema(self):
@@ -137,7 +138,7 @@ def test_schema(self):
         # test table
         t = table("a", schema=CaseInsensitiveDict(schema))
         q = t.select(this.Id, t["COMMENT"])
-        assert c.compile(q) == "SELECT id, comment FROM a"
+        assert c.dialect.compile(c, q) == "SELECT id, comment FROM a"
 
         t = table("a", schema=CaseSensitiveDict(schema))
         self.assertRaises(KeyError, t.__getitem__, "Id")
@@ -174,67 +175,67 @@ def test_cte(self):
         t3 = t2.select(this.x)
 
         expected = "WITH tmp1 AS (SELECT x FROM a) SELECT x FROM tmp1"
-        assert normalize_spaces(c.compile(t3)) == expected
+        assert normalize_spaces(c.dialect.compile(c, t3)) == expected
 
         # nested cte
         c = Compiler(MockDatabase())
         t4 = cte(t3).select(this.x)
 
         expected = "WITH tmp1 AS (SELECT x FROM a), tmp2 AS (SELECT x FROM tmp1) SELECT x FROM tmp2"
-        assert normalize_spaces(c.compile(t4)) == expected
+        assert normalize_spaces(c.dialect.compile(c, t4)) == expected
 
         # parameterized cte
         c = Compiler(MockDatabase())
         t2 = cte(t.select(this.x), params=["y"])
         t3 = t2.select(this.y)
 
         expected = "WITH tmp1(y) AS (SELECT x FROM a) SELECT y FROM tmp1"
-        assert normalize_spaces(c.compile(t3)) == expected
+        assert normalize_spaces(c.dialect.compile(c, t3)) == expected
 
     def test_funcs(self):
         c = Compiler(MockDatabase())
         t = table("a")
 
-        q = c.compile(t.order_by(Random()).limit(10))
+        q = c.dialect.compile(c, t.order_by(Random()).limit(10))
         self.assertEqual(q, "SELECT * FROM (SELECT * FROM a ORDER BY random()) AS LIMITED_SELECT LIMIT 10")
 
-        q = c.compile(t.select(coalesce(this.a, this.b)))
+        q = c.dialect.compile(c, t.select(coalesce(this.a, this.b)))
         self.assertEqual(q, "SELECT COALESCE(a, b) FROM a")
 
     def test_select_distinct(self):
         c = Compiler(MockDatabase())
         t = table("a")
 
-        q = c.compile(t.select(this.b, distinct=True))
+        q = c.dialect.compile(c, t.select(this.b, distinct=True))
         assert q == "SELECT DISTINCT b FROM a"
 
         # selects merge
-        q = c.compile(t.where(this.b > 10).select(this.b, distinct=True))
+        q = c.dialect.compile(c, t.where(this.b > 10).select(this.b, distinct=True))
         self.assertEqual(q, "SELECT DISTINCT b FROM a WHERE (b > 10)")
 
         # selects stay apart
-        q = c.compile(t.limit(10).select(this.b, distinct=True))
+        q = c.dialect.compile(c, t.limit(10).select(this.b, distinct=True))
         self.assertEqual(q, "SELECT DISTINCT b FROM (SELECT * FROM (SELECT * FROM a) AS LIMITED_SELECT LIMIT 10) tmp1")
 
-        q = c.compile(t.select(this.b, distinct=True).select(distinct=False))
+        q = c.dialect.compile(c, t.select(this.b, distinct=True).select(distinct=False))
         self.assertEqual(q, "SELECT * FROM (SELECT DISTINCT b FROM a) tmp2")
 
     def test_select_with_optimizer_hints(self):
         c = Compiler(MockDatabase())
         t = table("a")
 
-        q = c.compile(t.select(this.b, optimizer_hints="PARALLEL(a 16)"))
+        q = c.dialect.compile(c, t.select(this.b, optimizer_hints="PARALLEL(a 16)"))
         assert q == "SELECT /*+ PARALLEL(a 16) */ b FROM a"
 
-        q = c.compile(t.where(this.b > 10).select(this.b, optimizer_hints="PARALLEL(a 16)"))
+        q = c.dialect.compile(c, t.where(this.b > 10).select(this.b, optimizer_hints="PARALLEL(a 16)"))
         self.assertEqual(q, "SELECT /*+ PARALLEL(a 16) */ b FROM a WHERE (b > 10)")
 
-        q = c.compile(t.limit(10).select(this.b, optimizer_hints="PARALLEL(a 16)"))
+        q = c.dialect.compile(c, t.limit(10).select(this.b, optimizer_hints="PARALLEL(a 16)"))
         self.assertEqual(
             q, "SELECT /*+ PARALLEL(a 16) */ b FROM (SELECT * FROM (SELECT * FROM a) AS LIMITED_SELECT LIMIT 10) tmp1"
         )
 
-        q = c.compile(t.select(this.a).group_by(this.b).agg(this.c).select(optimizer_hints="PARALLEL(a 16)"))
+        q = c.dialect.compile(c, t.select(this.a).group_by(this.b).agg(this.c).select(optimizer_hints="PARALLEL(a 16)"))
         self.assertEqual(
             q, "SELECT /*+ PARALLEL(a 16) */ * FROM (SELECT b, c FROM (SELECT a FROM a) tmp2 GROUP BY 1) tmp3"
         )
@@ -244,85 +245,86 @@ def test_table_ops(self):
         a = table("a").select(this.x)
         b = table("b").select(this.y)
 
-        q = c.compile(a.union(b))
+        q = c.dialect.compile(c, a.union(b))
         assert q == "SELECT x FROM a UNION SELECT y FROM b"
 
-        q = c.compile(a.union_all(b))
+        q = c.dialect.compile(c, a.union_all(b))
         assert q == "SELECT x FROM a UNION ALL SELECT y FROM b"
 
-        q = c.compile(a.minus(b))
+        q = c.dialect.compile(c, a.minus(b))
         assert q == "SELECT x FROM a EXCEPT SELECT y FROM b"
 
-        q = c.compile(a.intersect(b))
+        q = c.dialect.compile(c, a.intersect(b))
         assert q == "SELECT x FROM a INTERSECT SELECT y FROM b"
 
     def test_ops(self):
         c = Compiler(MockDatabase())
         t = table("a")
 
-        q = c.compile(t.select(this.b + this.c))
+        q = c.dialect.compile(c, t.select(this.b + this.c))
         self.assertEqual(q, "SELECT (b + c) FROM a")
 
-        q = c.compile(t.select(this.b.like(this.c)))
+        q = c.dialect.compile(c, t.select(this.b.like(this.c)))
         self.assertEqual(q, "SELECT (b LIKE c) FROM a")
 
-        q = c.compile(t.select(-this.b.sum()))
+        q = c.dialect.compile(c, t.select(-this.b.sum()))
         self.assertEqual(q, "SELECT (-SUM(b)) FROM a")
 
     def test_group_by(self):
         c = Compiler(MockDatabase())
         t = table("a")
 
-        q = c.compile(t.group_by(this.b).agg(this.c))
+        q = c.dialect.compile(c, t.group_by(this.b).agg(this.c))
         self.assertEqual(q, "SELECT b, c FROM a GROUP BY 1")
 
-        q = c.compile(t.where(this.b > 1).group_by(this.b).agg(this.c))
+        q = c.dialect.compile(c, t.where(this.b > 1).group_by(this.b).agg(this.c))
         self.assertEqual(q, "SELECT b, c FROM a WHERE (b > 1) GROUP BY 1")
 
-        self.assertRaises(CompileError, c.compile, t.select(this.b).group_by(this.b))
+        self.assertRaises(CompileError, c.dialect.compile, c, t.select(this.b).group_by(this.b))
 
-        q = c.compile(t.select(this.b).group_by(this.b).agg())
+        q = c.dialect.compile(c, t.select(this.b).group_by(this.b).agg())
         self.assertEqual(q, "SELECT b FROM (SELECT b FROM a) tmp1 GROUP BY 1")
 
-        q = c.compile(t.group_by(this.b, this.c).agg(this.d, this.e))
+        q = c.dialect.compile(c, t.group_by(this.b, this.c).agg(this.d, this.e))
         self.assertEqual(q, "SELECT b, c, d, e FROM a GROUP BY 1, 2")
 
         # Having
-        q = c.compile(t.group_by(this.b).agg(this.c).having(this.b > 1))
+        q = c.dialect.compile(c, t.group_by(this.b).agg(this.c).having(this.b > 1))
         self.assertEqual(q, "SELECT b, c FROM a GROUP BY 1 HAVING (b > 1)")
 
-        q = c.compile(t.group_by(this.b).having(this.b > 1).agg(this.c))
+        q = c.dialect.compile(c, t.group_by(this.b).having(this.b > 1).agg(this.c))
         self.assertEqual(q, "SELECT b, c FROM a GROUP BY 1 HAVING (b > 1)")
 
-        q = c.compile(t.select(this.b).group_by(this.b).agg().having(this.b > 1))
+        q = c.dialect.compile(c, t.select(this.b).group_by(this.b).agg().having(this.b > 1))
         self.assertEqual(q, "SELECT b FROM (SELECT b FROM a) tmp2 GROUP BY 1 HAVING (b > 1)")
 
         # Having sum
-        q = c.compile(t.group_by(this.b).agg(this.c, this.d).having(this.b.sum() > 1))
+        q = c.dialect.compile(c, t.group_by(this.b).agg(this.c, this.d).having(this.b.sum() > 1))
         self.assertEqual(q, "SELECT b, c, d FROM a GROUP BY 1 HAVING (SUM(b) > 1)")
 
         # Select interaction
-        q = c.compile(t.select(this.a).group_by(this.b).agg(this.c).select(this.c + 1))
+        q = c.dialect.compile(c, t.select(this.a).group_by(this.b).agg(this.c).select(this.c + 1))
         self.assertEqual(q, "SELECT (c + 1) FROM (SELECT b, c FROM (SELECT a FROM a) tmp3 GROUP BY 1) tmp4")
 
     def test_case_when(self):
         c = Compiler(MockDatabase())
         t = table("a")
 
-        q = c.compile(t.select(when(this.b).then(this.c)))
+        q = c.dialect.compile(c, t.select(when(this.b).then(this.c)))
         self.assertEqual(q, "SELECT CASE WHEN b THEN c END FROM a")
 
-        q = c.compile(t.select(when(this.b).then(this.c).else_(this.d)))
+        q = c.dialect.compile(c, t.select(when(this.b).then(this.c).else_(this.d)))
         self.assertEqual(q, "SELECT CASE WHEN b THEN c ELSE d END FROM a")
 
-        q = c.compile(
+        q = c.dialect.compile(
+            c,
             t.select(
                 when(this.type == "text")
                 .then(this.text)
                 .when(this.type == "number")
                 .then(this.number)
                 .else_("unknown type")
-            )
+            ),
         )
         self.assertEqual(
             q,
@@ -333,13 +335,13 @@ def test_code(self):
         c = Compiler(MockDatabase())
         t = table("a")
 
-        q = c.compile(t.select(this.b, code("<x>")).where(code("<y>")))
+        q = c.dialect.compile(c, t.select(this.b, code("<x>")).where(code("<y>")))
         self.assertEqual(q, "SELECT b, <x> FROM a WHERE <y>")
 
         def tablesample(t, size):
             return code("{t} TABLESAMPLE BERNOULLI ({size})", t=t, size=size)
 
         nonzero = table("points").where(this.x > 0, this.y > 0)
 
-        q = c.compile(tablesample(nonzero, 10))
+        q = c.dialect.compile(c, tablesample(nonzero, 10))
         self.assertEqual(q, "SELECT * FROM points WHERE (x > 0) AND (y > 0) TABLESAMPLE BERNOULLI (10)")