Release v1.0.0

services/packages/common/hotpocket_common/db/postgres.py

@@ -0,0 +1,53 @@
+# -*- coding: utf-8 -*-
+from __future__ import annotations
+
+import typing
+
+from django.db.models.fields import Field
+from django.db.models.lookups import PatternLookup
+
+
+class BaseLikeLookup(PatternLookup):
+    """
+    This class provides base for custom LIKE/ILIKE lookups for PostgreSQL.
+    Unlike the builtin `contains` and `icontains`, these lookups do not do
+    any DB-side processing of parameters. This opens up the ability to use
+    index ops provided by `pg_trgm` to better index text columns for pattern
+    searches.
+
+    These lookups currently support only PostgreSQL 15+.
+    """
+
+    # This is the pattern operator used to generate SQL for the lookup
+    # when the right hand side isn't a raw string. Subclasses must specify this
+    # or the whole thing will blow up ;).
+    PATTERN_OP: str | None = None
+
+    # This is the rhs operator used to generate SQL for the lookup when the
+    # right hand side is a raw string. Subclasses must specify this or the
+    # whole thing will blow up ;).
+    RHS_OP: str | None = None
+
+    def get_rhs_op(self, connection: typing.Any, rhs: typing.Any) -> typing.Any:
+        if hasattr(self.rhs, 'as_sql') or self.bilateral_transforms:
+            pattern = typing.cast(str, self.PATTERN_OP).format(
+                connection.pattern_esc,
+            )
+
+            return pattern.format(rhs)
+        else:
+            return typing.cast(str, self.RHS_OP)
+
+
+@Field.register_lookup
+class Like(BaseLikeLookup):
+    PATTERN_OP = "LIKE '%%' || {} || '%%'"
+    RHS_OP = 'LIKE %s'
+    lookup_name = 'like'
+
+
+@Field.register_lookup
+class ILike(BaseLikeLookup):
+    PATTERN_OP = "ILIKE '%%' || {} || '%%'"
+    RHS_OP = 'ILIKE %s'
+    lookup_name = 'ilike'