Core: Improve TableAddress.fullname

By making the canonical `DatabaseAdapter.quote_relation_name` static, 
it can be used by `TableAddress.fullname` now.

This makes table name quoting less fragmented across the code base.

cratedb_toolkit/model.py

@@ -4,7 +4,7 @@
 
 from boltons.urlutils import URL
 
-from cratedb_toolkit.util.database import decode_database_table
+from cratedb_toolkit.util.database import DatabaseAdapter, decode_database_table
 
 
 @dataclasses.dataclass
@@ -85,12 +85,10 @@ class TableAddress:
 
     @property
     def fullname(self):
-        if self.schema is None and self.table is None:
-            raise ValueError("Uninitialized table address can not be serialized")
-        if self.schema and self.table:
-            return f'"{self.schema}"."{self.table}"'
-        else:
-            return f'"{self.table}"'
+        """
+        Return a full-qualified quoted table identifier.
+        """
+        return DatabaseAdapter.quote_relation_name(f"{self.schema}.{self.table}")
 
 
 @dataclasses.dataclass

cratedb_toolkit/util/database.py

@@ -11,6 +11,7 @@
 from cratedb_sqlparse import sqlparse as sqlparse_cratedb
 from sqlalchemy.exc import ProgrammingError
 from sqlalchemy.sql.elements import AsBoolean
+from sqlalchemy_cratedb.dialect import CrateDialect
 
 from cratedb_toolkit.util.data import str_contains
 
@@ -24,6 +25,10 @@ def run_sql(dburi: str, sql: str, records: bool = False):
     return DatabaseAdapter(dburi=dburi).run_sql(sql=sql, records=records)
 
 
+# Just an instance of the dialect used for quoting purposes.
+dialect = CrateDialect()
+
+
 class DatabaseAdapter:
     """
     Wrap SQLAlchemy connection to database.
@@ -35,37 +40,43 @@ def __init__(self, dburi: str, echo: bool = False):
         # TODO: Make that go away.
         self.connection = self.engine.connect()
 
-    def quote_relation_name(self, ident: str) -> str:
+    @staticmethod
+    def quote_relation_name(ident: str) -> str:
         """
-        Quote the given, possibly full-qualified, relation name if needed.
+        Quote a simple or full-qualified table/relation name, when needed.
 
-        In:  foo
-        Out: foo
+        Simple:         <table>
+        Full-qualified: <schema>.<table>
 
-        In:  Foo
-        Out: "Foo"
+        Happy path examples:
 
-        In:  "Foo"
-        Out: "Foo"
+            foo => foo
+            Foo => "Foo"
+            "Foo" => "Foo"
+            foo.bar => foo.bar
+            foo-bar.baz_qux => "foo-bar".baz_qux
 
-        In:  foo.bar
-        Out: "foo"."bar"
+        Such input strings will not be modified:
 
-        In:  "foo.bar"
-        Out: "foo.bar"
+            "foo.bar" => "foo.bar"
         """
-        if ident[0] == '"' and ident[len(ident) - 1] == '"':
+
+        # Heuristically consider that if a quote exists at the beginning or the end
+        # of the input string, that the relation name has been quoted already.
+        if ident.startswith('"') or ident.endswith('"'):
             return ident
+
+        # Heuristically consider if a dot is included, that it's a full-qualified
+        # identifier like <schema>.<table>. It needs to be split, in order to apply
+        # identifier quoting properly.
         if "." in ident:
             parts = ident.split(".")
             if len(parts) > 2:
                 raise ValueError(f"Invalid relation name {ident}")
             return (
-                self.engine.dialect.identifier_preparer.quote_schema(parts[0])
-                + "."
-                + self.engine.dialect.identifier_preparer.quote(parts[1])
+                dialect.identifier_preparer.quote_schema(parts[0]) + "." + dialect.identifier_preparer.quote(parts[1])
             )
-        return self.engine.dialect.identifier_preparer.quote(ident=ident)
+        return dialect.identifier_preparer.quote(ident=ident)
 
     def run_sql(
         self,

tests/util/database.py

@@ -3,7 +3,10 @@
 from cratedb_toolkit.util import DatabaseAdapter
 
 
-def test_quote_relation_name():
+def test_quote_relation_name_single():
+    """
+    Verify quoting a simple or full-qualified relation name.
+    """
     database = DatabaseAdapter(dburi="crate://localhost")
     assert database.quote_relation_name("my_table") == "my_table"
     assert database.quote_relation_name("my-table") == '"my-table"'
@@ -17,6 +20,17 @@ def test_quote_relation_name():
     assert database.quote_relation_name("table") == '"table"'
 
 
+def test_quote_relation_name_double():
+    """
+    Verify quoting a relation name twice does not cause any harm.
+    """
+    database = DatabaseAdapter(dburi="crate://localhost")
+    input_fqn = "foo-bar.baz_qux"
+    output_fqn = '"foo-bar".baz_qux'
+    assert database.quote_relation_name(input_fqn) == output_fqn
+    assert database.quote_relation_name(output_fqn) == output_fqn
+
+
 def test_quote_relation_name_with_invalid_fqn():
     database = DatabaseAdapter(dburi="crate://localhost")
     with pytest.raises(ValueError):