refactor(exasol): port to sqlglot (ibis-project#8032)

This PR ports exasol to sqlglot instead of sqlalchemy.

.github/workflows/ibis-backends.yml

@@ -162,13 +162,13 @@ jobs:
           #     - oracle
           #   services:
           #     - oracle
-          # - name: exasol
-          #   title: Exasol
-          #   serial: true
-          #   extras:
-          #     - exasol
-          #   services:
-          #     - exasol
+          - name: exasol
+            title: Exasol
+            serial: true
+            extras:
+              - exasol
+            services:
+              - exasol
           # - name: flink
           #   title: Flink
           #   serial: true
@@ -299,21 +299,21 @@ jobs:
           #       - flink
           # - os: windows-latest
           #   backend:
-          #     name: exasol
-          #     title: Exasol
-          #     serial: true
-          #     extras:
-          #       - exasol
-          #     services:
-          #       - exasol
-          # - os: windows-latest
-          #   backend:
           #     name: risingwave
           #     title: Risingwave
           #     services:
           #       - risingwave
           #     extras:
           #       - risingwave
+          - os: windows-latest
+            backend:
+              name: exasol
+              title: Exasol
+              serial: true
+              extras:
+                - exasol
+              services:
+                - exasol
     steps:
       - name: update and install system dependencies
         if: matrix.os == 'ubuntu-latest' && matrix.backend.sys-deps != null
@@ -612,46 +612,6 @@ jobs:
         with:
           flags: backend,pyspark,${{ runner.os }},python-${{ steps.install_python.outputs.python-version }}
 
-  # gen_lockfile_sqlalchemy2:
-  #   name: Generate Poetry Lockfile for SQLAlchemy 2
-  #   runs-on: ubuntu-latest
-  #   steps:
-  #     - name: checkout
-  #       uses: actions/checkout@v4
-  #
-  #     - name: install python
-  #       uses: actions/setup-python@v5
-  #       with:
-  #         python-version: "3.11"
-  #
-  #     - run: python -m pip install --upgrade pip 'poetry==1.7.1'
-  #
-  #     - name: remove deps that are not compatible with sqlalchemy 2
-  #       run: poetry remove sqlalchemy-exasol
-  #
-  #     - name: add sqlalchemy 2
-  #       run: poetry add --lock --optional 'sqlalchemy>=2,<3'
-  #
-  #     - name: checkout the lock file
-  #       run: git checkout poetry.lock
-  #
-  #     - name: lock with no updates
-  #       # poetry add is aggressive and will update other dependencies like
-  #       # numpy and pandas so we keep the pyproject.toml edits and then relock
-  #       # without updating anything except the requested versions
-  #       run: poetry lock --no-update
-  #
-  #     - name: check the sqlalchemy version
-  #       run: poetry show sqlalchemy --no-ansi | grep version | cut -d ':' -f2- | sed 's/ //g' | grep -P '^2\.'
-  #
-  #     - name: upload deps file
-  #       uses: actions/upload-artifact@v3
-  #       with:
-  #         name: deps
-  #         path: |
-  #           pyproject.toml
-  #           poetry.lock
-
   # test_backends_sqlalchemy2:
   #   name: SQLAlchemy 2 ${{ matrix.backend.title }} ${{ matrix.os }} python-${{ matrix.python-version }}
   #   runs-on: ${{ matrix.os }}

ci/schema/exasol.sql

@@ -1,7 +1,7 @@
 DROP SCHEMA IF EXISTS EXASOL CASCADE;
 CREATE SCHEMA EXASOL;
 
-CREATE OR REPLACE TABLE EXASOL.diamonds
+CREATE OR REPLACE TABLE EXASOL."diamonds"
 (
     "carat"   DOUBLE,
     "cut"     VARCHAR(256),
@@ -15,13 +15,13 @@ CREATE OR REPLACE TABLE EXASOL.diamonds
     "z"       DOUBLE
 );
 
-CREATE OR REPLACE TABLE EXASOL.batting
+CREATE OR REPLACE TABLE EXASOL."batting"
 (
     "playerID" VARCHAR(256),
     "yearID"   BIGINT,
     "stint"    BIGINT,
     "teamID"   VARCHAR(256),
-    "logID"    VARCHAR(256),
+    "lgID"     VARCHAR(256),
     "G"        BIGINT,
     "AB"       BIGINT,
     "R"        BIGINT,
@@ -41,22 +41,22 @@ CREATE OR REPLACE TABLE EXASOL.batting
     "GIDP"     BIGINT
 );
 
-CREATE OR REPLACE TABLE EXASOL.awards_players
+CREATE OR REPLACE TABLE EXASOL."awards_players"
 (
-    "playerId" VARCHAR(256),
+    "playerID" VARCHAR(256),
     "awardID"  VARCHAR(256),
-    "yearID"   VARCHAR(256),
-    "logID"    VARCHAR(256),
+    "yearID"   BIGINT,
+    "lgID"     VARCHAR(256),
     "tie"      VARCHAR(256),
     "notest"   VARCHAR(256)
 );
 
-CREATE OR REPLACE TABLE EXASOL.functional_alltypes
+CREATE OR REPLACE TABLE EXASOL."functional_alltypes"
 (
     "id"              INTEGER,
     "bool_col"        BOOLEAN,
     "tinyint_col"     SHORTINT,
-    "small_int"       SMALLINT,
+    "smallint_col"    SMALLINT,
     "int_col"         INTEGER,
     "bigint_col"      BIGINT,
     "float_col"       FLOAT,
@@ -69,7 +69,21 @@ CREATE OR REPLACE TABLE EXASOL.functional_alltypes
 );
 
 
-IMPORT INTO EXASOL.diamonds FROM LOCAL CSV FILE '/data/diamonds.csv' COLUMN SEPARATOR = ',' SKIP = 1;
-IMPORT INTO EXASOL.batting FROM LOCAL CSV FILE '/data/batting.csv' COLUMN SEPARATOR = ',' SKIP = 1;
-IMPORT INTO EXASOL.awards_players FROM LOCAL CSV FILE '/data/awards_players.csv' COLUMN SEPARATOR = ',' SKIP = 1;
-IMPORT INTO EXASOL.functional_alltypes FROM LOCAL CSV FILE '/data/functional_alltypes.csv' COLUMN SEPARATOR = ',' SKIP = 1;
+IMPORT INTO EXASOL."diamonds" FROM LOCAL CSV FILE '/data/diamonds.csv' COLUMN SEPARATOR = ',' SKIP = 1;
+IMPORT INTO EXASOL."batting" FROM LOCAL CSV FILE '/data/batting.csv' COLUMN SEPARATOR = ',' SKIP = 1;
+IMPORT INTO EXASOL."awards_players" FROM LOCAL CSV FILE '/data/awards_players.csv' COLUMN SEPARATOR = ',' SKIP = 1;
+IMPORT INTO EXASOL."functional_alltypes" FROM LOCAL CSV FILE '/data/functional_alltypes.csv' COLUMN SEPARATOR = ',' SKIP = 1;
+
+CREATE OR REPLACE TABLE EXASOL."win"
+(
+    "g" VARCHAR(1),
+    "x" BIGINT,
+    "y" BIGINT
+);
+
+INSERT INTO "win" VALUES
+    ('a', 0, 3),
+    ('a', 1, 2),
+    ('a', 2, 0),
+    ('a', 3, 1),
+    ('a', 4, 1);

ibis/backends/base/sqlglot/datatypes.py

@@ -738,3 +738,79 @@ def _from_ibis_Int64(cls, dtype: dt.Int64) -> NoReturn:
         raise com.UnsupportedBackendType(
             "int64 is not a supported input or output type in BigQuery UDFs; use float64 instead"
         )
+
+
+class ExasolType(SqlglotType):
+    dialect = "exasol"
+
+    default_temporal_scale = 3
+
+    default_decimal_precision = 18
+    default_decimal_scale = 0
+
+    @classmethod
+    def _from_ibis_String(cls, dtype: dt.String) -> sge.DataType:
+        return sge.DataType(
+            this=sge.DataType.Type.VARCHAR,
+            expressions=[sge.DataTypeParam(this=sge.convert(2_000_000))],
+        )
+
+    @classmethod
+    def _from_sqlglot_DECIMAL(
+        cls,
+        precision: sge.DataTypeParam | None = None,
+        scale: sge.DataTypeParam | None = None,
+    ) -> dt.Decimal:
+        if precision is None:
+            precision = cls.default_decimal_precision
+        else:
+            precision = int(precision.this.this)
+
+        if scale is None:
+            scale = cls.default_decimal_scale
+        else:
+            scale = int(scale.this.this)
+
+        if not scale:
+            if 0 < precision <= 3:
+                return dt.Int8(nullable=cls.default_nullable)
+            elif 3 < precision <= 9:
+                return dt.Int16(nullable=cls.default_nullable)
+            elif 9 < precision <= 18:
+                return dt.Int32(nullable=cls.default_nullable)
+            elif 18 < precision <= 36:
+                return dt.Int64(nullable=cls.default_nullable)
+            else:
+                raise com.UnsupportedBackendType(
+                    "Decimal precision is too large; Exasol supports precision up to 36."
+                )
+        return dt.Decimal(precision, scale, nullable=cls.default_nullable)
+
+    @classmethod
+    def _from_ibis_Array(cls, dtype: dt.Array) -> NoReturn:
+        raise com.UnsupportedBackendType("Arrays not supported in Exasol")
+
+    @classmethod
+    def _from_ibis_Map(cls, dtype: dt.Map) -> NoReturn:
+        raise com.UnsupportedBackendType("Maps not supported in Exasol")
+
+    @classmethod
+    def _from_ibis_Struct(cls, dtype: dt.Struct) -> NoReturn:
+        raise com.UnsupportedBackendType("Structs not supported in Exasol")
+
+    @classmethod
+    def _from_ibis_Timestamp(cls, dtype: dt.Timestamp) -> sge.DataType:
+        code = typecode.TIMESTAMP if dtype.timezone is None else typecode.TIMESTAMPTZ
+        return sge.DataType(this=code)
+
+    @classmethod
+    def _from_sqlglot_ARRAY(cls, value_type: sge.DataType) -> NoReturn:
+        raise com.UnsupportedBackendType("Arrays not supported in Exasol")
+
+    @classmethod
+    def _from_sqlglot_MAP(cls, key: sge.DataType, value: sge.DataType) -> NoReturn:
+        raise com.UnsupportedBackendType("Maps not supported in Exasol")
+
+    @classmethod
+    def _from_sqlglot_STRUCT(cls, *cols: sge.ColumnDef) -> NoReturn:
+        raise com.UnsupportedBackendType("Structs not supported in Exasol")

ibis/backends/conftest.py

@@ -548,7 +548,6 @@ def ddl_con(ddl_backend):
 @pytest.fixture(
     params=_get_backends_to_test(
         keep=(
-            "exasol",
             "mssql",
             "oracle",
             "risingwave",