Implement fetchmany

.changes/unreleased/Fixes-20230809-162435.yaml

@@ -0,0 +1,7 @@
+kind: Fixes
+body: Implemented fetchmany
+time: 2023-08-09T16:24:35.116089+02:00
+custom:
+  Author: damian3031
+  Issue: ""
+  PR: "341"

dbt/adapters/trino/connections.py

@@ -331,6 +331,17 @@ def fetchone(self):
 
         return None
 
+    def fetchmany(self, size):
+        if self._cursor is None:
+            return None
+
+        if self._fetch_result is not None:
+            ret = self._fetch_result[:size]
+            self._fetch_result = None
+            return ret
+
+        return None
+
     def execute(self, sql, bindings=None):
         if not self._prepared_statements_enabled and bindings is not None:
             # DEPRECATED: by default prepared statements are used.

tests/functional/adapter/show/fixtures.py

@@ -0,0 +1,84 @@
+models__sample_model = """
+select * from {{ ref('sample_seed') }}
+"""
+
+models__second_model = """
+select
+    sample_num as col_one,
+    sample_bool as col_two,
+    42 as answer
+from {{ ref('sample_model') }}
+"""
+
+models__sql_header = """
+{% call set_sql_header(config) %}
+set time zone 'Asia/Kolkata';
+{%- endcall %}
+select current_timezone() as timezone
+"""
+
+private_model_yml = """
+groups:
+  - name: my_cool_group
+    owner: {name: me}
+
+models:
+  - name: private_model
+    access: private
+    config:
+      group: my_cool_group
+"""
+
+
+schema_yml = """
+models:
+  - name: sample_model
+    latest_version: 1
+
+    # declare the versions, and fully specify them
+    versions:
+      - v: 2
+        config:
+          materialized: table
+        columns:
+          - name: sample_num
+            data_type: int
+          - name: sample_bool
+            data_type: boolean
+          - name: answer
+            data_type: int
+
+      - v: 1
+        config:
+          materialized: table
+          contract: {enforced: true}
+        columns:
+          - name: sample_num
+            data_type: int
+          - name: sample_bool
+            data_type: boolean
+"""
+
+models__ephemeral_model = """
+{{ config(materialized = 'ephemeral') }}
+select
+    coalesce(sample_num, 0) + 10 as col_deci
+from {{ ref('sample_model') }}
+"""
+
+models__second_ephemeral_model = """
+{{ config(materialized = 'ephemeral') }}
+select
+    col_deci + 100 as col_hundo
+from {{ ref('ephemeral_model') }}
+"""
+
+seeds__sample_seed = """sample_num,sample_bool
+1,true
+2,false
+3,true
+4,false
+5,true
+6,false
+7,true
+"""

tests/functional/adapter/show/test_show.py

@@ -0,0 +1,160 @@
+import pytest
+from dbt.exceptions import DbtRuntimeError
+from dbt.exceptions import Exception as DbtException
+from dbt.tests.util import run_dbt, run_dbt_and_capture
+
+from tests.functional.adapter.show.fixtures import (
+    models__ephemeral_model,
+    models__sample_model,
+    models__second_ephemeral_model,
+    models__second_model,
+    models__sql_header,
+    private_model_yml,
+    schema_yml,
+    seeds__sample_seed,
+)
+
+
+class TestShow:
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {
+            "sample_model.sql": models__sample_model,
+            "second_model.sql": models__second_model,
+            "ephemeral_model.sql": models__ephemeral_model,
+            "sql_header.sql": models__sql_header,
+        }
+
+    @pytest.fixture(scope="class")
+    def seeds(self):
+        return {"sample_seed.csv": seeds__sample_seed}
+
+    def test_none(self, project):
+        with pytest.raises(
+            DbtRuntimeError, match="Either --select or --inline must be passed to show"
+        ):
+            run_dbt(["seed"])
+            run_dbt(["show"])
+
+    def test_select_model_text(self, project):
+        run_dbt(["build"])
+        (results, log_output) = run_dbt_and_capture(["show", "--select", "second_model"])
+        assert "Previewing node 'sample_model'" not in log_output
+        assert "Previewing node 'second_model'" in log_output
+        assert "col_one" in log_output
+        assert "col_two" in log_output
+        assert "answer" in log_output
+
+    def test_select_multiple_model_text(self, project):
+        run_dbt(["build"])
+        (results, log_output) = run_dbt_and_capture(
+            ["show", "--select", "sample_model second_model"]
+        )
+        assert "Previewing node 'sample_model'" in log_output
+        assert "sample_num" in log_output
+        assert "sample_bool" in log_output
+
+    def test_select_single_model_json(self, project):
+        run_dbt(["build"])
+        (results, log_output) = run_dbt_and_capture(
+            ["show", "--select", "sample_model", "--output", "json"]
+        )
+        assert "Previewing node 'sample_model'" not in log_output
+        assert "sample_num" in log_output
+        assert "sample_bool" in log_output
+
+    def test_inline_pass(self, project):
+        run_dbt(["build"])
+        (results, log_output) = run_dbt_and_capture(
+            ["show", "--inline", "select * from {{ ref('sample_model') }}"]
+        )
+        assert "Previewing inline node" in log_output
+        assert "sample_num" in log_output
+        assert "sample_bool" in log_output
+
+    def test_inline_fail(self, project):
+        with pytest.raises(DbtException, match="Error parsing inline query"):
+            run_dbt(["show", "--inline", "select * from {{ ref('third_model') }}"])
+
+    def test_inline_fail_database_error(self, project):
+        with pytest.raises(DbtRuntimeError, match="Database Error"):
+            run_dbt(["show", "--inline", "slect asdlkjfsld;j"])
+
+    def test_ephemeral_model(self, project):
+        run_dbt(["build"])
+        (results, log_output) = run_dbt_and_capture(["show", "--select", "ephemeral_model"])
+        assert "col_deci" in log_output
+
+    def test_second_ephemeral_model(self, project):
+        run_dbt(["build"])
+        (results, log_output) = run_dbt_and_capture(
+            ["show", "--inline", models__second_ephemeral_model]
+        )
+        assert "col_hundo" in log_output
+
+    # test_limit tests ConnectionWrapper.fetchmany()
+    @pytest.mark.parametrize(
+        "args,expected",
+        [
+            ([], 5),  # default limit
+            (["--limit", 3], 3),  # fetch 3 rows
+            (["--limit", -1], 7),  # fetch all rows
+        ],
+    )
+    def test_limit(self, project, args, expected):
+        run_dbt(["build"])
+        dbt_args = ["show", "--inline", models__second_ephemeral_model, *args]
+        results, log_output = run_dbt_and_capture(dbt_args)
+        assert len(results.results[0].agate_table) == expected
+
+    def test_seed(self, project):
+        (results, log_output) = run_dbt_and_capture(["show", "--select", "sample_seed"])
+        assert "Previewing node 'sample_seed'" in log_output
+
+    def test_sql_header(self, project):
+        run_dbt(["build"])
+        (results, log_output) = run_dbt_and_capture(["show", "--select", "sql_header"])
+        assert "Asia/Kolkata" in log_output
+
+
+class TestShowModelVersions:
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {
+            "schema.yml": schema_yml,
+            "sample_model.sql": models__sample_model,
+            "sample_model_v2.sql": models__second_model,
+        }
+
+    @pytest.fixture(scope="class")
+    def seeds(self):
+        return {"sample_seed.csv": seeds__sample_seed}
+
+    def test_version_unspecified(self, project):
+        run_dbt(["build"])
+        (results, log_output) = run_dbt_and_capture(["show", "--select", "sample_model"])
+        assert "Previewing node 'sample_model.v1'" in log_output
+        assert "Previewing node 'sample_model.v2'" in log_output
+
+    def test_none(self, project):
+        run_dbt(["build"])
+        (results, log_output) = run_dbt_and_capture(["show", "--select", "sample_model.v2"])
+        assert "Previewing node 'sample_model.v1'" not in log_output
+        assert "Previewing node 'sample_model.v2'" in log_output
+
+
+class TestShowPrivateModel:
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {
+            "schema.yml": private_model_yml,
+            "private_model.sql": models__sample_model,
+        }
+
+    @pytest.fixture(scope="class")
+    def seeds(self):
+        return {"sample_seed.csv": seeds__sample_seed}
+
+    def test_version_unspecified(self, project):
+        run_dbt(["build"])
+        run_dbt(["show", "--inline", "select * from {{ ref('private_model') }}"])