feat: Docker Compose local test infrastructure with seed data

.github/workflows/ci.yml

@@ -42,7 +42,8 @@ jobs:
         run: uv tool run ty check --python-version 3.10
 
       - name: Build the stack
-        run: docker compose up -d --wait mysql postgres presto trino clickhouse
+        # --profile full unlocks profile-gated clickhouse; only named services start
+        run: docker compose --profile full up -d --wait mysql postgres clickhouse
 
       - name: Run tests
         env:

Makefile

@@ -0,0 +1,45 @@
+.PHONY: up up-full down test-unit test demo
+
+## Start PostgreSQL + MySQL (lightweight, fast startup)
+up:
+	docker compose up -d --wait postgres mysql
+
+## Start all services including ClickHouse, Presto, Trino, Vertica
+up-full:
+	docker compose --profile full up -d --wait
+
+## Stop all services and remove volumes
+down:
+	docker compose --profile full down -v
+
+## Run unit tests (no database required)
+test-unit:
+	uv run pytest tests/test_query.py tests/test_utils.py -x
+
+## Run full test suite against PG + MySQL (starts containers if needed)
+## To also test Presto/Trino/Vertica, run `make up-full` first and set:
+##   export DATADIFF_PRESTO_URI="presto://test@localhost:8080/memory/default"
+##   export DATADIFF_TRINO_URI="trino://test@localhost:8081/memory/default"
+##   export DATADIFF_VERTICA_URI="vertica://vertica:Password1@localhost:5433/vertica"
+test: up
+	uv run pytest tests/ \
+		-o addopts="--timeout=300 --tb=short" \
+		--ignore=tests/test_database_types.py \
+		--ignore=tests/test_dbt_config_validators.py \
+		--ignore=tests/test_main.py
+
+## Run data-diff against seed data to showcase diffing
+demo: up
+	@echo "=== PostgreSQL: ratings_source vs ratings_target ==="
+	uv run python -m data_diff \
+		postgresql://postgres:Password1@localhost/postgres \
+		ratings_source ratings_target \
+		--key-columns id \
+		--columns rating
+	@echo ""
+	@echo "=== MySQL: ratings_source vs ratings_target ==="
+	uv run python -m data_diff \
+		mysql://mysql:Password1@localhost/mysql \
+		ratings_source ratings_target \
+		--key-columns id \
+		--columns rating

data_diff/databases/postgresql.py

@@ -25,7 +25,6 @@
     CHECKSUM_HEXDIGITS,
     CHECKSUM_OFFSET,
     MD5_HEXDIGITS,
-    TIMESTAMP_PRECISION_POS,
     BaseDialect,
     ConnectError,
     ThreadedDatabase,
@@ -115,8 +114,14 @@ def md5_as_hex(self, s: str) -> str:
         return f"md5({s})"
 
     def normalize_timestamp(self, value: str, coltype: TemporalType) -> str:
-        def _add_padding(coltype: TemporalType, timestamp6: str):
-            return f"RPAD(LEFT({timestamp6}, {TIMESTAMP_PRECISION_POS + coltype.precision}), {TIMESTAMP_PRECISION_POS + 6}, '0')"
+        def _truncate_and_pad(coltype: TemporalType, timestamp6: str):
+            """Truncate a 6-digit-precision timestamp to target precision, then zero-pad back to 6 digits."""
+            truncated = f"LEFT({timestamp6}, length({timestamp6}) - (6 - {coltype.precision}))"
+            return f"RPAD({truncated}, length({timestamp6}), '0')"
+
+        def _zero_pad(coltype: TemporalType, already_truncated: str):
+            """Zero-pad an already-truncated timestamp back to 6 fractional digits."""
+            return f"RPAD({already_truncated}, length({already_truncated}) + (6 - {coltype.precision}), '0')"
 
         try:
             is_date = coltype.is_date
@@ -141,30 +146,28 @@ def _add_padding(coltype: TemporalType, timestamp6: str):
             null_case_end = "END"
 
             # 294277 or 4714 BC would be out of range, make sure we can't round to that
-            # TODO test timezones for overflow?
             max_timestamp = "294276-12-31 23:59:59.0000"
             min_timestamp = "4713-01-01 00:00:00.00 BC"
-            timestamp = f"least('{max_timestamp}'::timestamp(6), {value}::timestamp(6))"
-            timestamp = f"greatest('{min_timestamp}'::timestamp(6), {timestamp})"
+            ts_type = "timestamptz(6)" if isinstance(coltype, TimestampTZ) else "timestamp(6)"
+            timestamp = f"least('{max_timestamp}'::{ts_type}, {value}::{ts_type})"
+            timestamp = f"greatest('{min_timestamp}'::{ts_type}, {timestamp})"
 
             interval = format((0.5 * (10 ** (-coltype.precision))), f".{coltype.precision + 1}f")
 
             rounded_timestamp = (
-                f"left(to_char(least('{max_timestamp}'::timestamp, {timestamp})"
+                f"left(to_char(least('{max_timestamp}'::{ts_type}, {timestamp})"
                 f"+ interval '{interval}', 'YYYY-mm-dd HH24:MI:SS.US'),"
-                f"length(to_char(least('{max_timestamp}'::timestamp, {timestamp})"
+                f"length(to_char(least('{max_timestamp}'::{ts_type}, {timestamp})"
                 f"+ interval '{interval}', 'YYYY-mm-dd HH24:MI:SS.US')) - (6-{coltype.precision}))"
             )
 
-            padded = _add_padding(coltype, rounded_timestamp)
+            padded = _zero_pad(coltype, rounded_timestamp)
             return f"{null_case_begin} {padded} {null_case_end}"
 
-            # TODO years with > 4 digits not padded correctly
-            # current w/ precision 6: 294276-12-31 23:59:59.0000
-            # should be 294276-12-31 23:59:59.000000
         else:
-            rounded_timestamp = f"to_char({value}::timestamp(6), 'YYYY-mm-dd HH24:MI:SS.US')"
-            padded = _add_padding(coltype, rounded_timestamp)
+            ts_type = "timestamptz(6)" if isinstance(coltype, TimestampTZ) else "timestamp(6)"
+            rounded_timestamp = f"to_char({value}::{ts_type}, 'YYYY-mm-dd HH24:MI:SS.US')"
+            padded = _truncate_and_pad(coltype, rounded_timestamp)
             return padded
 
     def normalize_number(self, value: str, coltype: FractionalType) -> str:

data_diff/queries/ast_classes.py

@@ -483,7 +483,8 @@ class Join(ExprNode, ITable, Root):
     def schema(self) -> Schema:
         if not self.columns:
             raise ValueError("Join must specify columns explicitly (SELECT * not yet implemented).")
-        s = self.source_tables[0].schema  # TODO validate types match between both tables
+        # No cross-table type validation needed: join combines columns from both tables rather than unioning rows
+        s = self.source_tables[0].schema
         return type(s)({c.name: c.type for c in self.columns})
 
     def on(self, *exprs) -> Self:
@@ -553,15 +554,28 @@ class TableOp(ExprNode, ITable, Root):
 
     @property
     def type(self):
-        # TODO ensure types of both tables are compatible
-        return self.table1.type
+        t1 = self.table1.type
+        t2 = self.table2.type
+        if t1 is None or t2 is None:
+            return None
+        if type(t1) is not type(t2):
+            raise QueryBuilderError(f"Type mismatch in {self.op}: got {type(t1).__name__} and {type(t2).__name__}")
+        return t1
 
     @property
     def schema(self) -> Schema:
         s1 = self.table1.schema
         s2 = self.table2.schema
+        if s1 is None or s2 is None:
+            raise QueryBuilderError(f"Cannot validate {self.op}: one or both tables have no schema defined")
         if len(s1) != len(s2):
-            raise ValueError(f"TableOp requires tables with matching schema lengths, got {len(s1)} and {len(s2)}.")
+            raise QueryBuilderError(f"Schema length mismatch in {self.op}: got {len(s1)} and {len(s2)} columns")
+        for (name1, type1), (name2, type2) in zip(s1.items(), s2.items()):
+            if type(type1) is not type(type2):
+                raise QueryBuilderError(
+                    f"Type mismatch in {self.op}: column {name1!r} is {type(type1).__name__} "
+                    f"but column {name2!r} is {type(type2).__name__}"
+                )
         return s1
 
 

dev/seed/mysql/01_seed.sql

@@ -0,0 +1,59 @@
+-- Seed data for demonstrating data-diff capabilities.
+-- Auto-executed by MySQL on first container startup.
+
+CREATE TABLE ratings_source (
+    id         INT PRIMARY KEY,
+    user_id    INT NOT NULL,
+    movie_id   INT NOT NULL,
+    rating     DECIMAL(2,1) NOT NULL,
+    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE TABLE ratings_target (
+    id         INT PRIMARY KEY,
+    user_id    INT NOT NULL,
+    movie_id   INT NOT NULL,
+    rating     DECIMAL(2,1) NOT NULL,
+    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+-- Populate source with 1000 rows via stored procedure (MySQL lacks generate_series)
+DELIMITER //
+CREATE PROCEDURE seed_ratings()
+BEGIN
+    DECLARE i INT DEFAULT 1;
+    WHILE i <= 1000 DO
+        INSERT INTO ratings_source (id, user_id, movie_id, rating, created_at)
+        VALUES (
+            i,
+            1 + (i % 200),
+            1 + (i % 50),
+            1 + (i % 5),
+            DATE_ADD('2025-01-01', INTERVAL i MINUTE)
+        );
+        SET i = i + 1;
+    END WHILE;
+END //
+DELIMITER ;
+
+CALL seed_ratings();
+DROP PROCEDURE seed_ratings;
+
+-- Copy all rows into target
+INSERT INTO ratings_target SELECT * FROM ratings_source;
+
+-- Introduce diffs:
+-- 5 deleted rows (IDs 10-14 missing from target)
+DELETE FROM ratings_target WHERE id BETWEEN 10 AND 14;
+
+-- 5 extra rows in target only (IDs 1001-1005)
+INSERT INTO ratings_target (id, user_id, movie_id, rating, created_at) VALUES
+    (1001, 201, 51, 4.0, '2025-06-01 00:00:00'),
+    (1002, 202, 52, 3.0, '2025-06-02 00:00:00'),
+    (1003, 203, 53, 5.0, '2025-06-03 00:00:00'),
+    (1004, 204, 54, 2.0, '2025-06-04 00:00:00'),
+    (1005, 205, 55, 1.0, '2025-06-05 00:00:00');
+
+-- 10 updated ratings (IDs 100-109 have different ratings in target)
+UPDATE ratings_target SET rating = rating + 0.5 WHERE id BETWEEN 100 AND 109 AND rating < 5.0;
+UPDATE ratings_target SET rating = 1.0             WHERE id BETWEEN 100 AND 109 AND rating >= 5.0;

dev/seed/postgres/01_seed.sql

@@ -0,0 +1,47 @@
+-- Seed data for demonstrating data-diff capabilities.
+-- Auto-executed by PostgreSQL on first container startup.
+
+CREATE TABLE ratings_source (
+    id         INTEGER PRIMARY KEY,
+    user_id    INTEGER NOT NULL,
+    movie_id   INTEGER NOT NULL,
+    rating     NUMERIC(2,1) NOT NULL,
+    created_at TIMESTAMP NOT NULL DEFAULT now()
+);
+
+CREATE TABLE ratings_target (
+    id         INTEGER PRIMARY KEY,
+    user_id    INTEGER NOT NULL,
+    movie_id   INTEGER NOT NULL,
+    rating     NUMERIC(2,1) NOT NULL,
+    created_at TIMESTAMP NOT NULL DEFAULT now()
+);
+
+-- Populate source with 1000 rows
+INSERT INTO ratings_source (id, user_id, movie_id, rating, created_at)
+SELECT
+    g                                    AS id,
+    1 + (g % 200)                        AS user_id,
+    1 + (g % 50)                         AS movie_id,
+    (1 + (g % 5))::NUMERIC(2,1)         AS rating,
+    '2025-01-01'::TIMESTAMP + (g || ' minutes')::INTERVAL AS created_at
+FROM generate_series(1, 1000) AS g;
+
+-- Copy all rows into target
+INSERT INTO ratings_target SELECT * FROM ratings_source;
+
+-- Introduce diffs:
+-- 5 deleted rows (IDs 10-14 missing from target)
+DELETE FROM ratings_target WHERE id BETWEEN 10 AND 14;
+
+-- 5 extra rows in target only (IDs 1001-1005)
+INSERT INTO ratings_target (id, user_id, movie_id, rating, created_at) VALUES
+    (1001, 201, 51, 4.0, '2025-06-01 00:00:00'),
+    (1002, 202, 52, 3.0, '2025-06-02 00:00:00'),
+    (1003, 203, 53, 5.0, '2025-06-03 00:00:00'),
+    (1004, 204, 54, 2.0, '2025-06-04 00:00:00'),
+    (1005, 205, 55, 1.0, '2025-06-05 00:00:00');
+
+-- 10 updated ratings (IDs 100-109 have different ratings in target)
+UPDATE ratings_target SET rating = rating + 0.5 WHERE id BETWEEN 100 AND 109 AND rating < 5.0;
+UPDATE ratings_target SET rating = 1.0             WHERE id BETWEEN 100 AND 109 AND rating >= 5.0;

docker-compose.yml

@@ -12,6 +12,7 @@ services:
       restart: always
       volumes:
         - postgresql-data:/var/lib/postgresql/data:delegated
+        - ./dev/seed/postgres:/docker-entrypoint-initdb.d:ro
       ports:
         - '5432:5432'
       expose:
@@ -42,6 +43,7 @@ services:
       restart: always
       volumes:
         - mysql-data:/var/lib/mysql:delegated
+        - ./dev/seed/mysql:/docker-entrypoint-initdb.d:ro
       user: mysql
       ports:
         - '3306:3306'
@@ -61,6 +63,7 @@ services:
     clickhouse:
       container_name: dd-clickhouse
       image: clickhouse/clickhouse-server:24.3
+      profiles: [full]
       restart: always
       volumes:
           - clickhouse-data:/var/lib/clickhouse:delegated
@@ -88,6 +91,7 @@ services:
 
     # prestodb.dbapi.connect(host="127.0.0.1", user="presto").cursor().execute('SELECT * FROM system.runtime.nodes')
     presto:
+        profiles: [full]
         container_name: dd-presto
         build:
             context: ./dev
@@ -101,6 +105,7 @@ services:
             - local
 
     trino:
+        profiles: [full]
         container_name: dd-trino
         image: 'trinodb/trino:439'
         hostname: trino
@@ -118,6 +123,7 @@ services:
 
     vertica:
       container_name: dd-vertica
+      profiles: [full]
       image: vertica/vertica-ce:24.1.0-0
       restart: always
       volumes:

tests/common.py

@@ -27,14 +27,12 @@
 TEST_BIGQUERY_CONN_STRING: str = os.environ.get("DATADIFF_BIGQUERY_URI") or None
 TEST_REDSHIFT_CONN_STRING: str = os.environ.get("DATADIFF_REDSHIFT_URI") or None
 TEST_ORACLE_CONN_STRING: str = None
-TEST_DATABRICKS_CONN_STRING: str = os.environ.get("DATADIFF_DATABRICKS_URI")
+TEST_DATABRICKS_CONN_STRING: str = os.environ.get("DATADIFF_DATABRICKS_URI") or None
 TEST_TRINO_CONN_STRING: str = os.environ.get("DATADIFF_TRINO_URI") or None
-# clickhouse uri for provided docker - "clickhouse://clickhouse:Password1@localhost:9000/clickhouse"
-TEST_CLICKHOUSE_CONN_STRING: str = os.environ.get("DATADIFF_CLICKHOUSE_URI")
-# vertica uri provided for docker - "vertica://vertica:Password1@localhost:5433/vertica"
-TEST_VERTICA_CONN_STRING: str = os.environ.get("DATADIFF_VERTICA_URI")
+TEST_CLICKHOUSE_CONN_STRING: str = os.environ.get("DATADIFF_CLICKHOUSE_URI") or None
+TEST_VERTICA_CONN_STRING: str = os.environ.get("DATADIFF_VERTICA_URI") or None
 TEST_DUCKDB_CONN_STRING: str = "duckdb://main:@:memory:"
-TEST_MSSQL_CONN_STRING: str = os.environ.get("DATADIFF_MSSQL_URI")
+TEST_MSSQL_CONN_STRING: str = os.environ.get("DATADIFF_MSSQL_URI") or None
 
 
 DEFAULT_N_SAMPLES = 50