SNOW-2187773 Add basic support for DECFLOAT (#2599)

* SNOW-2187773 Set Decimal precision to 38

* bring empty line back

* add test for DECFLOAT; improved setting precision so it works in the real snow execution and in tests

Author: sfc-gh-daniszewski

RELEASE-NOTES.md

@@ -40,6 +40,7 @@
 * Fixed issues when pasting content with trailing new lines.
 * Improved output handling  with streaming
 * Bumped `snowflake-connector-python` to 3.17.3
+* Extend `Decimal` precision to 38
 
 
 # v3.11.0

src/snowflake/cli/_app/__init__.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import decimal
 import logging
 import os
 
@@ -20,3 +21,6 @@
 
 # Restrict permissions of all created files
 os.umask(0o077)
+
+# Set Decimal precision to reflect precision on Snowflake
+decimal.getcontext().prec = 38

src/snowflake/cli/_plugins/snowpark/common.py

@@ -349,6 +349,7 @@ def user_to_sql_type_mapper(user_provided_type: str) -> str:
             "FLOAT4",
             "FLOAT8",
         ),
+        ("DECFLOAT", ""): ("DECFLOAT",),
         ("TIMESTAMP_NTZ", ""): ("TIMESTAMP_NTZ", "TIMESTAMPNTZ", "DATETIME"),
         ("TIMESTAMP_LTZ", ""): ("TIMESTAMP_LTZ", "TIMESTAMPLTZ"),
         ("TIMESTAMP_TZ", ""): ("TIMESTAMP_TZ", "TIMESTAMPTZ"),

src/snowflake/cli/_plugins/sql/lexer/types.py

@@ -11,6 +11,7 @@
     "DATETIME",
     "DEC",
     "DECIMAL",
+    "DECFLOAT",
     "DOUBLE",
     "FLOAT",
     "INT",

tests_integration/sql/test_sql.py

@@ -347,3 +347,34 @@ def test_nested_json_backward_compatibility(runner):
     assert "profile" in user_obj
     assert "Alice" in user_obj
     assert "dark" in user_obj
+
+
+@pytest.mark.integration
+@pytest.mark.qa_only
+def test_decfloat_values(runner):
+    """Test DECFLOAT type with various value types: positive/negative, maximum/minimum, floating point."""
+
+    sql = """
+        SELECT 
+            CAST('123456789012345678901234567890.123456789' AS DECFLOAT) AS positive_value,
+            CAST('-123456789012345678901234567890.123456789' AS DECFLOAT) AS negative_value,
+            CAST('3.14159265358979323846264338327950288419' AS DECFLOAT) AS floating_point,
+            CAST('99999999999999999999999999999999999999e16384' AS DECFLOAT) AS maximum_value,
+            CAST('-99999999999999999999999999999999999999e16384' AS DECFLOAT) AS minimum_value,
+    """
+
+    result = runner.invoke_with_connection_json(["sql", "-q", sql])
+    assert result.exit_code == 0, f"Failed to select DECFLOAT values: {result.output}"
+
+    # Verify JSON response contains expected values
+    assert len(result.json) == 1
+    row = result.json[0]
+
+    # Assert exact values that Snowflake returns for DECFLOAT
+    assert row["POSITIVE_VALUE"] == "123456789012345678901234567890.12345679"
+    assert row["NEGATIVE_VALUE"] == "-123456789012345678901234567890.12345679"
+    assert (
+        row["FLOATING_POINT"] == "3.1415926535897932384626433832795028842"
+    )  # value is rounded up to 38 numbers
+    assert row["MAXIMUM_VALUE"] == "9.9999999999999999999999999999999999999E+16421"
+    assert row["MINIMUM_VALUE"] == "-9.9999999999999999999999999999999999999E+16421"