COPY statements incorrectly classified as "Unknown" instead of "Copy"

[fspoljar]

Summary

Snowflake COPY statements are misclassified as "Unknown" statement type, causing them to be rejected when sql_statement_permissions is configured with Copy: true and Unknown: false.

Expected Behavior

When executing a Snowflake COPY statement with Copy: true in permissions, the statement should be recognized as type "Copy" and allowed to execute.

Actual Behavior

The statement is classified as "Unknown" and rejected. Setting Unknown: true is required as a workaround.

Steps to Reproduce

1. Configure tools_config.yaml with:

   sql_statement_permissions:
     - Copy: true
     - Unknown: false

2. Execute a Snowflake COPY statement:

   COPY INTO @MY_STAGE.EXPORTS/sales_export.csv.gz
   FROM (
       SELECT * FROM MY_DATABASE.PUBLIC.ORDERS LIMIT 10
   )
   FILE_FORMAT = (TYPE = CSV COMPRESSION = GZIP)
   HEADER = TRUE
   OVERWRITE = TRUE
   MAX_FILE_SIZE = 52428800
   SINGLE = TRUE;

3. Observe that the query is rejected

4. Change config to Unknown: true — the query now executes (confirming misclassification)

Additional Context

The issue appears to be in mcp_server_snowflake/query_manager/tools.py where sqlglot.parse_one() is called without specifying dialect="snowflake". This causes the parser to fail on Snowflake-specific syntax.

Verification script:

import sqlglot

COPY_QUERY = """COPY INTO @MY_STAGE.EXPORTS/sales_export.csv.gz
FROM (SELECT * FROM MY_DATABASE.PUBLIC.ORDERS LIMIT 10)
FILE_FORMAT = (TYPE = CSV COMPRESSION = GZIP) HEADER = TRUE OVERWRITE = TRUE
MAX_FILE_SIZE = 52428800 SINGLE = TRUE;"""

# Without dialect - raises ParseError
try:
    result = sqlglot.parse_one(COPY_QUERY)
except sqlglot.errors.ParseError:
    print("Classified as: Unknown")

# With Snowflake dialect - parses correctly
result = sqlglot.parse_one(COPY_QUERY, dialect="snowflake")
print(f"Classified as: {type(result).__name__}")  # Prints "Copy"

[atvaccaro]

This also occurs in other situations, such as parsing JSON with Snowflake-specific syntax.