pt/pipekit
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Wizard: don't clobber pre-existing dest tables.

Browse Source 
If the dest table already exists, introspect its columns and verify the
wizard's picks line up. Missing columns surface a specific error message
naming what's missing instead of the opaque "column X does not exist"
from a failed COMMENT. On match, skip CREATE + COMMENT so existing
schema and comments aren't touched; staging still gets provisioned.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
This commit is contained in:
Paul Trowbridge 2026-04-23 00:41:00 -04:00
parent 4650a3cbc5
commit fde4fa99b6
1 changed files with 40 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

45
pipekit/web/app.py
View File

@ -436,16 +436,36 @@ async def wizard_create(request: Request):
effective_staging = staging_table or f"pipekit_staging.{module_name}"
staging_schema, _, _ = effective_staging.partition(".")
# If the dest table already exists, don't clobber it. Verify the picks
# match its shape and skip CREATE/COMMENT.
try:
existing_cols = _existing_dest_columns(
dest_conn, dest_schema, dest_table_bare)
except jrunner.JrunnerError as e:
raise HTTPException(500, f"could not introspect dest: {e}")
dest_exists = existing_cols is not None
if dest_exists:
missing = [c["dest_name"] for c in chosen
if c["dest_name"].lower() not in existing_cols]
if missing:
raise HTTPException(
400,
f"dest table {qualified_dest} already exists but is missing "
f"columns: {', '.join(missing)}. Drop the table, choose a "
f"different dest_table, or align your column picks to match "
f"the existing schema.")
try:
jrunner.run_dest_sql(
dest_conn,
f"CREATE SCHEMA IF NOT EXISTS {dest_drv.quote_identifier(dest_schema)};",
)
jrunner.run_dest_sql(dest_conn, create_table_sql)
comment_sql = _build_comment_sql(dest_drv, qualified_dest,
dest_description, chosen)
if comment_sql:
jrunner.run_dest_sql(dest_conn, comment_sql)
if not dest_exists:
jrunner.run_dest_sql(dest_conn, create_table_sql)
comment_sql = _build_comment_sql(dest_drv, qualified_dest,
dest_description, chosen)
if comment_sql:
jrunner.run_dest_sql(dest_conn, comment_sql)
# Pre-align staging to dest so first run doesn't surprise us.
if staging_schema and staging_schema != effective_staging:
jrunner.run_dest_sql(
@ -482,6 +502,21 @@ def _sql_str(v: str) -> str:
return "'" + v.replace("'", "''") + "'"
def _existing_dest_columns(dest_conn: dict, schema: str,
table: str) -> set[str] | None:
"""Return lowercase column names of an existing PG dest table, or
None if it doesn't exist. PG-only; fine while pg is the sole dest."""
r = jrunner.run_dest_sql(
dest_conn,
f"SELECT column_name FROM information_schema.columns "
f"WHERE table_schema={_sql_str(schema)} "
f"AND table_name={_sql_str(table)}",
)
if not r.rows:
return None
return {row[0].strip().lower() for row in r.rows if row and row[0]}
def _build_comment_sql(dest_drv, qualified_dest: str,
table_description: str | None,
columns: list[dict]) -> str: