[CT-2373][Bug] `dbt show` doesn't work for seeds

[aranke]

dbt show --select +orders 
19:52:09  Running with dbt=1.5.0-b5
19:52:10  Found 5 models, 20 tests, 0 snapshots, 0 analyses, 309 macros, 0 operations, 3 seed files, 0 sources, 0 exposures, 0 metrics, 0 groups
19:52:10  
19:52:10  Concurrency: 3 threads (target='dev')
19:52:10  
Error: Traceback (most recent call last):
  File "/Users/chenyuli/git/dbt-core/core/dbt/cli/requires.py", line 100, in wrapper
    result, success = func(*args, **kwargs)
  File "/Users/chenyuli/git/dbt-core/core/dbt/cli/main.py", line 345, in show
    results = task.run()
  File "/Users/chenyuli/git/dbt-core/core/dbt/task/runnable.py", line 438, in run
    result = self.execute_with_hooks(selected_uids)
  File "/Users/chenyuli/git/dbt-core/core/dbt/task/runnable.py", line 401, in execute_with_hooks
    res = self.execute_nodes()
  File "/Users/chenyuli/git/dbt-core/core/dbt/task/runnable.py", line 350, in execute_nodes
    self.run_queue(pool)
  File "/Users/chenyuli/git/dbt-core/core/dbt/task/runnable.py", line 259, in run_queue
    self._raise_set_error()
  File "/Users/chenyuli/git/dbt-core/core/dbt/task/runnable.py", line 240, in _raise_set_error
    raise self._raise_next_tick
dbt.exceptions.DbtRuntimeError: Runtime Error
  Database Error in seed raw_payments (seeds/raw_payments.csv)
    can't execute an empty query

Originally posted by @ChenyuLInx in #7208 (review)

[dbeatty10]

I was about to open a bug report for this, but then I found this one.

[dbeatty10]

To be clear, the gnarly stack trace is already addressed and it displays much more nicely now (albeit still confusing if the error is intended or not):

$ dbt show -s my_seed

19:13:33  Running with dbt=1.5.0-rc1
19:13:33  Found 4 models, 0 tests, 1 snapshot, 1 analysis, 307 macros, 0 operations, 4 seed files, 3 sources, 0 exposures, 0 metrics, 0 groups
19:13:33  
19:13:33  Concurrency: 5 threads (target='postgres')
19:13:33  
19:13:33  Encountered an error:
Runtime Error
  Database Error in seed my_seed (seeds/my_seed.csv)
    can't execute an empty query

Possible improvements

For a better user experience, we could do one of two things:

1. Display a message indicating that showing seeds is not supported
2. Support showing seeds

[dbeatty10]

Workarounds in the meantime

Option 1: dbt seed --show

$ dbt seed --show -s my_seed

19:21:37  Running with dbt=1.5.0-rc1
19:21:38  Found 4 models, 0 tests, 1 snapshot, 1 analysis, 307 macros, 0 operations, 4 seed files, 3 sources, 0 exposures, 0 metrics, 0 groups
19:21:38  
19:21:38  Concurrency: 5 threads (target='postgres')
19:21:38  
19:21:38  1 of 1 START seed file dbt_dbeatty.my_seed ..................................... [RUN]
19:21:38  1 of 1 OK loaded seed file dbt_dbeatty.my_seed ................................. [INSERT 4 in 0.10s]
19:21:38  
19:21:38  Finished running 1 seed in 0 hours 0 minutes and 0.33 seconds (0.33s).
19:21:38  
19:21:38  Random sample of table: dbt_dbeatty.my_seed
19:21:38  -------------------------------------------
| id | fruit  |
| -- | ------ |
|  1 | apple  |
|  2 | orange |
19:21:38  
19:21:38  
19:21:38  Completed successfully
19:21:38  
19:21:38  Done. PASS=1 WARN=0 ERROR=0 SKIP=0 TOTAL=1

Option 2: dbt show --inline

Assuming that dbt seed has already been run, then we can use the --inline option to ref the seed:

$ dbt show --inline 'select * from {{ ref("my_seed") }}'

19:17:49  Running with dbt=1.5.0-rc1
19:17:49  Found 4 models, 0 tests, 1 snapshot, 1 analysis, 307 macros, 0 operations, 4 seed files, 3 sources, 0 exposures, 0 metrics, 0 groups
19:17:49  
19:17:50  Concurrency: 5 threads (target='postgres')
19:17:50  
19:17:50  Previewing inline node:
| id | fruit  |
| -- | ------ |
|  1 | apple  |
|  2 | orange |

If dbt seed hasn't already been run, then you'll get an error like this:

Runtime Error
  Database Error in sql operation inline_query (from remote system.sql)
    relation "dbt_dbeatty.my_seed" does not exist
    LINE 2: select * from "postgres"."dbt_dbeatty"."my_seed"

[jtcohen6]

The question is: Do we think there's actual merit in showing a Markdown table preview of a CSV file that's also available locally? (i.e. the little-known, little-used behavior of dbt seed --show)

If we were to support another command or configuration for this (#7391), that would also accomplish what Doug outlined as the second option (= preview the table already built from this seed).

[dbeatty10]

The merit comes in me being able to use my dbt show hammer 🔨 without giving any thought to the resource type(s) I am selecting.

Example use-cases:

• I want to take a peek at the datasets in a data flow through a series of steps.
• I'm collaborating with someone in GitHub, and I want to describe a series of transformations.