Pinot bug fix

[ege-st]

SUMMARY

This fixes two bugs in the Apache Pinot DB Engine spec:

1. If a column was marked as temporal and no time grain was provided then the query would be constructed with illegal {} around the column name causing Pinot to reject the query as syntactically invalid. The code has been updated to remove the incorrect {}
2. In some cases, get_timestamp_expr will be called by models.adhoc_column_to_sqla and None is explicitly passed for the pdf parameter. This would cause the Pinot get_timestamp_expr to fault. To fix this, the models.adhoc_column_to_sqla method is updated to get the python_date_format for a column (if that data is available). (Without this fix, queries created for charts simply do not use the date format a user sets for a temporal column).

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

TESTING INSTRUCTIONS

1. Connected to a Pinot data set and marked a long column as epoch_ms and tested creating a Bar Chart V2 to confirm that the query would be correctly constructed (this tested the issue where None is passed for the pdf parameter.
2. Setting a String column as temporal and using %Y-%m-%d as the PDF value and confirming that when a chart is created the correct Date Time conversion function is used to parse the text date time.

ADDITIONAL INFORMATION

• Has associated issue:
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API