[FLINK-19119] Update the documentation to use Expression instead of strings in the Python Table API

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.12.0
• Component/s: API / Python, Documentation
• Labels: pull-request-available
• Assignee: Dian Fu
• Reporter: Dian Fu
• Created: 02/Sep/20 02:10
• Updated: 09/Sep/20 12:03
• Resolved: 09/Sep/20 12:03

Issue Links

• links to: GitHub Pull Request #13348