[CALCITE-5685] Support MySQL CONVERT function that works on data types

• Type: Improvement
• Status: In Progress
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 1.34.0
• Component/s: core
• Labels: pull-request-available
• Assignee: ZheHu
• Reporter: ZheHu
• Created: 04/May/23 09:34
• Updated: 23/May/23 03:41

Description

CONVERT function in MySQL has two usage：

1. convert(s USING transcodingName): as described in CALCITE-5664
2. convert(value, type): equivalent to CAST function that converts value to specific type.

Here are some examples:

• convert(150, CHAR)
• convert(now(), DATE)
• convert('9.5', DECIMAL(10, 2))
• convert(15, SIGNED)
• convert(-2, UNSIGNED)

Noted: for CONVERT or CAST function in MySQL, they only support converting to some specific data types(binary、char、date、time、datetime、decimal、signed、unsigned. Moreover, the last two aren't JDBC sql Types).

 

Issue Links

• is related to: CALCITE-5346 Support for type aliases
• is related to: CALCITE-5548 Add support for MSSQL CONVERT function
• is related to: CALCITE-5664 Support CONVERT function with "USING" keyword
• links to: GitHub Pull Request #3220