cherry-pick from v8.5.4: MySQL compatibility about decimal insert through jdbc (#22007)

[ti-chi-bot]

This is an automated cherry-pick of #22007

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[gemini-code-assist]

Summary of Changes

Hello @ti-chi-bot, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request enhances the developer guide by adding a new section on MySQL compatibility, specifically addressing how TiDB handles DECIMAL data insertions when the number of decimal places exceeds the defined scale. It clarifies the behavioral shift in TiDB v8.5.4 to match MySQL's consistent truncation logic, ensuring better compatibility for users.

Highlights

• Documentation Update: Added a new section to the developer guide detailing MySQL compatibility for DECIMAL data insertion.
• Behavioral Alignment: Documented the change in TiDB's DECIMAL truncation behavior from v8.5.4, which now aligns with MySQL's approach of automatically truncating extra decimal places regardless of their count.

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Changelog

• develop/dev-guide-sample-application-java-jdbc.md
  • Added a new section titled "MySQL compatibility" to explain TiDB's behavior when inserting DECIMAL values with excessive decimal places, comparing it to MySQL's behavior and detailing changes in TiDB v8.5.4.

Activity

• This pull request is an automated cherry-pick of Do not merge until v8.5.4: MySQL compatibility about decimal insert through jdbc #22007.
• The Contributor License Agreement has been signed.
• The changes are marked to apply to TiDB v8.5 versions.

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[gemini-code-assist]

Code Review

This pull request adds a section on MySQL compatibility regarding DECIMAL column insertions. The new content is clear and accurate, but it can be improved for conciseness and readability by reducing repetition, as per the repository's documentation style guide. I've provided a suggestion to make the text more direct and easier to understand.

[qiancai]

/approve

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: qiancai

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