fix: drop trigger/function order

[tianzhou]

Fix #148

[Copilot]

Pull Request Overview

This PR fixes a dependency ordering issue in SQL migration generation by ensuring triggers are dropped before their associated functions when functions are being replaced or removed. This prevents PostgreSQL errors where a function cannot be dropped while triggers still reference it.

Key changes:

• Added generateDropTriggersFromModifiedTables function to collect and drop triggers from modified tables before functions are dropped
• Integrated this function into the generateDropSQL workflow to enforce proper dependency ordering
• Updated test data to reflect the corrected drop order

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
internal/diff/trigger.go	Added new function to handle dropping triggers from modified tables with proper ordering
internal/diff/diff.go	Integrated trigger drop function into the drop SQL generation workflow
testdata/diff/dependency/function_to_trigger/*.sql	Updated test data to reflect correct drop order (trigger first, then function)
testdata/diff/dependency/function_to_trigger/*.txt	Updated plan output showing correct execution order
testdata/diff/dependency/function_to_trigger/*.json	Updated JSON plan with proper step ordering

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[Copilot]

Pull Request Overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.

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[Copilot]

Pull Request Overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated no new comments.

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