expression, cmd: fix ColumnSubstitute and allow some cases to substitute (#38826) #40914
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This is an automated cherry-pick of #38826
Signed-off-by: wjhuang2016 [email protected]
What problem does this PR solve?
Issue Number: close #38736 and close #40536
Problem Summary:
Take the case from #38736,
the first argument's collation in the like function is utf8mb4_bin, and the second is binary.
So we can't substitute the first argument(utf8mb4_bin to utf8mb4_bin) since it is weakened than binary.
If the collation and coercibility don't change, it's safe to substitute.
What is changed and how it works?
If the collation and coercibility don't change, it's safe to substitute.
Check List
Tests
Side effects
Documentation
Release note
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