It seems to SLiMS 9 Bulian are using both PDO and MySQLi? Or an abstraction DB like ADOdb?

Sometimes, I custom some codes for my library and I feel "something wrong", and I had to edit code lines , some cases it looked like PDO, and some case, it looks like  MySQLi.

So, I have a question: Should I use PDO or MySQLi? (for compatble in the future when I want to upgrade current SLiMS to a newer version?). SLiMS's developers will support which?
SLiMS uses PDO or MySQLi for future?
This is a GitHub Issue
repo:slims9_bulian
owner:slims
Title : SLiMS uses PDO or MySQLi for future?
Issue date:

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It seems to SLiMS 9 Bulian are using both PDO and MySQLi? Or an abstraction DB like ADOdb?

Sometimes, I custom some codes for my library and I feel "something wrong", and I had to edit code lines , some cases it looked like PDO, and some case, it looks like  MySQLi.

So, I have a question: Should I use PDO or MySQLi? (for compatble in the future when I want to upgrade current SLiMS to a newer version?). SLiMS's developers will support which?
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