When do I use libmysql-6.1.dll vs libmysql.dll?

Question

I'm using HeidiSQL to edit a MYSQL database, and it's asking which library I want to use for the edits:

1. libmysql-6.1.dll
2. libmysql.dll

How do I know which one to use?

Answer 1

While the question of which library to use for MariaDB seems pretty obvious (libmariadb.dll), what to make of the other two?

As a clue, I looked a the file properties.

libmysql.dll shows ProductVersion 5.6.6.0
libmysql-6.1.dll shows ProductVersion 6.1.11.0

Given that these files are included in HeidiSql v11.3, I concluded they are NOT generated by building HeidiSql. So, where did those version numbers come from?

Poking around in C:\Program Files\MySQL\MySQL Server 8.0\lib, I see a libmysql.dll there too (ProductVersion 8.0.25).

So, my guess is that HeidiSql acquired those files from builds of MySQL. And the newer one (libmysql-6.1.dll) is probably the better bet for current releases of MySQL.

That does leave open the question of where the number "6.1" came from. It doesn't appear there was ever a 6.1 release of MySQL?

And it also doesn't address which one is best for MSSQL, PostgreSQL, etc. But that wasn't the question here.

Answer 2

These alternative libmysql*.dll and libmariadb*.dll libraries are there to solve (SSL) connectivity issues on newer MySQL and MariaDB servers. For example on MySQL 5.7, some users reported the following error with the older libmysql.dll:

ASN: bad other signature confirmation

Using libmariadb.dll may cause another error:

Unknown SSL error (0x80090308)

Especially when you provide a SSL certificate, you may run into such issues.

For this and any other connectivity issue, HeidiSQL provides alternative libraries the user can try. Apart from that, I never heard of any other advantage or disadvantage of one or another of these libraries.