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⚈ You are trying to wrap your head around how My SQL handles CHARSET / COLLATION. And it even can involve deciding whether two different bit strings compare 'equal'. 1970's -- 7-bit ASCII becomes common -- that limits you to English.

1950's -- A character was (sometimes) represented in only 5 bits, on "paper tape"; no lowercase; had to "shift" to switch between letters and digits. And the 8-bit "byte" was invented and was coming into common usage (re: IBM 360). Especially since 7-bit ASCII was wasting a bit of the omni-present "byte". 1990's -- The computer world realizes that there are other people in the world and embarks on Unicode and UTF8.

⚈ The client receives the two bytes C389, thinking it is é (because of SET NAMES).

If you are running My SQL before 5.5.3, you have only 'utf8'.

Thus, xxx_unicode_520_ci collations are based on UCA 5.2.0 weight keys: https://

Collations without the "520", are based on the older UCA 4.0.0.

There are 3 dimensions to character set problems: ⚈ How the client's bytes are encoded when INSERTing, and what encoding you want when SELECTing; ⚈ What SET NAMES you use (or what the default is); ⚈ The CHARACTER SET on the column definition.

All is well if the SET NAMES agrees with the encoding of the bytes in the Client.

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