JdbcDatabaseDialect exposes deprecated dialiect for MySQL

[snicoll]

See 04e58c9#diff-7ea1fe46e523c52f235c422412290a54e9c0577f65661e2d94f7da68259d5bd7R54

There is no alternative to create the dialect without passing extra settings so we'll have to figure out if we want to deprecate them as well or offer an alternative solution

cc @mp911de

[schauder]

Thought I add some background to why those default instances got deprecated.

MySql and MariaDb don't have a fixed behavior regarding things that are defined in the Dialect.
The character for quoting may vary depending on the database configuration.
If names are case sensitive depends on the underlying OS.

You can always construct a replacement for the deprecated instances, that behaves the same. See
https://github.com/spring-projects/spring-data-relational/blob/d8e47686728a87655d9cf6cdc9f0c965271a8ed6/spring-data-relational/src/main/java/org/springframework/data/relational/core/dialect/MySqlDialect.java#L50

The preferred way is to actually consult the database connection which should provide the necessary information in its meta data. https://github.com/spring-projects/spring-data-relational/blob/94958f5eb66cbe2e8e025155cd99abf36f6f91f4/spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/dialect/DialectResolver.java#L120

With the obvious drawback that it requires an actual database connection.

HTH a little.