fix: EXPOSED-340 Syntax error using upsert with MySQL8 below 8.0.19 (#…

…2049)

* fix: EXPOSED-340 Syntax error using upsert with MySQL8 below 8.0.19

MySQL `upsert()` uses an alias for the insert row values when the database
version is 8+.
Technically this is only possible starting with version 8.0.19.

Existing function `MysqlDialect.isMysql8` calls `isVersionCovers()`, which only
fetches the database's major and minor version, so it is not sufficient for
this comparison.
To get the patch version as well requires fetching metadata using the full
`databaseProductVersion` property.

exposed-core/src/main/kotlin/org/jetbrains/exposed/sql/vendors/MysqlDialect.kt

@@ -243,7 +243,7 @@ internal open class MysqlFunctionProvider : FunctionProvider() {
         }
 
         val isAliasSupported = when (val dialect = transaction.db.dialect) {
-            is MysqlDialect -> dialect !is MariaDBDialect && dialect.isMysql8
+            is MysqlDialect -> dialect !is MariaDBDialect && dialect.fullVersion >= "8.0.19"
             else -> false // H2_MySQL mode also uses this function provider & requires older version
         }
 
@@ -281,6 +281,10 @@ open class MysqlDialect : VendorDialect(dialectName, MysqlDataTypeProvider, Mysq
         TransactionManager.current().db.isVersionCovers(BigDecimal("8.0"))
     }
 
+    internal val fullVersion: String by lazy {
+        TransactionManager.current().db.metadata { databaseProductVersion }
+    }
+
     override val supportsCreateSequence: Boolean = false
 
     override val supportsTernaryAffectedRowValues: Boolean = true