SELECT default_character_set_name FROM information_schema.SCHEMATA
WHERE schema_name = "schemaname";

表

SELECT CCSA.character_set_name FROM information_schema.`TABLES` T,
       information_schema.`COLLATION_CHARACTER_SET_APPLICABILITY` CCSA
WHERE CCSA.collation_name = T.table_collation
  AND T.table_schema = "schemaname"
  AND T.table_name = "tablename";

列

SELECT character_set_name FROM information_schema.`COLUMNS`
WHERE table_schema = "schemaname"
  AND table_name = "tablename"
  AND column_name = "columnname";