Finding character set of database or table or column in MYSQL

For Schemas:

SELECT default_character_set_name FROM information_schema.SCHEMATA

WHERE schema_name = "schemaname";

For Tables:

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";

For Columns:

SELECT character_set_name FROM information_schema.`COLUMNS`  

WHERE table_schema = "schemaname" 

 AND table_name = "tablename"  

AND column_name = "columnname";

Add column with foreign key in mysql

Add only a constraint on a column

ALTER TABLE `SCHEMANAME`.`TABLE1` 
ADD CONSTRAINT `FK_TABLE2_COLUMN` FOREIGN KEY (`FK_COLUMN`)  
REFERENCES `SCHEMANAME`.`TABLE2`(`PK_COLUMN`);

Adding a column with constraint

ALTER TABLE `SCHEMANAME`.`TABLE1` 
ADD COLUMN `FK_COLUMN` BIGINT(20) NOT NULL, 
ADD CONSTRAINT `FK_TABLE2_COLUMN` FOREIGN KEY (`FK_COLUMN`) 
REFERENCES `SCHEMANAME`.`TABLE2`(`PK_COLUMN`);