mysql varius sentences

1. I see all foreign keys to a table or column: SELECT TABLE_NAME,COLUMN_NAME,CONSTRAINT_NAME, REFERENCED_TABLE_NAME,REFERENCED_COLUMN_NAME FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE WHERE REFERENCED_TABLE_NAME = '<table>'
2. Distinc values in 2 columns from 2 tables:SELECT
    SELECT DISTINCT t1.`ID_POSTULANTE` AS T1_ID_POSTULANTE FROM
     `tb_postulante` t1 INNER JOIN `aulaasignada` as t2
      ON t1.`ID_POSTULANTE` != t2.`ID_POSTULANTE`
      GROUP BY T1_ID_POSTULANTE
3. values duplicate for one column: SELECT certificado_id_correlativo FROM t_certificado_digital group by certificado_id_correlativo having count(*) >= 2
4. update from select: update tabla1 inner join tabla2 on tabla1.id_tabla2 = tabla2.id set tabla1.campo=tabla2.language
   
5. update year sales: update sales set created_at=DATE_FORMAT(created_at, '2020-%m-%d') where YEAR(created_at) < 2020 ;
6. update month sales: update sales set created_at=DATE_FORMAT(created_at, '%y-10-%d') where MONTH(created_at) < 10 ;
7. update day sales: update sales set created_at=DATE_FORMAT(created_at, '%y-%m-25') where DAY(created_at) < 10 and MONTH(created_at) = 10 ;
8. update month invertval sales: update sales set created_at=date_add(created_at, interval 1 month);
9. insert select:
   
1. INSERT INTO generic_stage.entity_items (
       client_id,
       item_type_id,
       item_id,
       action_type,
       action_result,
       marketing_flag,
       creation_timestamp
   )
   SELECT
       '300001' AS client_id,
       8 AS item_type_id,
       cg.id AS item_id,
       1 AS action_type,
       1 AS action_result,
       0 AS marketing_flag,
       NOW() AS creation_timestamp -- use NOW() for current timestamp
   FROM generic_source.item_source cg
   WHERE source_provider_id = 7;
10. 
    

•  https://stackoverflow.com/questions/201621/how-do-i-see-all-foreign-keys-to-a-table-or-column
• http://www.dataprix.com/blog-it/dml/como-hacer-update-select-mysql