Comandos Mysql

mysql.md

Subconsulta update

  UPDATE dept_manager set emp_no = (select emp_no from employees limit 1) where emp_no=110039;

  UPDATE detalle_plantillas_factura dest, 
  (SELECT id_detalle_plantilla id, campo,X,Y,ancho,alto,tipo 
  FROM detalle_plantillas_factura WHERE id_plantilla_factura=102) src
  SET
    dest.campo=src.campo,
    dest.x = src.x,
    dest.y = src.y,
    dest.ancho = src.ancho,
    dest.alto = src.alto,
    dest.tipo = src.tipo
  WHERE dest.id_plantilla_factura = 458 AND dest.id_detalle_plantilla = 87258 AND src.id = 84867;

consultar del ultimo registro al primero

SELECT * FROM name_table ORDER BY id_name_table DESC;

Eliminar los datos de una tabla

DELETE FROM name_table;

Reiniciar el id de la tabla

ALTER TABLE name_table AUTO_INCREMENT = 0;

Ver que campos tiene la tabla

DESC name_table;

Maneras de hacer un backup en mysql

• To export to file (data only) mysqldump -u [user] -p[pass] --no-create-info mydb > mydb.sql

• To export to file (structure only) mysqldump -u [user] -p[pass] --no-data mydb > mydb.sql

• To import to database mysql -u [user] -p[pass] mydb < mydb.sql