{"id":1849,"date":"2019-04-06T15:29:23","date_gmt":"2019-04-06T20:29:23","guid":{"rendered":"http:\/\/creativapixel.com\/?p=1849"},"modified":"2019-04-06T15:48:22","modified_gmt":"2019-04-06T20:48:22","slug":"usar-alias-en-clausula-where-en-postgresql","status":"publish","type":"post","link":"https:\/\/creativapixel.com\/blog\/usar-alias-en-clausula-where-en-postgresql\/","title":{"rendered":"Usar Alias en clausula Where en PostgreSql"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">A veces necesitamos tomar del resultado de una query un alias como criterio para filtrar el resultado. Una forma que encontr\u00e9 fue la siguiente:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>SELECT * FROM (\n\nSELECT u.udi_id, u.udi_nombre, u.sem_codigo, m.car_id,\n\n(SELECT COUNT(mud.udi_id) FROM matricula_unidad_didactica AS mud INNER JOIN matricula AS ma ON mud.mat_id=ma.mat_id WHERE mud.udi_id=u.udi_id AND ma.sem_codigo='II' AND ma.mat_anio_academico=2015 AND mud.mud_asistencia_porcentaje>=mud.mud_asistencia_minima AND (mud.mud_nota_final >= mud.mud_nota_evaluacion_minima AND mud.mud_nota_final &lt; mud.mud_nota_minima) GROUP BY mud.udi_id) AS cantidad_evaluacion FROM unidad_didactica AS u INNER JOIN modulo AS m ON u.mod_id=m.mod_id INNER JOIN carrera AS c ON m.car_id=c.car_id WHERE u.sem_codigo = 'II' AND u.udi_eliminado = '0' ORDER BY u.udi_nombre ASC\n\n) AS tabla WHERE cantidad_evaluacion>0<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Esta query entre sus columnas devuelve una columna generada por una \nsubquery, este resultado pertenece a una query principal que usa el \nalias en el where.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Es un tip simple pero \u00fatil en algunos casos.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A veces necesitamos tomar del resultado de una query un alias como criterio para filtrar el resultado. Una forma que encontr\u00e9 fue la siguiente: Esta query entre sus columnas devuelve &#8230;<\/p>\n","protected":false},"author":1,"featured_media":1851,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[],"class_list":["post-1849","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-postgresql"],"_links":{"self":[{"href":"https:\/\/creativapixel.com\/blog\/wp-json\/wp\/v2\/posts\/1849","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/creativapixel.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/creativapixel.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/creativapixel.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/creativapixel.com\/blog\/wp-json\/wp\/v2\/comments?post=1849"}],"version-history":[{"count":1,"href":"https:\/\/creativapixel.com\/blog\/wp-json\/wp\/v2\/posts\/1849\/revisions"}],"predecessor-version":[{"id":1850,"href":"https:\/\/creativapixel.com\/blog\/wp-json\/wp\/v2\/posts\/1849\/revisions\/1850"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/creativapixel.com\/blog\/wp-json\/wp\/v2\/media\/1851"}],"wp:attachment":[{"href":"https:\/\/creativapixel.com\/blog\/wp-json\/wp\/v2\/media?parent=1849"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/creativapixel.com\/blog\/wp-json\/wp\/v2\/categories?post=1849"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/creativapixel.com\/blog\/wp-json\/wp\/v2\/tags?post=1849"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}