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Can a column alias be used in a where clause?
column_alias can be used in an ORDER BY clause, but it cannot be used in a WHERE, GROUP BY, or HAVING clause. Standard SQL disallows references to column aliases in a WHERE clause. This restriction is imposed because when the WHERE clause is evaluated, the column value may not yet have been determined. You can’t, not directly.
Can you use an alias in a select list?
You can’t use an alias ( KODE) defined in the SELECT list, in the definition of another column in that list. You have to use the full reference instead ( ANGGARAN.SIMPEG_PEGAWAI.ID_PEGAWAI ). But the solution provided, does not work I think because of the double nesting.
Can a column be referenced in an inline subquery?
You can reference a column in a inline subquery but not in a derived table inside an inline subquery. This would require either using ROW_NUMBER () and encapsulating the whole query ina derived table or turning the inline subquery into a LEFT JOIN.
How to alias lead informations in PostgreSQL stack?
SELECT jobs.*, ( CASE WHEN lead_informations.state IS NOT NULL THEN lead_informations.state ELSE ‘NEW’ END ) AS lead_state FROM jobs LEFT JOIN lead_informations ON lead_informations.job_id = jobs.id AND lead_informations.mechanic_id = 3 WHERE lead_state = ‘NEW’
How to use column name in where clause in SQL Server?
The problem is that you can only use names in the scope of the table (s) you select inside the where clause. Where is a pre filter that filter out rows before they are selected, so expressions like this in the field definition are not executed yet and the aliases are therefor not available.
Is there a common workaround for the where clause in PostgreSQL?
In MySql this is valid, but apparently not in Postgresql. From what I can gather, the reason is that the SELECT part of the query is evaluated later than the WHERE part. Is there a common workaround for this problem?