Contents
Can we use column alias name in WHERE clause?
Column aliases can be used for derived columns. Column aliases can be used with GROUP BY and ORDER BY clauses. We cannot use a column alias with WHERE and HAVING clauses.
Can you ORDER BY column alias?
You can specify in an ORDER BY clause any select-item by column alias or column number, including an aggregate function, window function, or expression. Otherwise a column name or column alias is assumed. Note that column names and column aliases are not case-sensitive.
Can we use alias in GROUP BY clause?
SQL Server doesn’t allow you to reference the alias in the GROUP BY clause because of the logical order of processing. The GROUP BY clause is processed before the SELECT clause, so the alias is not known when the GROUP BY clause is evaluated. This also explains why you can use the alias in the ORDER BY clause.
Can we use alias in WHERE clause SQL?
An alias can be used in a query select list to give a column a different name. 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.
Is an alias required for a column created in the SELECT clause?
Column aliases are optional, and each column name in the SELECT clause can have an alias. After you assign an alias to a column, you can use the alias to refer to that column in other clauses.
Can we use two order by clause in query?
SQL ORDER BY Multiple Columns However we can use multiple columns in ORDER BY clause. When multiple columns are used in ORDER BY, first the rows will be sorted based on the first column and then by the second column.
How do I use column alias in GROUP BY?
A column alias may be used in the ORDER BY clause but not in the GROUP BY clause. So after the ORDER BY an expression is allowed, a position ( order by 1 ) or a c_alias which stands for “column alias”. As you can see, no c_alias option after it, so you can’t use a column alias.
How do I give an alias to multiple columns in SQL?
Yes, you can alias multiple columns at a time in the same query. It is advisable to always include quotes around the new alias. Quotes are required when the alias contains spaces, punctuation marks, special characters or reserved keywords. It is simply more convenient to always include quotes around the new alias.