How do I create alias in SQL Developer?
If the alias_name contains spaces, you must enclose the alias_name in quotes. It is acceptable to use spaces when you are aliasing a column name. However, it is not generally good practice to use spaces when you are aliasing a table name. The alias_name is only valid within the scope of the SQL statement.
What is the purpose of table alias in SQL?
In SQL, you can alias tables and columns. A table alias is also called a correlation name. A programmer can use an alias to temporarily assign another name to a table or column for the duration of a SELECT query. Assigning an alias does not actually rename the column or table.
How alias is used in SQL?
An SQL alias is a reference name for a table or a column. They are used to shorten your queries if you have long table names. Both table and column aliases are defined using the AS keyword. An alias lasts until a query has executed.
What is table alias in SQL Server?
SQL aliases are used to give a table, or a column in a table, a temporary name. Aliases are often used to make column names more readable. An alias only exists for the duration of that query. An alias is created with the AS keyword.
What is alias used for?
Definition of alias : otherwise called : otherwise known as —used to indicate an additional name that a person (such as a criminal) sometimes uses John Smith alias Richard Jones was identified as the suspect.
WHERE are aliases not allowed in SQL?
You can use the alias in GROUP BY, ORDER BY, or HAVING clauses to refer to the column. 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.
Can you GROUP BY an alias in SQL?
Aliases can be used only if they were introduced in the preceding step. So aliases in the SELECT clause can be used in the ORDER BY but not the GROUP BY clause. Reference: Microsoft T-SQL Documentation for further reading.