Can I use alias in case?

Can I use alias in case?

The Case statement in SQL is mostly used in a case with equality expressions. The SQL Case statement is usually inside of a Select list to alter the output. Another way to do aliases is to put the name of the alias first followed by equals SQL Case on “MaritalStatus” as in the example above.

What are the valid names for a column?

Column names can contain any valid characters (for example, spaces). If column names contain any characters except letters, numbers, and underscores, the name must be delimited by enclosing it in back quotes (`).

How do you put an alias in a case statement?

1. If you write only equal condition just: Select Case columns1 When 0 then ‘Value1’ when 1 then ‘Value2’ else ‘Unknown’ End.
2. If you want to write greater , Less then or equal you must do like this: Select Case When [ColumnsName] >0 then ‘value1’ When [ColumnsName]=0 Or [ColumnsName]<0 then ‘value2’ Else ‘Unkownvalue’ End.

How do I select columns with the same name?

In a natural join, all the source table columns that have the same name are compared with each other for equality. With the column-name join, you select which same-name columns to compare. You can choose them all if you want, making the column-name join (effectively) a natural join.

Can we use in column name?

Really – just don’t do it. Think of this as a formatting thing and do any special naming of columns in your presentation layer. Honestly, anyone who ever has to use your tables in the future will curse you. We usually don’t suggest you using special characters in column name.

Why do you alias a column in SQL?

I am trying to alias the column because actually my CASE statement would be generated programmatically, and I want the column that the case statement uses to be specified in the SQL instead of having to pass another parameter to the program.

Can you reference column alias in same select list?

You cannot reference column aliases in the same SELECT list. And you can use a LATERAL join in Postgres 9.3+: How to retrieve closest value based on look-up table?

How to alias column name in MySQL case statement?

In MySql, alice name may not work, therefore put the original column name in the CASE statement Sometimes above query also may return error, I don`t know why (I faced this problem in my two different development machine). Therefore put the CASE statement into the ” (…)” as below: Not in MySQL.

How to use computed column alias in PostgreSQL?

I hit something like this migrating a 500+ line Netezza query (aka modified Postgres) to SQL Server. In Netezza the computed column alias was allowed to be used as a value in downstream references. My work around was to use CROSS APPLY with a correlated sub-query.