Using Nested Case Expression

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I am stuck in properly using Nested Case Expression.

The requirement is to create the calculated column that will be either 0 or 1. If the name is 'abc' and ind = 1, then the value of calc column will be 1 . But if the name is 'abc' and salary is > 2000 . then the value will be 1 again irrespective the value of ind.

I have written the below query using OR condition in CASE Expression but want to use the Nested CASE.

select t.*,  case when (name = 'abc' and ind = 1 ) or (name = 'abc' and sal > 2000) 
                  then 1 
                  else 0 
                  end 
from test t

Below is the result:

You don't need nested CASE:

-- multiple conditions
select t.*, case when name = 'abc' and ind = 1 then 1
                 when name = 'abc' and sal > 2000 then 1 
                 else 0 end 
from test t

Nested CASE Statement With ELSe (SQL Server), First, you don't need to nest case statements. Just use one case: select (CASE WHEN A IS NULL AND B IN ('C', 'D') THEN NULL WHEN A IS  A popular use for the IF function is creating nested formulas that can check for various criteria. However, nested IF statements can get pretty complicated and cumbersome when dealing with several conditions. Excel has introduced the SWITCH function which can essentially do what nested IF functions can, using only one function.

I don't know why you need nested case expression, i would do instead of nested case expression that would be more efficient :

select t.*, (case when name = 'abc' and (ind = 1 or sal > 2000) 
                  then 1 
                  else 0 
             end) 
from test t;

Nested case statements vs multiple criteria case statements [closed], Had an interesting discussion with a colleague today over optimizing case statements and whether it's better to leave a case statement which  Nested Case Statement in SQL Server. This article is a continuation of SQL Server CASE Statement and CASE WHEN Examples . Today we will learn about Nested Case Statement in SQL Server. We can nest CASE statements similar to nested ifs that we find in most programming languages. Let us see an example. select ename, job, sal, case -- Outer Case when ename like 'A%' then case when sal >= 1500 then 'A' -- Nested Case end when ename like 'J%' then case when sal >= 2900 then 'J' -- Nested Case

If you HAVE to have nested case expression then this is how you would write it:

SELECT t.*, 
    CASE 
        WHEN name = 'abc' THEN
            CASE 
                WHEN ind = 1 THEN 1 
                WHEN sal > 2000 THEN 1 
                ELSE 0
            END 
        ELSE 0
    END
FROM test t;

Best way to do nested case statement logic in SQL Server, Try using COALESCE trick, like this: SELECT COALESCE(. CASE WHEN condition1 THEN calculation1 ELSE NULL END,. CASE WHEN  Using Nested CASE Expressions in SQL Server Note: This article is intended for developers who have a working knowledge of SQL Server’s CASE expression. If you do not, I reading this article from Microsoft; it gives a pretty good overview of the basics.

If you are on SQL Server 2012 and above, you can also use an IIF statement like below:

select iif(name = 'abc' AND (salary > 2000 OR ind = 1), 1,0)

Dirty Secrets of the CASE Expression, Case expressions may only be nested to level 10. In some cases, you can rewrite it as Paul suggested, with an expression like this (assuming  You can use nested CASE statements so that the return value is a CASE expression. However, if you’re reaching the limit of 255 expressions, I would be looking at the efficiency of the query itself, as most queries should not need 255 expressions.

CASE statement in SQL Server: T-SQL Example, Nested CASE: CASE inside CASE; CASE with UPDATE; CASE with Order by. What is CASE? CASE is the extension of IFELSE statement. Answer: Yes, you can embed CASE statements within CASE statements, nested them. Here is an example: CASE WHEN certv.id IS NOT NULL THEN NULL WHEN cert.id IS NOT NULL THEN CASE WHEN gr.gt_id = 0 THEN = 3 WHEN gr.gt_id = 1 THEN = 4 END WHEN not.id IS NOT NULL THEN NULL END as type_pre, As we see, Oracle allows nested CASE operators.

Nested Case Statement in SQL Server, SQL Server Nested Case Statement with Examples. We will learn about a CASE inside CASE. In SQL, you can use a CASE expression to change the contents of a table field from a definite value to a null value. The null value indicates that you no longer know the field’s value. Consider the following example. Imagine that you own a small airline that offers flights between Southern California and Washington state.

Nested Case Statement possible? – SQLServerCentral, You can also rewrite this using a single CASE statement, which is usually more succinct and therefore easier to follow. Select. case when  The CASE expression evaluates a list of conditions and returns one of the multiple possible results. You can use a CASE expression in any statement or clause that accepts a valid expression. For example, you can use the CASE expression in statements such as SELECT, UPDATE, or DELETE, and in clauses like SELECT, WHERE, HAVING, and ORDDER BY.