Return Boolean Value on SQL Select Statement

Question

How to return a boolean value on SQL Select Statement   I tried this code   SELECT CAST 1 AS BIT  AS Expr1 FROM  User  WHERE  UserID   20070022    And it only returns TRUE if the UserID exists on the table  I want it to return FALSE if the UserID doesn t exist on the table

User · Answer

For those of you who are interested in getting the value adding a custom column name, this worked for me:

CAST(
    CASE WHEN EXISTS ( 
           SELECT * 
           FROM mytable 
           WHERE mytable.id = 1
    ) 
    THEN TRUE 
    ELSE FALSE 
    END AS bool) 
AS "nameOfMyColumn"

You can skip the double quotes from the column name in case you're not interested in keeping the case sensitivity of the name (in some clients).

I slightly tweaked @Chad's answer for this.

User · Answer

Possibly something along these lines   SELECT CAST CASE WHEN COUNT     gt  0 THEN 1 ELSE 0 END AS BIT  FROM dummy WHERE id   1    http   sqlfiddle com   3 5e555 1

User · Answer

What you have there will return no row at all if the user doesn t exist  Here s what you need   SELECT CASE WHEN EXISTS       SELECT       FROM  User      WHERE UserID   20070022   THEN CAST 1 AS BIT  ELSE CAST 0 AS BIT  END

User · Answer

Notice another equivalent problem  Creating an SQL query that returns  1  if the condition is satisfied and an empty result otherwise  Notice that a solution to this problem is more general and can easily be used with the above answers to achieve the question that you asked  Since this problem is more general  I am proving its solution in addition to the beautiful solutions presented above to your problem   SELECT DISTINCT 1 AS Expr1 FROM  User  WHERE  UserID   20070022

User · Answer

Use  Exists  which returns either 0 or 1   The query will be like   SELECT EXISTS SELECT   FROM USER WHERE UserID   20070022

User · Answer

Given that commonly 1   true and 0   false  all you need to do is count the number of rows  and cast to a boolean   Hence  your posted code only needs a COUNT   function added   SELECT CAST COUNT 1  AS BIT  AS Expr1 FROM  User  WHERE  UserID   20070022

User · Answer

I do it like this   SELECT 1 FROM  dbo   User  WHERE UserID   20070022   Seeing as a boolean can never be null  at least in  NET   it should default to false or you can set it to that yourself if it s defaulting true  However 1   true  so null   false  and no extra syntax   Note  I use Dapper as my micro orm  I d imagine ADO should work the same

User · Answer

DECLARE  isAvailable      BIT   0   IF EXISTS SELECT 1  FROM  User  WHERE  UserID   20070022   BEGIN  SET  isAvailable   1 END   initially isAvailable boolean value is set to 0

User · Answer

select CAST COUNT    AS BIT  FROM  User  WHERE  UserID   20070022    If count      0 returns false  If count      0 returns true

[sql] Return Boolean Value on SQL Select Statement

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