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Funger
Starting Member
6 Posts |
 Posted - 2005-07-11 : 15:39:05
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Hi all,I want the boolean result to be a column in a query.For example, lets say I have a [Customer] table. I want to return all of the records in the [Customer] table, and a bit value for whether the CustomerID column is 123.My first thought would be the following:SELECT (CustomerID = 123) AS MyCheck FROM Customer This, if you try it obviously doesn't work. If I try this query in EM, it changes the CustomerID = 123 into a string.I know i can use an IF, or an CASE, but I was curious if there was a way to evaluate the statement directly.Thanks for help in advance!-Funger[edit] I meant CASE not ELSE. |
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tkizer
Almighty SQL Goddess
38200 Posts |
Posted - 2005-07-11 : 15:40:53
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| You can use CASE in queries. Check SQL Server Books Online for details.SELECT CustomerID, MyCheck = CASE WHEN CustomerID = 123 THEN 1 ELSE 0 ENDFROM CustomerTara |
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Funger
Starting Member
6 Posts |
Posted - 2005-07-11 : 15:43:35
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quote:
Originally posted by tduggan
You can use CASE in queries. Check SQL Server Books Online for details.Tara
I was looking for something other then an IF or a CASE statement.I origionally came from MS Access, and was able to evaluate a boolean statement as a column rather easily, I thought there would be a SQL Server equivalent. |
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tkizer
Almighty SQL Goddess
38200 Posts |
Posted - 2005-07-11 : 15:45:27
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| I updated my post with an example. I've never used Access before so I don't know what option you are referring to.Tara |
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jsmith8858
Dr. Cross Join
7423 Posts |
Posted - 2005-07-11 : 15:51:42
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| There is no exposed boolean datatype that you can use in SQL Server; the closest is a "bit" which is either 1 or 0. SQL uses booleans internally, of course, but you cannot declare variables or table columns of that type.Expressions that return a boolean value cannot be mixed with other expression in SQL. You may notice that in Books On-Line, there are places in the syntax of variuos commands where a boolean-expression is required and others where an expression is required; there is no casting between the two types. Any expression containing any of the boolean operators (<,>,=,!=, IN, EXISTS, etc) is a boolean expression.Usually, you'd use a CASE statement to "convert" boolean expressions back and forth to non-boolean expressions in T-SQL, as Tara has demonstrated.- Jeff |
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Funger
Starting Member
6 Posts |
Posted - 2005-07-11 : 17:12:14
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| Thank you to both. :) |
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Boolean result as query column?