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    <p><strong>EDITED AND UNDELETED</strong></p> <p>Answer to A.: Yes, or you can use ISNULL() with the same result as COALESCE() in this case.</p> <p>Answer to B.: Do not convert a varchar to a varbinary to compare them, but <strong>understand the collation sort order when using aggregates.</strong></p> <p>I think this code snippet answers the count with NULL problem, but I'm still a little confused about the question:</p> <pre><code>select count(*) from sys.indexes; -- 697 results go select count(isnull(name,'')) from sys.indexes; -- 697 results go select count(name) from sys.indexes; -- 567 results go </code></pre> <p>And this gets the count of records for the MIN <code>name</code> field (based on collation and SQL sort order of string fields):</p> <pre><code>select i.name ,subCnt.Cnt from (select min(name) as name from sys.indexes) as i join (select name, count(*) as Cnt from sys.indexes group by name) as subCnt on subCnt.name = i.name; </code></pre> <p>And this query explains the aggregate sort order and why the above query chooses the value returned in the <code>name</code> field:</p> <pre><code>select name, row_number() over (order by name) from sys.indexes order by name; </code></pre> <p>And this query shows my collation's (Latin1_General_BIN) sort order even when replacing NULLs with char(0x7E):</p> <pre><code>select coalesce(name,char(0x7e)) , row_number() over (order by coalesce(name,char(0x7e))) from sys.indexes order by 2; </code></pre> <p>And this shows the sort order difference between collations in SQL Server (which determines what is MIN or MAX in a string field):</p> <pre><code>declare @test table (oneChar char(1) collate Latin1_General_BIN , oneChar2 char(1) collate SQL_Latin1_General_CP1_CI_AS , varb varbinary) insert into @test (oneChar) select 'c' union all select '~' union all select 'P' union all select 'X' union all select 'q' union all select NULL update @test set varb = cast(isnull(oneChar,char(0x7E)) as varbinary), oneChar2 = oneChar select min(oneChar) from @test -- 'P' select min(oneChar2) from @test -- '~' select min(varb) from @test -- 0x50, the varbinary equivalent of oneChar </code></pre> <p>And if you want the count of all rows and you want the MIN() of the name without considering the NULLs (and not seeing a warning, for whatever reason), use this:</p> <pre><code>select i1.Cnt ,i2.name from (select count(*) as Cnt from sys.indexes) as i1 ,(select min(name) as name from sys.indexes where name is not null) as i2 </code></pre> <p>And whatever you do, certainly don't cast a whole field as a different collation just to do some filtering. This question belongs in the discussion forums, not as a simple question/answer. </p>
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    1. POIs converting everything to varbinary the correct way to compare character data?
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    1. UStommy_o
    1. UStommy_o
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    1. COAnswer `A` will change the semantics. `SELECT MIN(ISNULL(name,'')) from (SELECT 'Foo' UNION ALL SELECT NULL) T(name)` returns `''` even though it doesn't exist in the data.
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      1. USMartin Smith
    2. COEhh yeah, you're right. I guess I don't really understand what the OP is attempting to do.
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    3. COPer question "B" in the original post, I was attempting to get MIN to return the expected result, since in the SQL in #6 (as well as other SQL using various comparison operators that I tried), it does not. Try adding the MIN function to your second and third SQL statements in your answer (with or without the substring and/or varbinary, or using other comparison functions/operators). When the counts are right, the comparisons are wrong and vice-versa.
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      1. USRob at TVSeries.com
 

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