CAST numeric to varchar is giving scientific notation - casting

Question

I have three fields that I am trying to concatenate into one large field. Two of the fields are varchar, but one is a float. In certain situations, the concatenated field is showing scientific notation. The concatenated field should be a varchar and show the combination of the three fields regardless of how they are formatted. I am even seeing scientific notation when I just concatenate the two varchar fields when the values have all numbers in them. Why is this occurring and how can I fix it? Here are some examples of ways I am trying to do the concatenation:
Field1 = e.DocumentNo + e.Assignment + CAST(CAST([Amount in LC] as int) as nvarchar(50))
Field2 = CAST(e.DocumentNo + e.Assignment as varchar(255))
I have also tried using CONVERT and it does not provide the expected result. DocumentNo is a varchar(255) and Assignment is a varchar(255), yet when I have these values for each, 5115146916 and 1610000 respectively, Field2 looks like 5.11515E+16.
I also tried to use CONCAT() with the fields and it produces the same undesired result.

Answer 1

Here you go:
IF OBJECT_ID('TEMPDB..#ConcatData','U') IS NOT NULL
DROP TABLE #ConcatData;
CREATE TABLE #ConcatData(
[Amount in LC] [float] NULL,
[Assignment] [varchar](255) NULL,
[DocumentNo] [varchar](255) NULL)
INSERT INTO #ConcatData
VALUES
(-27.08, '20120295', '4820110172'),
(10625451.5124, '20140701', '4810122475'),
(205.5, 'TPE035948900001', '8200022827'),
(10000000, 'TPE035948900001', '8200022827')
SELECT DOCUMENTNO +
ASSIGNMENT +
CASE WHEN RIGHT(str([amount in lc],50,4),4) = '0000'
THEN ltrim(LEFT(str([amount in lc],50,4),LEN(str([amount in lc],50,4))-5))
WHEN RIGHT(str([amount in lc],50,4),3) = '000'
THEN ltrim(LEFT(str([amount in lc],50,4),LEN(str([amount in lc],50,4))-3))
WHEN RIGHT(str([amount in lc],50,4),2) = '00'
THEN ltrim(LEFT(str([amount in lc],50,4),LEN(str([amount in lc],50,4))-2))
WHEN RIGHT(str([amount in lc],50,4),1) = '0'
THEN ltrim(LEFT(str([amount in lc],50,4),LEN(str([amount in lc],50,4))-1))
ELSE ltrim(str([amount in lc],50,4))
END
FROM #ConcatData
Moral of the story here, float isn't the right datatype for your column. I actually don't know when float is the right datatype...
Anyway, the obnoxious CASE statement is needed to remove excess decimal-place zeroes caused by STR(). You might even need more, but this covers you up to 4 decimal places and I think you'll get the idea.
One note, the first THEN removes 5 chars instead of 4. This is to include the . as well.
Output:
482011017220120295-27.08
48101224752014070110625451.5124
8200022827TPE035948900001205.5
8200022827TPE03594890000110000000