SQL Server Calculation – How to Perform Calculations with VARCHAR

sql serversql-server-2008-r2t-sql

I am attempting to do a calculation in SQL Server 2008 R2 but I keep getting an error of

Msg 245, Level 16, State 1, Line 10
Conversion failed when converting the varchar value '.05' to data type int.

Altering table structure is not an option, is there a way I can alter the query so that this will succesfully execute?

DECLARE @Test1 TABLE
(
  field1 VARCHAR(10),
  field2 INT
);

INSERT INTO @Test1 ( field1, field2 )
    VALUES ( '.05', 12 );

SELECT field1 / field2 
FROM @Test1;

Best Answer

Is this what you want to happen?

DECLARE @Test1 TABLE
(
  field1 VARCHAR(10),
  field2 INT
);

INSERT INTO @Test1 ( field1, field2 )
    VALUES ( '.05', 12 );

SELECT field1 / CONVERT(DECIMAL(18, 2), field2)
    FROM @Test1;

Since this was marked as the answer: I converted the integer value to a decimal because of data type precedence. The string '.05' can't be converted to an integer, but it makes a perfectly fine decimal.

Related Solutions

Sql-server – Query to convert the count to million or thousands

This type of formatting is generally best done in your application if possible.

The problem is that the case expression returns a result based on the highest datatype precedence of any branch.

So you would need to cast the final COUNT branch of your CASE to VARCHAR too as int has higher precedence than varchar.

Also you should probably add year into your order by except if you actually want to order Jan 2014 and Jan 2015 together followed by Feb and so on.

Though I might well be minded to take that concatenated string out of the GROUP BY too and rewrite it (Along the way fixing a couple of other issues with integer division and inconsistent boundary conditions) as.

WITH T(mmmyyyy, FORMATTED_COUNT, Yr, Mnth)
     AS (SELECT DATENAME(MONTH, MIN(CREATEDTS)) + ', ' + DATENAME(YEAR, MIN(CREATEDTS)) AS Month,
                CASE
                  WHEN COUNT(*) BETWEEN 1000 AND 999999
                    THEN ( CONVERT (VARCHAR(10), ( CAST(ROUND(COUNT(*) / 1000.0, 1) AS NUMERIC(4, 1)) )) ) + 'k'
                  WHEN COUNT(*) >= 1000000
                    THEN ( CONVERT (VARCHAR(10), ( CAST(ROUND(COUNT(*) / 1000000.0, 2) AS NUMERIC(6, 2)) )) ) + 'm'
                  ELSE CONVERT (VARCHAR(10), COUNT(*))
                END,
                YEAR(CREATEDTS),
                MONTH(CREATEDTS)
         FROM   USAGEDATA
         GROUP  BY YEAR(CREATEDTS),
                   MONTH(CREATEDTS))
SELECT mmmyyyy,
       FORMATTED_COUNT
FROM   T
ORDER  BY Yr,
          Mnth;

SQL Server – How to Convert VARCHAR to DATETIME Format

There is too much precision in the varchar to be converted into datetime.

One option(better in my opinion) would be to change the target column to datetime2(7). Then you can convert like this:

declare @dt varchar(50)
set @dt = '2015-12-02 20:40:37.8130000'

select cast(@dt as datetime2(7));

If changing the column is not an option the you can do the conversion like this:

declare @dt varchar(50)
set @dt = '2015-12-02 20:40:37.8130000'

select cast(cast(@dt as datetime2(7))as datetime)

Best Answer

Related Solutions

Sql-server – Query to convert the count to million or thousands

SQL Server – How to Convert VARCHAR to DATETIME Format

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