[sql-server] mssql convert varchar to float

I have a field value productlength of 0.123. This is from a view and has a data type of varchar.

I need to convert it to a float or numeric value so as o perform math comparisons.

convert(float,productlength) and cast(productlength as float) both do not work.

error varchar cant be converted to float or somethiing liek that.

From what I have read varchar can simply not be converted to a numeric string?

Any clever ways around this?

DECLARE @INPUT VARCHAR(5) = '0.12',@INPUT_1 VARCHAR(5)='0.12x';
select CONVERT(float, @INPUT) YOUR_QUERY ,
case when isnumeric(@INPUT_1)=1 THEN CONVERT(float, @INPUT_1) ELSE 0 END AS YOUR_QUERY_ANSWERED

above will return values

however below query wont work

DECLARE @INPUT VARCHAR(5) = '0.12',@INPUT_1 VARCHAR(5)='0.12x';
select CONVERT(float, @INPUT) YOUR_QUERY ,
case when isnumeric(@INPUT_1)=1 THEN CONVERT(float, @INPUT_1) ELSE **@INPUT_1** END AS YOUR_QUERY_ANSWERED

as @INPUT_1 actually has varchar in it.

So your output column must have a varchar in it.

Use

Try_convert(float,[Value])

See https://raresql.com/2013/04/26/sql-server-how-to-convert-varchar-to-float/