Convert INT to VARCHAR SQL

Use the convert function.

SELECT CONVERT(varchar(10), field_name) FROM table_name

Use the STR function:

SELECT STR(field_name) FROM table_name

Arguments

float_expression

Is an expression of approximate numeric (float) data type with a decimal point.

length

Is the total length. This includes decimal point, sign, digits, and spaces. The default is 10.

decimal

Is the number of places to the right of the decimal point. decimal must be less than or equal to 16. If decimal is more than 16 then the result is truncated to sixteen places to the right of the decimal point.

source: https://msdn.microsoft.com/en-us/library/ms189527.aspx

You can use CAST function:

SELECT CAST(your_column_name AS varchar(10)) FROM your_table_name

Actually you don't need to use STR Or Convert. Just select 'xxx'+LTRIM(ColumnName) does the job. Possibly, LTRIM uses Convert or STR under the hood.

LTRIM also removes need for providing length. It seems to be working for integer or float without worry of truncation.

SELECT LTRIM(ColumnName) FROM TableName

also, LTRIM is better than STR as

SELECT STR(1234567890.123) 

gives 1234567890 whereas

SELECT LTRIM(1234567890.123) 

gives 1234567890.123