SQL Server – Cast VARCHAR to INT and Convert Values Under 0 to 0

Write your query this way. It includes a better test for integers and dumps ISNUMERIC that returns 1 for '-.', for example.

SELECT
    zip,
    coordinates
FROM (
    SELECT
        CASE WHEN ZIP5>'' AND NOT ZIP5 LIKE '%[^0-9]%' THEN
            CONVERT(int, [ZIP5]) END zip,
        CONVERT(varchar(max), geom) AS coordinates
    FROM 
        [SpatialData].[dbo].[zip5]
    WHERE
        ZIP5>'' AND NOT ZIP5 LIKE '%[^0-9]%'
) AS t1
WHERE
    zip >= 85000 AND
    zip < 86000

See this Connect item

SQL Server is free to evaluate the WHERE/SELECT clause in the order that it decides is optimized. A view or derived table is not materialized can easily be expanded into, from the outer query.

What SQL Server is compiling is really a query that looks like this

SELECT
    CONVERT(int, [ZIP5]) AS zip,
    CONVERT(varchar(max), geom) AS coordinates
FROM 
    [SpatialData].[dbo].[zip5]
WHERE
    ISNUMERIC([ZIP5]) = 1
    AND CONVERT(int, [ZIP5]) >= 85000
    AND CONVERT(int, [ZIP5]) < 86000

You can inspect the query plan of your original, but my guess from looking at the structure is that the WHERE clause uses the expression CONVERT(int, [ZIP5]) twice, so it makes sense to streamline the resolution (calculation to a result) of the expression in the process of retrieving data from the table. This puts the processing of the SELECT clause before the WHERE, so your ISNUMERIC() = 1 never got a chance to filter the bad eggs.

It is by-design.

This is not clear what output is needed. You are trying to convert text strings to int. This obviously does not work. Besides this type of formatting might fit better outside of SQL Server.

If you want something like 5 Hours 15 Minutes you can try this query:

[Time Spent(In hrs)] =
    CAST(
        SUM(
            DATEDIFF(hour, ld_time_tracker_start_time, ld_time_tracker_end_time)                     
        )
    as varchar(10))
    +' Hours '+ 
    CAST(
        SUM(
            DATEDIFF(minute, ld_time_tracker_start_time, ld_time_tracker_end_time) % 60       
        )
    as varchar(10))
+' Minutes'

Note that I have replaced HH by hour. This is easier to read and understand and it avoid mistakes. See DATEDIFF (Transact-SQL).