SQL Server Team-based Development - Red Gate Software

*
Populate the table with 100000 rows with random GUID
values. We'll overwrite them with the update anyway
*/
INSERT INTO #LoopingIsBad
( OurData
)
SELECT TOP 100000
NEWID()
FROM master..spt_values t1
CROSS JOIN master..spt_values t2
GO
Listing 11-12: Creating and populating the #LoopingIsBad temporary test table.
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Chapter 11: SQL Refactoring
Let's say we need to update the OurData column, based on the following complex
UPDATE rules.
1. If OurData value contains the substring ABCD, replace it with ABCD only.
2. If OurData value starts with E or F, replace it with E and F, respectively, plus
today's date.
3. If OurData value ends with 1, 2, 3, or 4 replace the value with 1, 2, 3, or 4 accordingly
(so, for example, abc1 would become 1, bfd2 would become 2, and so on).
4. If OurData value ends with 5 or 6 replace it with NULL.
5. For any other values, don't change the value.
Listing 11-13 shows the cursor-based approach, which is the first (and only) one considered
by many developers.