Is there any circumstances where you would allow code with a  'SELECT * ' to go into production?

I believe this should NEVER happen.  There is a discussion that...

SELECT
    LEFT(Bname, CHARINDEX(' ', BName) - 1) AS BName,
    MAX(CASE WHEN BName LIKE '% Start%' THEN StartDate ELSE '' END) AS...

I don't know of a super-slick way to do this off the top of my head:

SELECT DISTINCT run_date, run_time, 
    CAST(CAST(run_date AS varchar(8)) +...

OOPS, SORRY, I did it back'ards.

SELECT [Profile ID]

FROM dbo.table_name

GROUP BY [Profile ID]

HAVING COUNT(DISTINCT [Customer ID]) =

(SELECT COUNT(DISTINCT [Customer ID]) FROM dbo.table_name)

SELECT [Customer ID]

FROM dbo.table_name

GROUP BY [Customer ID]

HAVING COUNT(DISTINCT [Profile ID]) = (SELECT COUNT(DISTINCT [Profile ID]) FROM dbo.table_name)

You should definitely switch the key order on the lookup table, i.e., not:

PRIMARY KEY CLUSTERED ( iid, cart_id )

but instead do this:

PRIMARY KEY CLUSTERED ( cart_id, iid )

You could also likely work around changing the db code using views, if changing the code is just too difficult to do quickly by hand.  Typically that doesn't cause performance...

Yes.

EXEC sys.sp_rename 'dbo.table_name.column_name', 'new_column_name', 'COLUMN'

for each table column that you want to rename.

OOPS, quite right, I should have used ">=" and "<" rather than "BETWEEN".

I have NOT uber-tuned this, just trying to get something that works (so many people here obsess over every microsecond).  If you have a lot of rows, more tuning might...

SELECT G.Gage_ID 'ID', G.Model_No 'Model', L.LocationName 'Room', D.GageDescriptionName 'Desc',C.Calibration_DateTime 'Cal', G.Gage_SN 'S/N', S.StatusName 'Status', C.NextDue 'Due'

FROM GAGETRAK.Gages G

JOIN GAGETRAK.Locations L ON G.StorageLocation_RID_FK=L.Location_RID

JOIN GAGETRAK.GageDescriptions D ON G.GageDescription_RID_FK=D.GageDescription_RID

JOIN GAGETRAK.Status S ON G.Status_RID_FK=S.Status_RID...

(Nested) loop joins are a concern, particularly if SQL doesn't properly estimate the number of...

If you select the query code, right-click on it, and then select "Display Estimated Execution Plan", you should see any recommended index

SELECT B.*, CASE WHEN A.ServerName IS NULL THEN 'Not present in Table A' 
    ELSE 'Present in Table A' END AS Comment
FROM TableB B
LEFT...

ALTER procedure db.ToolReduceLogFileSize
    @db_name nvarchar(128),
    @size_mb int = 1024
AS
SET NOCOUNT ON;
DECLARE @sql nvarchar(max);
SET @sql = 'USE [' + @db_name + '];...