SQL Server 2016

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CREATE TABLE DoingStuff (
  DoingStuffID int NOT NULL IDENTITY(1,1),
  TaskText varchar(20)
  );
CREATE STATISTICS BreakingStuff ON DoingStuff (TaskText) WITH FULLSCAN;
INSERT INTO DoingStuff (TaskText)
VALUES
('Who Cares'),
('Not today'),
('Not sure');
3 rows affected

SELECT DoingStuffID, TaskText FROM DoingStuff;


DoingStuffID
TaskText


1
Who Cares

2
Not today

3
Not sure


PRINT 'Modify the table''s column TaskText to allow varchar(50)'
Modify the table's column TaskText to allow varchar(50)


ALTER TABLE DoingStuff 
  ALTER COLUMN TaskText varchar(50);
SELECT DoingStuffID, TaskText FROM DoingStuff;


DoingStuffID
TaskText


1
Who Cares

2
Not today

3
Not sure


PRINT 'Modify the table''s column TaskText to varchar(40)'
Modify the table's column TaskText to varchar(40)


ALTER TABLE DoingStuff 
  ALTER COLUMN TaskText varchar(40);
Msg 5074 Level 16 State 1 Line 1
The statistics 'BreakingStuff' is dependent on column 'TaskText'.
Msg 4922 Level 16 State 9 Line 1
ALTER TABLE ALTER COLUMN TaskText failed because one or more objects access this column.

SELECT DoingStuffID, TaskText FROM DoingStuff;


DoingStuffID
TaskText


1
Who Cares

2
Not today

3
Not sure


PRINT 'Drop Statistics and then modify the table''s column TaskText to varchar(40)'
Drop Statistics and then modify the table's column TaskText to varchar(40)


DROP STATISTICS DoingStuff.BreakingStuff;
ALTER TABLE DoingStuff 
  ALTER COLUMN TaskText varchar(40);
SELECT DoingStuffID, TaskText FROM DoingStuff;


DoingStuffID
TaskText


1
Who Cares

2
Not today

3
Not sure