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Delete column from SQLite table
... TRANSACTION;
CREATE TEMPORARY TABLE t1_backup(a,b);
INSERT INTO t1_backup SELECT a,b FROM t1;
DROP TABLE t1;
CREATE TABLE t1(a,b);
INSERT INTO t1 SELECT a,b FROM t1_backup;
DROP TABLE t1_backup;
COMMIT;
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Why is SELECT * considered harmful?
Why is SELECT * bad practice? Wouldn't it mean less code to change if you added a new column you wanted?
15 Answers
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Check if a temporary table exists and delete if it exists before creating a temporary table
...me in SQL Server 2005, with the extra "foo" column appearing in the second select result:
IF OBJECT_ID('tempdb..#Results') IS NOT NULL DROP TABLE #Results
GO
CREATE TABLE #Results ( Company CHAR(3), StepId TINYINT, FieldId TINYINT )
GO
select company, stepid, fieldid from #Results
GO
ALTER TABLE #R...
SQL - find records from one table which don't exist in another
...shortest statement, and may be quickest if your phone book is very short:
SELECT *
FROM Call
WHERE phone_number NOT IN (SELECT phone_number FROM Phone_book)
alternatively (thanks to Alterlife)
SELECT *
FROM Call
WHERE NOT EXISTS
(SELECT *
FROM Phone_book
WHERE Phone_book.phon...
SQL variable to hold list of integers
...e @listOfIDs table (id int);
insert @listOfIDs(id) values(1),(2),(3);
select *
from TabA
where TabA.ID in (select id from @listOfIDs)
or
declare @listOfIDs varchar(1000);
SET @listOfIDs = ',1,2,3,'; --in this solution need put coma on begin and end
select *
from TabA
where charindex(',' + C...
Create a date from day month and year with T-SQL
...are @Year Integer Set @Year = 2006
-- ------------------------------------
Select DateAdd(day, @DayOfMonth - 1,
DateAdd(month, @Month - 1,
DateAdd(Year, @Year-1900, 0)))
It works as well, has added benefit of not doing any string conversions, so it's pure arithmetic proce...
WITH CHECK ADD CONSTRAINT followed by CHECK CONSTRAINT vs. ADD CONSTRAINT
...CREATE TABLE T2 (FKID INT, SomeOtherVal CHAR(2));
INSERT T1 (ID, SomeVal) SELECT 1, 'A';
INSERT T1 (ID, SomeVal) SELECT 2, 'B';
INSERT T2 (FKID, SomeOtherVal) SELECT 1, 'A1';
INSERT T2 (FKID, SomeOtherVal) SELECT 1, 'A2';
INSERT T2 (FKID, SomeOtherVal) SELECT 2, 'B1';
INSERT T2 (FKID, SomeOtherVal...
How to check if a Constraint exists in Sql server?
...
try this:
SELECT
*
FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS
WHERE CONSTRAINT_NAME ='FK_ChannelPlayerSkins_Channels'
-- EDIT --
When I originally answered this question, I was thinking "Foreign Key" because the o...
Sublime - delete all lines containing specific value
...e got stuck for several minutes when I did Ctrl+Shift+K with 200,000 lines selected.
– Przemek D
Aug 28 '17 at 11:43
I...
How to get all options of a select using jQuery?
How can I get all the options of a select through jQuery by passing on its ID?
17 Answers
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