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[MSSQL] 랜덤 (무작위) Select


Select Top 10 * From 테이블명 Order by NEWID()


-- RAND() 난수 발생
select RAND() as rnd;
select convert(int, RAND()*100) as r1 -- 3자리 정수 추출 (0~999)
     , RIGHT(RAND(), 5)         as r2 --  임의의 5자리 숫자 추출

--정수형 난수
--최대값와 최소값을 포함할 때  
declare @max -- 최대값
declare @min -- 최소값
 
SELECT CONVERT(INT, ((@max + 1) - @min) * RAND()  + @min)

https://github.com/ngio/DB_query_mssql/blob/main/%EB%9E%9C%EB%8D%A4_select_NEWID_RAND.sql

 IF…ELSE IF…ELSE 

https://simplesqltutorials.com/if-elseif-else/

IF(<condition is true>)
BEGIN
<execute some code>
END
ELSE IF(<different condition is true>)
BEGIN
<execute some other code>
END
ELSE
BEGIN
<execute some other other code>
END

월의 마지막 날짜 구하기

SELECT EOMONTH('2020-09-09') AS result

SELECT DATEADD (DAY, -1, DATEADD (MONTH, DATEDIFF (MONTH, 0, '2020-09-09') + 1, 0)) AS result


SELECT DATEADD(MONTH, DATEDIFF(MONTH, 0, '2020-09-09') + 1, 0) - 1 AS result

DATEDIFF, DATEPART

SELECT DATEDIFF(DAY,   '2021-06-12', '2021-07-13') AS [일차이]
     , DATEDIFF(MONTH, '2021-06-12', '2021-07-13') AS [개월차이] 
     , DATEDIFF(YEAR,  '2021-06-12', '2021-07-13') AS [년차이]

LAG, LEAD

https://learn.microsoft.com/en-us/sql/t-sql/functions/lag-transact-sql?view=sql-server-ver16 

SELECT empno  
     , ename
     , job
     , sal
     , LAG(sal) OVER(PARTITION BY job ORDER BY job, sal) AS sal_prev
     , LEAD(sal) OVER(PARTITION BY job ORDER BY job, sal) AS sal_next
  FROM emp
 WHERE job IN ('MANAGER', 'ANALYST', 'SALESMAN')
 ORDER BY job, sal
 
 
 CREATE TABLE T (a INT, b INT, c INT);   
GO  
INSERT INTO T VALUES (1, 1, -3), (2, 2, 4), (3, 1, NULL), (4, 3, 1), (5, 2, NULL), (6, 1, 5);   
  
SELECT b, c,   
    LAG(2*c, b*(SELECT MIN(b) FROM T), -c/2.0) OVER (ORDER BY a) AS i  
FROM T;

https://learn.microsoft.com/en-us/sql/t-sql/functions/lead-transact-sql?view=sql-server-ver16 

CREATE TABLE T (a INT, b INT, c INT);   
GO  
INSERT INTO T VALUES (1, 1, -3), (2, 2, 4), (3, 1, NULL), (4, 3, 1), (5, 2, NULL), (6, 1, 5);   
  
SELECT b, c,   
    LEAD(2*c, b*(SELECT MIN(b) FROM T), -c/2.0) OVER (ORDER BY a) AS i  
FROM T;

명시적 값을 테이블의 ID 열에 삽입할 수 있도록 합니다.

https://github.com/ngio/DB_query_mssql/blob/main/SET_IDENTITY_INSERT.sql

USE AdventureWorks2012;  
GO  
-- Create tool table.  
CREATE TABLE dbo.Tool(  
   ID INT IDENTITY NOT NULL PRIMARY KEY,   
   Name VARCHAR(40) NOT NULL  
);  
GO  
-- Inserting values into products table.  
INSERT INTO dbo.Tool(Name)   
VALUES ('Screwdriver')  
        , ('Hammer')  
        , ('Saw')  
        , ('Shovel');  
GO  
  
-- Create a gap in the identity values.  
DELETE dbo.Tool  
WHERE Name = 'Saw';  
GO  
  
SELECT *   
FROM dbo.Tool;  
GO  
  
-- Try to insert an explicit ID value of 3;  
-- should return an error:
-- An explicit value for the identity column in table 'AdventureWorks2012.dbo.Tool' can only be specified when a column list is used and IDENTITY_INSERT is ON.
INSERT INTO dbo.Tool (ID, Name) VALUES (3, 'Garden shovel');  
GO  
-- SET IDENTITY_INSERT to ON.  
SET IDENTITY_INSERT dbo.Tool ON;  
GO  
  
-- Try to insert an explicit ID value of 3.  
INSERT INTO dbo.Tool (ID, Name) VALUES (3, 'Garden shovel');  
GO  
  
SELECT *   
FROM dbo.Tool;  
GO  
-- Drop products table.  
DROP TABLE dbo.Tool;  
GO

탭   : char(9)

select * from 테이블명

where 컬럼명 = char(9)

엔터값 : char(10) + char(13)

select * from 테이블명

where 컬럼명 = char(10) + char(13)

select 'a'+char(9)+'b'

select 'a'+char(13)+'b'

select 'a'+char(10)+'b'

엑셀출력 등을 하거나 화면에서 공백을 제거해야할 경우 공백이랑 엔터 같이 제껴야 한다.

탭까지 제낄 필요있으면 char(9) 추가

REPLACE( REPLACE(column,char(13),'' ), char(10), '')