Wednesday, October 19, 2016

Using JOIN in UPDATE Statement


CREATE TABLE Table1 (Col1 INT, Col2 INT, Col3 VARCHAR(100))
INSERT INTO Table1 (Col1, Col2, Col3)
SELECT 1, 11, 'First'
UNION ALL
SELECT 11, 12, 'Second'
UNION ALL
SELECT 21, 13, 'Third'
UNION ALL
SELECT 31, 14, 'Fourth'
GO
-- Create table2
CREATE TABLE Table2 (Col1 INT, Col2 INT, Col3 VARCHAR(100))
INSERT INTO Table2 (Col1, Col2, Col3)
SELECT 1, 21, 'Two-One'
UNION ALL
SELECT 11, 22, 'Two-Two'
UNION ALL
SELECT 21, 23, 'Two-Three'
UNION ALL
SELECT 31, 24, 'Two-Four'
GO
SELECT *
FROM Table1
SELECT *
FROM Table2
GO

UPDATE Table1
SET Col2 = t2.Col2,
Col3 = t2.Col3
FROM Table1 t1
INNER JOIN Table2 t2 ON t1.Col1 = t2.Col1
--WHERE t1.Col1 IN (21, 31)

SELECT *
FROM Table1
SELECT *
FROM Table2
GO

DROP TABLE Table1
DROP TABLE Table2