How to Use UPDATE Statements for Data Management using snowflake
Join us as we delve into the powerful capabilities of Snowflake's UPDATE statements, enabling you to efficiently manage and modify data within your Snowflake data warehouse. Whether you're a seasoned data professional or just starting your journey, this comprehensive tutorial provides step-by-step guidance to harness the full potential of Snowflake's data manipulation features. Learn practical tips, best practices, and real-world examples to streamline your data management processes and maximize the value of your Snowflake environment. Watch now and unlock new levels of data agility with Snowflake's UPDATE statements.
------------
SQL
-------------------------------------
-- update statement
-- modify existing value in a table
/*
syntax:
update table_name
set column_name = value [,column = value , ...]
[where condition];
*/
-- use the primary key column in the where clause to identify a single row for update.
--using other columns might accidentally update multiple row
CREATE OR REPLACE TABLE employees (
employee_id INT,
first_name VARCHAR(50),
last_name VARCHAR(50),
salary int,
department VARCHAR(50),
email VARCHAR(100)
);
INSERT INTO employees (employee_id, first_name, last_name, salary, department, email)
VALUES
(1, 'John', 'Doe', 60000, 'HR', '[email protected]'),
(2, 'Jane', 'Smith', 55000, 'Marketing', '[email protected]'),
(3, 'Michael', 'Smith', 65000, 'Engineering', '[email protected]'),
(4, 'Emily', 'Brown', 58000, 'Finance', '[email protected]'),
(5, 'David', 'Wilson', 62000, 'HR', '[email protected]'),
(6, 'Sarah', 'Taylor', 57000, 'Marketing', '[email protected]'),
(7, 'Matthew', 'Anderson', 68000, 'Engineering', '[email protected]'),
(8, 'Jessica', 'Martinez', 59000, 'Finance', '[email protected]'),
(9, 'Christopher', 'Hernandez', 63000, 'HR', '[email protected]'),
(10, 'Amanda', 'Robinson', 60000, 'Marketing', '[email protected]');
SELECT * FROM employees ;
UPDATE employees
SET department = 'Marketing'
WHERE employee_id = 1;
SELECT * FROM employees;
UPDATE employees
SET department = 'Marketing'
WHERE last_name = 'Smith';
SELECT * FROM employees;
-- You can change more than one column at same time.
UPDATE employees
SET SALARY =50000 , DEPARTMENT ='Finance'
WHERE EMPLOYEE_ID=5;
SELECT * FROM employees;
-- in update , you can set the column to null value
UPDATE employees
SET DEPARTMENT=NULL
WHERE EMPLOYEE_ID=3;
SELECT * FROM employees;
-- Subquery
-- Make Employee id 1's salary the same as Employee id 2's salary
UPDATE employees
SET salary=(select salary from employees where EMPLOYEE_ID=2)
WHERE EMPLOYEE_ID=1;
SELECT * FROM employees;
-- If you don't specify a condition, the update will affect all the rows in the table
UPDATE employees
SET SALARY =24100;
SELECT * FROM employees;
----------------------------------
#Snowflake #DataManagement #UPDATEStatement #DataManipulation #DataWarehousing #DataAgility #SQL #Tutorial #DataProfessionals #TechTutorial #DataAnalysis #DataScience #CloudComputing