SQL Challenges-1: Find the first login date for each customer

Last update on December 20 2024 11:58:47 (UTC/GMT +8 hours)

From the following table, write a SQL query to find the first login date for each customer. Return customer id, login date.

Input:

Table: bank_trans

Structure:

Data:

Sample Solution:

SQL Code(MySQL):

DROP TABLE IF EXISTS bank_trans;
CREATE TABLE bank_trans(trans_id int, customer_id int, login_date date);
INSERT INTO bank_trans VALUES (101, 3002, '2019-09-01');
INSERT INTO bank_trans VALUES (101, 3002, '2019-08-01');
INSERT INTO bank_trans VALUES (102, 3003, '2018-09-13');
INSERT INTO bank_trans VALUES (102, 3002, '2018-07-24');
INSERT INTO bank_trans VALUES (103, 3001, '2019-09-25');
INSERT INTO bank_trans VALUES (102, 3004, '2017-09-05');
SELECT * FROM bank_trans;

SELECT customer_id, MIN(login_date) first_login
FROM bank_trans
GROUP BY customer_id;

Sample Output:

customer_id|first_login|
-----------|-----------|
       3001| 2019-09-25|
       3002| 2018-07-24|
       3003| 2018-09-13|
       3004| 2017-09-05|

SQL Code Editor:

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