Sum of all column name of specific string dates - mysql

Question

I have a table wherein I want to get the total prices of a column in specific dates. The dates are strings (eg: January 2018). What I have tried is to convert the string to date.
SELECT
SUM(price_amount) as 'total_paid',
STR_TO_DATE(CONCAT('01 ',price_month), "%M %d %Y") as dates
FROM user_prices
WHERE price_type = 'cash' AND price_month >= DATE('January 01 2018')
GROUP BY price_month
ORDER BY price_month DESC;
The result of this is null. I have to get only the sum of each existing month in the table that dates are equal or greater January 01 2018. And also group them by month.
email price_amount price_month price_type date_added
1#gmail.com 200 April 2017 cash ---
19#gmail.com 400 December 2017 cash ---
12#gmail.com 100 January 2018 cash ---
123#gmail.com 230 January 2018 cash ---
1234#gmail.com 250 January 2018 credit ---
321#gmail.com 200 April 2018 cash ---
32#gmail.com 120 March 2018 cash ---
So the example above should show the expected result below:
price_month total_paid
March 2018 120
April 2018 200
January 2018 330

Answer 1

If the price_month column is actually literal text as you have shown us, then you'll need to use STR_TO_DATE to make this query work. Note that STR_TO_DATE requires at least year, month, and day information in order to generate a date. So, in the query below, I arbitrarily build each month year data as occurring on the first of the month.
SELECT
price_month,
SUM(price_amount) AS total_paid
FROM user_prices
WHERE
STR_TO_DATE(CONCAT('01 ', price_month), '%d %M %Y') >= '2018-01-01' AND
price_type = 'cash'
GROUP BY
price_month,
STR_TO_DATE(CONCAT('01 ', price_month), '%d %M %Y')
ORDER BY
STR_TO_DATE(CONCAT('01 ', price_month), '%d %M %Y');
Demo
Moving forward, please don't store your dates as text like this. In general, you may assume that a puppy gets run over every time you have to use STR_TO_DATE in a MySQL query.