MySQL选择从今年到去年的特定月份的所有行

Question

I'm creating a system for a school that needs to retrieve data from April of this year to June from last year.

I needed a query that can retrieve from this dates due to their school year always starts from June and end in April.

I tried selecting dates using Where clause.

"SELECT * FROM students WHERE year(c_date) = ? AND month(c_date) = ? AND c_occupation = 'Student'"

the question marks are use for java language which to prepare a statement using this code

pst=conn.prepareStatement(Sql);
            pst.setInt(1, year);
            pst.setInt(2, month);

I also tried this method but with this, I need to enter the date again after a year has pass.

SELECT users.* FROM users 
WHERE dateadded <= '2019-06-01' 
AND dateadded >= '2018-4-30'

I wanted it to automatically based on what today's year is.

So for example today is March 20, 2019. I should be able to return all the values from this day until June 1, 2018

Answer 1

Your code can be :

LocalDate from = LocalDate.now().minusYears(1); // 2018-04-29
LocalDate to = LocalDate.of(Year.now().getValue(), Month.JUNE, 1); // 2019-06-01

String sql = "SELECT * FROM students WHERE dateadded BETWEEN ? AND ? AND c_occupation = 'Student'";
pst = conn.prepareStatement(Sql);
pst.setObject(1, from);
pst.setObject(2, to);

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• LocalDate.now().minusYears(1); return the same day of last year
• LocalDate.of(Year.now().getValue(), Month.JUNE, 1); return the 1st June of the current year
• dateadded BETWEEN ? AND ? will select all between the from and to dates
• pst.setObject(1, from); if you are using JDBC 4+ you can set a LocalDate like so

---

Some references :

• MySQL: BETWEEN Condition
• java.time API

Answer 2

Your last method can be made to work using this approach

SELECT * FROM students 
WHERE dateadded BETWEEN (CONCAT(YEAR(NOW()), '-06-01') - INTERVAL 1 YEAR) AND CURDATE() 
AND c_occupation = 'Student';