Ép kiểu DATETIME thành DATE trong MySQL

Để ép DATETIME thành DATE, dùng hàm CAST().

Cú pháp:

select cast(yourColumnName as Date) as anyVariableName from yourTableName;

Tạo bảng:

mysql> create table ConvertDatetimeToDate
-> (
-> YourDatetime datetime
-> );
Query OK, 0 rows affected (0.95 sec)

Chèn dữ liệu datetime:

mysql> insert into ConvertDatetimeToDate values(date_add(now(),interval 1 day));
Query OK, 1 row affected (0.17 sec)
mysql> insert into ConvertDatetimeToDate values(date_add(now(),interval -1 day));
Query OK, 1 row affected (0.15 sec)
mysql> insert into ConvertDatetimeToDate values(date_add(now(),interval 1 year));
Query OK, 1 row affected (0.10 sec)
mysql> insert into ConvertDatetimeToDate values(date_add(now(),interval -1 year));
Query OK, 1 row affected (0.16 sec)

Hiển thị:

mysql> select *from ConvertDatetimeToDate;

Kết quả:

+---------------------+
| YourDatetime        |
+---------------------+
| 2018-11-28 16:12:50 |
| 2018-11-26 16:13:00 |
| 2019-11-27 16:13:13 |
| 2017-11-27 16:13:24 |
+---------------------+
4 rows in set (0.00 sec)

Ép kiểu sang DATE:

mysql> select cast(YourDatetime as Date) as OnlyDateDemo from ConvertDatetimeToDate;

Kết quả:

+--------------+
| OnlyDateDemo |
+--------------+
| 2018-11-28   |
| 2018-11-26   |
| 2019-11-27   |
| 2017-11-27   |
+--------------+
4 rows in set (0.00 sec)