mysql time modification

Mysql is a relational database management system that is suitable for various types of data collections, ranging from simple personal applications to large-scale enterprise-level data warehouses and commercial websites. In Mysql, timestamp (Timestamp) is a very common data type and is widely used in timestamp storage and query.

However, in actual applications, we sometimes encounter situations where we need to modify the timestamp in the database, for example, we need to modify the timestamp of a certain record to the current timestamp or a specified timestamp. So how to modify the timestamp in Mysql? This article will introduce in detail the following aspects:

1. Introduction to Mysql timestamp
2. Modify the timestamp to the current timestamp
3. Modify the timestamp to the specified timestamp
4. Summary

1. Introduction to Mysql timestamp

In Mysql, timestamp (Timestamp) is a data type that represents the specific time when an event occurs. . It is often used to record the creation time and update time of data, as well as other time-related operations.

Time stamps in Mysql come in two different formats: Unix timestamp and Mysql timestamp.

Unix timestamp refers to the number of seconds that have elapsed from 0:00:00 on January 1, 1970 to the current time. This format of timestamp is called Unix Timestamp in Mysql. It can use Mysql's built-in UNIX_TIMESTAMP() function to convert datetime type time data into a Unix timestamp, for example:

SELECT UNIX_TIMESTAMP(NOW()); //Get the current Unix timestamp

Mysql timestamp is a timestamp represented in YYYY-MM-DD HH:MI:SS format. It can use Mysql's built-in NOW() function to get the current timestamp, for example:

SELECT NOW(); //Get the current Mysql timestamp

In addition, Mysql also provides FROM_UNIXTIME() The function can convert Unix timestamp to Mysql timestamp, for example:

SELECT FROM_UNIXTIME(1602590500); //Convert Unix timestamp 1602590500 to Mysql timestamp

2. Modify the timestamp to Current timestamp

Sometimes, we need to change the timestamp of a record in the database to the current timestamp. In Mysql, you can use the NOW() function to get the current timestamp, and then use the UPDATE statement to update the timestamp field of the corresponding record to the current timestamp, for example:

UPDATE table_name SET timestamp_field = NOW() WHERE id = 1;

Among them, table_name is the table name, timestamp_field is the timestamp field name, and id is the primary key value of the target record.

If you need to batch update the timestamps of multiple records to the current timestamp, you can use the UPDATE statement combined with conditional statements, for example:

UPDATE table_name SET timestamp_field = NOW() WHERE condition;

Among them, condition is a conditional statement for filtering records that need to be updated. For example, if you need to update the timestamp field of all records with status 1, you can use the following statement:

UPDATE table_name SET timestamp_field = NOW() WHERE status = 1;

3. Modification time Stamp to the specified timestamp

In addition to changing the timestamp to the current timestamp, sometimes it is also necessary to change the timestamp of a certain record to the specified timestamp. In Mysql, you can use the DATE_FORMAT() function to convert the specified time string into a Mysql timestamp, for example:

SELECT DATE_FORMAT('2020-10-13 18:03:00', '%Y- %m-%d %H:%i:%s'); //Convert the time string to a Mysql timestamp

Then, you can use the UPDATE statement to update the timestamp field of the corresponding record to the specified Timestamp, for example:

UPDATE table_name SET timestamp_field = '2020-10-13 18:03:00' WHERE id = 1;

where, '2020-10-13 18:03 :00' is the specified timestamp string, table_name is the table name, timestamp_field is the timestamp field name, and id is the primary key value of the target record.

If you need to batch update the timestamps of multiple records to a specified timestamp, you can also use the UPDATE statement combined with conditional statements, for example:

UPDATE table_name SET timestamp_field = '2020-10- 13 18:03:00' WHERE condition;

where condition is a conditional statement for filtering records that need to be updated. For example, if you need to update the timestamp field of all records with status 1 to 2020-10-13 18:03:00, you can use the following statement:

UPDATE table_name SET timestamp_field = '2020-10-13 18 :03:00' WHERE status = 1;

4. Summary

Time stamp in Mysql is a common data type and is widely used in timestamp storage, query and calculation. In practical applications, sometimes it is necessary to modify the timestamp in the database, such as changing the timestamp to the current timestamp or a specified timestamp. You can use the corresponding Mysql functions and operations to modify the timestamp, such as the NOW() function to obtain the current timestamp, the DATE_FORMAT() function to convert a string into a Mysql timestamp, and the UPDATE statement to update the timestamp field. Mastering these operations can better use Mysql to manage timestamp data.

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