如何获取MySQL现有表中新增列的创建或更新时间？

Hey there! Let's work through this problem together. The bad news first: MySQL doesn't natively track column-level creation or modification timestamps for standard storage engines like InnoDB. But don't worry—there are a few workarounds to track down those changes, depending on your setup:

1. Check the Binary Logs (If Enabled) #

If your MySQL instance has binary logging turned on (which is common for replication or point-in-time recovery), it will log all DDL operations (like ALTER TABLE statements that add columns). Here's how to use it:

• Locate your binary log files (you can find their path with SHOW VARIABLES LIKE 'log_bin%';)
• Use the mysqlbinlog tool to parse logs from a time range you suspect the changes were made:

  mysqlbinlog --start-datetime="YYYY-MM-DD HH:MM:SS" --stop-datetime="YYYY-MM-DD HH:MM:SS" /path/to/binlog.00000X | grep -i "alter table"
  

• This will spit out all ALTER TABLE commands from that window, including the exact time they ran and which columns were added. Just note: if your binlogs are rotated and older logs have been deleted, this won't work.

2. Compare Local and Production Table Schemas #

Since you have the modified local database, you can directly compare its table structure to the production one to identify new columns, then cross-reference with your own operational timeline:

• Export the schema (no data) for the modified tables from your local DB:

  mysqldump -u your_local_user -p --no-data your_local_db your_table > local_schema.sql
  

• Do the same for the production DB:

  mysqldump -u prod_user -p --no-data prod_db your_table > prod_schema.sql
  

• Use a diff tool to spot differences:

  diff local_schema.sql prod_schema.sql
  

• The output will show exactly which columns are new in your local setup. You can then check your shell history (if you used the command line) or recall when you made those changes to get a timestamp.

3. Use Table-Level Update Timestamps (As a Reference) #

While this doesn't give you column-specific times, you can get the last time the table was modified (which would coincide with when you added columns) from the information_schema database:

SELECT TABLE_NAME, UPDATE_TIME 
FROM information_schema.TABLES 
WHERE TABLE_SCHEMA = 'your_local_db';

This UPDATE_TIME reflects the last DDL change or data modification on the table—so if you added columns recently, this can narrow down the time window.

4. Check Audit Logs (If You're Using MySQL Enterprise) #

If you have MySQL Enterprise Edition with the Audit Log plugin enabled, all DDL operations are logged with timestamps and user information. You can directly query the audit log files to find the exact ALTER TABLE commands and their execution times.

内容的提问来源于stack exchange，提问作者Kedar Limaye