Laravel入门遇MySQL错误：指定DEFINER用户'mysql.infoschema'@'localhost'不存在

Hey there, I’ve run into this exact definer error before with Homebrew-installed MySQL on older macOS versions, so let’s walk through how to fix it step by step:

Step 1: Stop the MySQL service first #

First, we need to shut down MySQL to make changes safely:

brew services stop mysql

If that doesn’t work (e.g., older Homebrew setup), try:

mysql.server stop

Step 2: Start MySQL in safe mode (skip permission checks) #

This lets us log in without needing valid credentials to fix the missing user:

mysqld_safe --skip-grant-tables &

The & runs it in the background so you can keep using the same terminal window.

Step 3: Log into MySQL without a password #

Now connect to the MySQL server as root, no password required:

mysql -u root

Step 4: Create the missing mysql.infoschema user and set permissions #

Run these SQL commands one by one inside the MySQL prompt:

-- Create the infoschema user (empty password is default for this system user)
CREATE USER 'mysql.infoschema'@'localhost' IDENTIFIED BY '';

-- Grant necessary SELECT permissions (this user only needs to read schema info)
GRANT SELECT ON *.* TO 'mysql.infoschema'@'localhost';

-- Refresh permissions to apply changes immediately
FLUSH PRIVILEGES;

Step 5: Exit MySQL and stop the safe-mode process #

Type exit; to leave the MySQL prompt, then kill the safe-mode MySQL process:

pkill mysqld

Step 6: Restart MySQL normally #

Start the service back up using Homebrew:

brew services start mysql

Step 7: Test if the error is gone #

Log into MySQL again (use your root password if you have one set):

mysql -u root -p

Then run the command that was failing before:

SHOW DATABASES;

This should now work without the definer error.

If the above steps don’t work (nuclear option: reinitialize MySQL) #

Warning: This will delete all your existing databases. Back up your data first!

1. Stop the service:

   brew services stop mysql
   

2. Back up your MySQL data directory:

   cp -r /usr/local/var/mysql /usr/local/var/mysql_backup
   

3. Find your installed MySQL version with:

   brew info mysql
   

   Look for a line like usr/local/Cellar/mysql/8.0.36 – that’s your --basedir path.
4. Initialize a fresh MySQL instance:

   mysqld --initialize --user=mysql --basedir=/usr/local/Cellar/mysql/[YOUR_VERSION] --datadir=/usr/local/var/mysql
   

5. Start the service:

   brew services start mysql
   

6. Find the temporary root password in the error log:

   cat /usr/local/var/mysql/$(hostname).err | grep temporary password
   

7. Log in with that temporary password, then set a new root password:

   ALTER USER 'root'@'localhost' IDENTIFIED BY 'your-new-password';
   

   After this, you can restore your backed-up databases if needed.

Why this happens #

This error usually pops up when MySQL is updated via Homebrew, and the automatic upgrade process fails to create or update the system-level mysql.infoschema user (which is critical for querying database schemas). Manually creating the user fixes the permission mismatch that’s causing the error.

内容的提问来源于stack exchange，提问作者jdubtd10