Addressing MySQL Error 1145: Resolving GRANT Statement Issues with Long Host or User Names

MySQL Error 1145 arises when you’re managing user permissions and encounter the message: “Error 1145 – SQLSTATE: 42000 (ER_GRANT_WRONG_HOST_OR_USER) The host or user argument to GRANT is too long.” This error indicates that the host or user value specified in a GRANT statement exceeds the maximum length allowed by MySQL.

Understanding Error 1145

MySQL has length limits for user and host names used in GRANT statements. According to the MySQL documentation, the maximum length for a user name is 32 characters, and the maximum length for a host name is 60 characters. If your GRANT statement includes a user or host name exceeding these limits, MySQL will not execute the statement and will return Error 1145.

Diagnosing Error 1145

To diagnose this issue, review the GRANT statement that resulted in the error and check the lengths of the user and host names. Ensure they are within the allowed limits.

Fixing Error 1145

Here are steps and examples to help you resolve Error 1145:

Step 1: Shorten the User or Host Name

If the user or host name exceeds the maximum length, you’ll need to shorten it.

Example of a problematic GRANT statement:

GRANT ALL PRIVILEGES ON database.* TO 'verylongusernameexceedinglimit'@'verylonghostnameexceedingthelimitofcharactersallowed';

Corrected GRANT statement:

GRANT ALL PRIVILEGES ON database.* TO 'username'@'hostname';

Ensure that the ‘username’ and ‘hostname’ do not exceed the 32 and 60 character limits, respectively.

Step 2: Use Wildcards for Host Names

If you need to specify multiple hosts with similar names, consider using wildcards instead of listing all host names.

Example using wildcards:

GRANT ALL PRIVILEGES ON database.* TO 'username'@'192.168.1.%';

This grants privileges to ‘username’ from any host in the ‘192.168.1.’ subnet.

Step 3: Review and Update Existing Users

If existing user or host names are too long, you’ll need to update them. Use the RENAME USER statement to change the user name to a shorter one.

Example of renaming a user:

RENAME USER 'verylongusernameexceedinglimit'@'hostname' TO 'newuser'@'hostname';

Step 4: Apply Best Practices for Naming Conventions

Implement naming conventions that keep user and host names concise and meaningful, ensuring they stay within the character limits imposed by MySQL.

Step 5: Use IP Addresses for Hosts

If host names are too long, consider using IP addresses instead, which are typically shorter.

Example using an IP address:

GRANT ALL PRIVILEGES ON database.* TO 'username'@'';


By carefully managing user and host names within MySQL’s character limits, you can avoid Error 1145 and maintain a secure and organized permission structure. Always verify the lengths of user and host names in your GRANT statements and consider using wildcards or IP addresses to keep names concise. With the right approach, you can effectively manage database permissions without encountering this error.

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