Error code 42501

A last-minute website error is always frustrating.

PostgreSQL database queries often end up in errors with code 42501.

This PostgreSQL error 42501 usually occurs when an underprivileged user queries a database. This can be tricky to troubleshoot.

That’s why we often get requests to fix PostgreSQL errors as a part of our Server Management Services.

Today, let’s have a look into the error 42501 and see how our Support Engineers fix it for our customers.

When does PostgreSQL error 42501 occur?

Before moving on to the error 42501, let’s first see more about PostgreSQL.

PostgreSQL is one of the versatile database management systems. It comes handy for developers to build applications, server administrators to protect data and so on. In other words, PostgreSQL is a highly extensible database system.

The error code 42501 denotes insufficient privilege for the database user. But, there can be many reasons that lead to this error.

1. Insufficient privilege for the user

Usually, the 42501 error occurs when a PostgreSQL user with insufficient privileges makes a query on a database.

This indicates that the database user executed an operation, for which the user has no rights.

For database management, the user needs enough rights over the database.

When one of our customers was trying to query a database table in a PostgreSQL tool like pgAdmin, it ended up in error 42501.

The error message was

By default, in the PostgreSQL database, the user restoring the database will have the database ownership. For instance, when restoring a database as the root user, all objects will be under root ownership. And if another user is running any query on this database, it shows the 42501 error.

2. SELinux setting

Sometimes, the SELinux setting in the server can also cause an insufficient privilege error.

SELinux is a security architecture that is a part of Linux kernel. In SELinux, access and transition rights of a user, application, process, and file are all defined. Thus, if SELinux is enabled it affects the user privileges then the database query can end up in a 42501 error.

Fix for 42501 permission denied error

When our customers approach us with this error, our Support Team first checks the reasons that cause this error. The major reasons are insufficient user privilege and SELinux settings.

Now, let’s see how our Support Team fixes this error.

1.Granting Privilege to a user

First and foremost, when a customer approaches us with a 42501 error, we check the database user privileges already given.

If the user lacks enough permission, then we change it accordingly.

Mostly, the user does not have privileges over the requested tables.

In this case, we give privileges to the user over the requested tables using the command.

GRANT SELECT ON table_name TO PUBLIC;

This command gives all privileges over the table to the public, hence anyone can use it.

But, some customers prefer giving privileges only to a few users.

In this case, to give table access only to certain users, we use the command.

GRANT SELECT ON table_name TO user_name;

After giving privileges to the user, our Support Team executes the query once again. This ensures that the error is fixed.

Similarly, if the root user restored the dump file, this can cause insufficient privilege for the database user.

That is, if the root user restores the database using pg_dump --no-owner then the root user who restored the database will have all privileges.

So, we always restore the database using the login of the desired user. Then, this user will have all privileges over the database.

2. Disabling SELinux

In some cases, the user has enough privilege over the database and still the database query show 42501 error. Here, the SELinux can be the reason causing the error.

After considering other security settings, our Support Team disables this feature using the command.

selinuxenabled && echo enabled || echo disabled

[Still having trouble in fixing PostgreSQL errors? – We will fix it for you.]

Conclusion

In short, the PostgreSQL error 42501 occurs mainly due to insufficient privileges for database user for running query. We saw how our Support Engineers fixed this error for our customers.

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Quick fix for PostgreSQL error 42501

by Sijin George | Sep 9, 2019

A last-minute website error is always frustrating.

PostgreSQL database queries often end up in errors with code 42501.

This PostgreSQL error 42501 usually occurs when an underprivileged user queries a database. This can be tricky to troubleshoot.

That’s why we often get requests to fix PostgreSQL errors as a part of our Server Management Services.

Today, let’s have a look into the error 42501 and see how our Support Engineers fix it for our customers.

When does PostgreSQL error 42501 occur?

Before moving on to the error 42501, let’s first see more about PostgreSQL.

PostgreSQL is one of the versatile database management systems. It comes handy for developers to build applications, server administrators to protect data and so on. In other words, PostgreSQL is a highly extensible database system.

The error code 42501 denotes insufficient privilege for the database user. But, there can be many reasons that lead to this error.

1. Insufficient privilege for the user

Usually, the 42501 error occurs when a PostgreSQL user with insufficient privileges makes a query on a database.

This indicates that the database user executed an operation, for which the user has no rights.

For database management, the user needs enough rights over the database.

When one of our customers was trying to query a database table in a PostgreSQL tool like pgAdmin, it ended up in error 42501.

The error message was

By default, in the PostgreSQL database, the user restoring the database will have the database ownership. For instance, when restoring a database as the root user, all objects will be under root ownership. And if another user is running any query on this database, it shows the 42501 error.

2. SELinux setting

Sometimes, the SELinux setting in the server can also cause an insufficient privilege error.

SELinux is a security architecture that is a part of Linux kernel. In SELinux, access and transition rights of a user, application, process, and file are all defined. Thus, if SELinux is enabled it affects the user privileges then the database query can end up in a 42501 error.

Fix for 42501 permission denied error

When our customers approach us with this error, our Support Team first checks the reasons that cause this error. The major reasons are insufficient user privilege and SELinux settings.

Now, let’s see how our Support Team fixes this error.

1.Granting Privilege to a user

First and foremost, when a customer approaches us with a 42501 error, we check the database user privileges already given.

If the user lacks enough permission, then we change it accordingly.

Mostly, the user does not have privileges over the requested tables.

In this case, we give privileges to the user over the requested tables using the command.

This command gives all privileges over the table to the public, hence anyone can use it.

But, some customers prefer giving privileges only to a few users.

In this case, to give table access only to certain users, we use the command.

After giving privileges to the user, our Support Team executes the query once again. This ensures that the error is fixed.

Similarly, if the root user restored the dump file, this can cause insufficient privilege for the database user.

That is, if the root user restores the database using pg_dump —no-owner then the root user who restored the database will have all privileges.

So, we always restore the database using the login of the desired user. Then, this user will have all privileges over the database.

2. Disabling SELinux

In some cases, the user has enough privilege over the database and still the database query show 42501 error. Here, the SELinux can be the reason causing the error.

After considering other security settings, our Support Team disables this feature using the command.

[Still having trouble in fixing PostgreSQL errors? – We will fix it for you.]

Conclusion

In short, the PostgreSQL error 42501 occurs mainly due to insufficient privileges for database user for running query. We saw how our Support Engineers fixed this error for our customers.

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Источник

Postgresql copy error 42501

All messages emitted by the PostgreSQL server are assigned five-character error codes that follow the SQL standard’s conventions for “ SQLSTATE ” codes. Applications that need to know which error condition has occurred should usually test the error code, rather than looking at the textual error message. The error codes are less likely to change across PostgreSQL releases, and also are not subject to change due to localization of error messages. Note that some, but not all, of the error codes produced by PostgreSQL are defined by the SQL standard; some additional error codes for conditions not defined by the standard have been invented or borrowed from other databases.

According to the standard, the first two characters of an error code denote a class of errors, while the last three characters indicate a specific condition within that class. Thus, an application that does not recognize the specific error code might still be able to infer what to do from the error class.

Table A.1 lists all the error codes defined in PostgreSQL 15.1. (Some are not actually used at present, but are defined by the SQL standard.) The error classes are also shown. For each error class there is a “ standard ” error code having the last three characters 000 . This code is used only for error conditions that fall within the class but do not have any more-specific code assigned.

The symbol shown in the column “ Condition Name ” is the condition name to use in PL/pgSQL . Condition names can be written in either upper or lower case. (Note that PL/pgSQL does not recognize warning, as opposed to error, condition names; those are classes 00, 01, and 02.)

For some types of errors, the server reports the name of a database object (a table, table column, data type, or constraint) associated with the error; for example, the name of the unique constraint that caused a unique_violation error. Such names are supplied in separate fields of the error report message so that applications need not try to extract them from the possibly-localized human-readable text of the message. As of PostgreSQL 9.3, complete coverage for this feature exists only for errors in SQLSTATE class 23 (integrity constraint violation), but this is likely to be expanded in future.

Table A.1. PostgreSQL Error Codes

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If you see anything in the documentation that is not correct, does not match your experience with the particular feature or requires further clarification, please use this form to report a documentation issue.

Источник

> > SELECT appid,hash 
>       FROM app
>       WHERE appid=1;

ERROR:  permission denied for relation app

********** Error **********

ERROR: permission denied for relation app
SQL state: 42501

4 ответа

Лучший ответ

CREATE ROLE myapp_readonly;
GRANT CONNECT ON DATABASE {database} TO myapp_readonly;
GRANT USAGE ON SCHEMA {schema} TO myapp_readonly;
GRANT SELECT ON TABLE {schema}.{table_name} TO myapp_readonly;
GRANT myapp_readonly TO {usre};

SQL Error [42501]: ERROR: permission denied for schema {schema}