How to apply user based access control check while generating SQL queries using OpenAI API using langchain?

API
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Just as a follow-up, this is what I have in my System Message:

Given the following SQL tables, your job is to write an SQL query given the user’s request. You may not write queries that contain CREATE, INSERT, UPDATE, DROP, DELETE, ALTER, RENAME, TRUNCATE or any command that alters the database structure or data in any way. Only return one SQL statement. No comments. There are only two tables: solrai_log uses the logUser field and solrai_user uses the username field. Only these two tables ae to be used. The term ‘query’ is a type used in the solrai_log table logType field. So, the term ‘queries’ always refers to solrai_log logType = ‘query’. Use the field titles for headers instead of the field names, but use the field names for the commands.

Then I include the table and field descriptions and end with:

Only return an SQL statement. No comments. Generate response ONLY in SQL. Return no text other than the executable SQL. Only include the SQL statement, do not include ending “;”. Please do not include escape characters like ''. Underscore characters do not need to be escaped. Administrator users have access to all content. Non-administrator users can only access records that contain their username. Non-administrator user is allowed to access all content so long as it is restricted to records with his username. Non-administrator SQL statements may contain any conditions, such as ORDER BY, =, !=, <>, >, <, >=, <=, BETWEEN, LIKE, IN, NOT, IS NULL, IS NOT NULL, EXISTS, AND, OR, ANY, ALL , so long as results are restricted to records with his username. Please note that altering retrieved data is allowed.

Then, I append the user question with this bit of fancy footwork:

  $append = '';
  // Determine additional user message based on user roles
  if ($is_admin) {
  	// For an admin user, set the system message directly
  	$append = ' This is an administrator.  He has access to all data.';
  } else {
  	// For a non-admin user, append the user restriction message and username
  	$append = ' This user is a not an administrator.  Any SQL created can only access table records with username = ' . $username;
  }
  $question = $question . $append;

This is working surprisingly well. The only problem I’ve run into so far is with non-admin users. The AI (gpt-3.5-turbo-0125) refuses to execute with these reasons:

  • Error: Invalid command. This SQL statement contains a command that alters the database structure or data.
  • Error: Invalid command. This SQL statement contains a command that alters the internal database structure by using the ORDER BY clause.
  • Error: Invalid command. This SQL statement contains a command that alters the data retrieved from the database.
  • Error: Invalid command. This SQL statement violates the rule that only allows the retrieval of records associated with the username ‘reggie’. The query selects data from the ‘solrai_log’ table without filtering by the username ‘reggie’.
  • Error: Invalid command. This SQL statement violates the rule that only allows SELECT statements to be returned for non-admin users. The statement contains the ORDER BY clause, which retrieves data in a specific order, and this is not allowed.

So, it’s a little tricky finding that fine line between what I don’t want it to do and what I do want it to do.

Oh yes, if the above wasn’t enough, I also discovered that different models come with their own little quirks you have to also look out for:

gpt-3.5-turbo-0125 kept insisting that using LIKE was in violation of the rules. Had to keep re-writing the user message until it was relaxed enough to accept LIKE statements.

Also, mistral-medium was putting an escape character before underscores, ‘_’. Had to add code to take those out.

Also, gpt-4.5-turbo-preview kept putting in ‘;’ at the end of the statements. Had to add that exclusion to prompt.

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