In a previous thread about sqlite_schema, I commented that there *is* a case where SQLITE_SCHEMA does get raised as an error, although DRH said that this is not possible in version 3.x. It turns out that I was wrong. The scenario I described does raise an error, but it is not SQLITE_SCHEMA, it is SQLITE_ERROR, and thus it is more difficult to handle.
in short: if two processes are accessing the same database, and one modifies the schema, the other gets this error on first access. stranegely, this behavior can not be verified using the command line program, as it does not happen there. however, this probably has to do with how this particular program is using the API. I am using the library via the windows dll, and in this case the sqlite3_step function will return a value of SQLITE_ERROR when another process has modified the schema. when I try to retrieve an error description via sqlite3_errmsg(fdb), I get a message similar to "database schema has changed", however the error code returned was NOT SQLITE_SCHEMA,but SQLITE_ERROR. Clearly, this creates havoc in a multi-user environment, and my code does not have a neat way of handling it. Since the error is sqlite_error, the only indication that a retry would succeed is in the text description, and I would hate to have to issue retries based on the text content.. DRH, is this fixable ? shall I open a ticket ?
