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sqliterangerowid

Valid range of SQLite rowid?

I'm making a wrapper of SQLite C API. And I want to return rowid as integer type. To mark error case, I need a invalid value of the rowid. Is there invalid value of SQLite rowid? Or all values in signed 64bit integers are valid for rowid? (because if it is, I have to choose another way to implement marking error case)

Solution

  • Row IDs are 64-bit signed integers, so the maximum is 0x7FFFFFFFFFFFFFFFLL. But unless a negative or zero row ID has been entered explicitly, auto-generated row IDs are always greater than zero. If you can be certain that row IDs will always be generated automatically then zero or -1 would be safe values to for error status returns.

    Thinking further, I realise that the sqlite3_last_insert_rowid API call returns zero if nothing has ever been inserted into the table, thus making zero a de-facto "invalid" row ID.