Authentication Settings Modes of Operation HyperSQL has many modes of operation and features that allow it to be used in very different scenarios.
This document is retained as part of the historical record of SQLite. Modern programmers should refer to more up-to-date documentation on SQLite is available elsewhere on this website. The core interface is as follows: There are other interface functions available and described below but we will begin by describing the core functions shown above.
The first argument is the database name. The second argument is intended to signal whether the database is going to be used for reading and writing or just for reading. The third argument is a pointer to a string pointer. The calling function is responsible for freeing the memory when it has finished with it.
The name of an SQLite database is the name of a file that will contain the database. If the file does not exist, SQLite attempts to create and initialize it.
If the file is read-only due to permission bits or because it is located on read-only media like a CD-ROM then SQLite opens the database for reading only.
The entire SQL database is stored in a single file on the disk. But additional temporary files may be created during the execution of an SQL command in order to store the database rollback journal or temporary and intermediate results of a query. This pointer will be the first argument to all subsequent SQLite function calls that deal with the same database.
NULL is returned if the open fails for any reason. If a transaction is active when the database is closed, the transaction is rolled back.
This function requires 5 parameters as follows: A pointer to a callback function which is invoked once for each row in the result of a query. This argument may be NULL, in which case no callbacks will ever be invoked.
A pointer that is forwarded to become the first argument to the callback function. A pointer to an error string. Error messages are written to space obtained from malloc and the error string is made to point to the malloced space.
The calling function is responsible for freeing this space when it has finished with it. This argument may be NULL, in which case error messages are not reported back to the calling function.
The callback function is used to receive the results of a query. A prototype for the callback function is as follows: The second argument is the number of columns in the query result.
The third argument is an array of pointers to strings where each string is a single column of the result for that record. If the i-th parameter is an empty string, we will get: The default behavior is not to invoke the callback at all if the result set is empty.
The callback function should normally return 0.
But if something goes wrong it can return a different value to indicate the type of error. Here is a complete list of the return codes: This can only happen if there is a bug in the SQLite library.
SQLite allows two or more threads to read the database at the same time, but only one thread can have the database open for writing at the same time. Locking in SQLite is on the entire database. This could mean that there is no more space left on the disk. Corruption might occur due to a rogue process writing to the database file or it might happen due to a previously undetected logic error in of SQLite.
The latter should only happen due to a hardware or operating system malfunction. The latter case should only occur for databases that are larger than 2GB in size. If another process changes the schema, the command currently being processed will abort because the virtual machine code generated assumed the old schema.Oct 20, · Note: Today's entry is a technical article: it isn't funny.
At least not intentionally.
Update, Oct 20th I've added an Updates section, where I'll try to track significant responses, at least for a week or so. There are three entries so far.
Contents. Introduction; Three Great Schools of . If you are distributing a db file with your app and you want to write to it, you need to first copy it from the Bundle directory to the Documents grupobittia.com could do this when the app is first started or at another opportune time.
Chapter 1 Introduction. The Checker Framework enhances Javas type system to make it more powerful and useful.
This lets software developers detect and prevent errors in their Java programs. Originally posted by: chrisnei @grupobittia.com This has happened twice to me now, both times was with editing the joystick config.
The actual files to delete are the cache files in your personal FG directory. 电脑出现SQL error: attempt to write a readonly database的对话框,怎么也关不掉 所有软件都卸载了，还是不行啊，请求帮忙解决。 此话题已被锁定。.
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