world.DatabaseOpen

MUSHclient script function (Method) — introduced in version 4.40

Opens an SQLite database

Prototype

long DatabaseOpen(BSTR DbName, BSTR Filename, long Flags);

Data type meanings

Description

Opens or creates a database. Databases can be held in memory or on disk. You need read or write permissions to access the database, as it is stored on disk as a normal disk file.

DbName - a unique ID you choose to identify this database for all other operations on it (Eg. "db").

Filename - the file name on disk. The special filename ":memory:" opens an in-memory database. This can be used to manipulate data (or play with SQL) without actually writing to disk.

Flags -

Open_ReadOnly = 0x00000001
Open_ReadWrite = 0x00000002
Open_Create = 0x00000004
Open_DeleteOnClose = 0x00000008
Open_Exclusive = 0x00000010
Open_Main_db = 0x00000100
Open_Temp_db = 0x00000200
Open_Transient_db = 0x00000400
Open_Main_Journal = 0x00000800
Open_Temp_Journal = 0x00001000
Open_SubJournal = 0x00002000
Open_Master_Journal = 0x00004000
Open_NoMutex = 0x00008000
Open_FullMutex = 0x00010000

Warning - the SQLite documentation suggests that you choose one of:

Open_ReadOnly (1)
Open_ReadWrite (2) or
Open_ReadWrite + Open_Create (6)

If not, the behaviour of the open may be undefined.

Use DatabaseClose to close the database when you are finished with it.

If the database is still open when the world file is closed, the database is automatically closed.

It is not an error to re-open the same database ID of an existing, open, database, provided the disk file name is the same. This will be treated as a no-operation, so that triggers and aliases can open the database without having to check first if it was already open.

Lua example

DatabaseOpen ("db",   -- database ID
              GetInfo (66) .. "mytestdb.sqlite",   -- file name
              6)      -- flags

-- do stuff with the database here

DatabaseClose ("db")  -- close it

Lua notes

The Flags parameter can be omitted, and defaults to 6 (Open_ReadWrite + Open_Create).

The return codes are available in the sqlite3 table in Lua, as follows:

sqlite3.OK = 0
sqlite3.INTEGER = 1
sqlite3.INTERNAL = 2
sqlite3.PERM = 3
sqlite3.ABORT = 4
sqlite3.BUSY = 5
sqlite3.LOCKED = 6
sqlite3.NOMEM = 7
sqlite3.READONLY = 8
sqlite3.INTERRUPT = 9
sqlite3.IOERR = 10
sqlite3.CORRUPT = 11
sqlite3.NOTFOUND = 12
sqlite3.FULL = 13
sqlite3.CANTOPEN = 14
sqlite3.PROTOCOL = 15
sqlite3.EMPTY = 16
sqlite3.SCHEMA = 17
sqlite3.TOOBIG = 18
sqlite3.CONSTRAINT = 19
sqlite3.MISMATCH = 20
sqlite3.MISUSE = 21
sqlite3.NOLFS = 22
sqlite3.FORMAT = 24
sqlite3.RANGE = 25
sqlite3.NOTADB = 26
sqlite3.ROW = 100
sqlite3.DONE = 101

Return value

0 : success

-6 : Database already exists under a different disk name

Otherwise, an SQLite error code, and the database ID cannot be used

Related topic

Database (SQLite)

See also