![]() In this article, we’ll outline what is SQLite, how to install the latest version, and ways to manage databases using the software. Which can be used as, for example: for row in query('my.SQLite is an incredibly popular open-source database engine which is used in applications of all kinds. Libsqlite3.sqlite3_column_name(pp_stmt, i).decode()įor i in range(0, libsqlite3.sqlite3_column_count(pp_stmt))Įxtract(pp_stmt, i)įor i in range(0, len(row_constructor._fields)) Run_with_db(db, bind, pp_stmt, i + 1, param) Run_with_db(db, libsqlite3.sqlite3_finalize, pp_stmt) Run_with_db(db, libsqlite3.sqlite3_prepare_v3, db, sql.encode(), -1, 0, byref(pp_stmt), None) Run_with_db(db, libsqlite3.sqlite3_close, get_pp_stmt(db, sql): Run(libsqlite3.sqlite3_open_v2, db_file.encode(), byref(db), SQLITE_OPEN_READWRITE, None) Raise Exception(libsqlite3.sqlite3_errstr(res).decode()) Libsqlite3.sqlite3_column_bytes(pp_stmt, i), Libsqlite3.sqlite3_column_blob(pp_stmt, i), Type(None): lambda pp_stmt, i, _: libsqlite3.sqlite3_bind_null(pp_stmt, i), Type(b''): lambda pp_stmt, i, value: libsqlite3.sqlite3_bind_blob(pp_stmt, i, value, len(value), SQLITE_TRANSIENT), Type(''): lambda pp_stmt, i, value: libsqlite3.sqlite3_bind_text(pp_stmt, i, value.encode('utf-8'), len(value.encode('utf-8')), SQLITE_TRANSIENT), Type(0.0): libsqlite3.sqlite3_bind_double, Libsqlite3.sqlite3_column_bytes.restype = c_int64 Libsqlite3.sqlite3_column_blob.restype = c_void_p Libsqlite3.sqlite3_column_int64.restype = c_int64 Libsqlite3.sqlite3_column_double.restype = c_double Libsqlite3.sqlite3_column_name.restype = c_char_p Libsqlite3.sqlite3_errmsg.restype = c_char_p Libsqlite3.sqlite3_errstr.restype = c_char_p The below defines a (generator) function, query from contextlib import contextmanagerįrom ctypes import cdll, byref, string_at, c_char_p, c_int, c_double, c_int64, c_void_p But in the functions above, defaults get correct behavior so I've skipped this (otherwise important) step.īased on ead's answer, this is a more complete example of how to use libsqlite3 from Python, which is also at This is somewhat quick and dirty: usually one needs to set argument-types and return-value-type. Sqlite3_handle = None # make sure nobody accesses dangling pointer Print("close result", res)# check res = 0 ![]() Res = libsqlite3.sqlite3_close(sqlite3_handle) Print("pointer value:", sqlite3_handle) # address is set ![]() Print("open result", res) # check res = 0 Res = libsqlite3.sqlite3_open(b"mydb.db", ref(sqlite3_handle)) ![]() Sqlite3_handle = ctypes.c_void_p() # nullptr Libsqlite3 = ctypes.CDLL("libsqlite3.dylib") Any pointer can be replaced by void* as long as it points to a valid memory (i.e. The type-safety is something ensured by the compiler, once we have the machine code, the gloves are off and we can pass anything instead of sqlite3* to the function, but we have to ensure that it would work. Later, we only need the address of this structure to be able to use further functionality, i.e.: int sqlite3_close(sqlite3*) This function will create the structure and give its address to us - no need to know the exact layout of the the structur at all. the second parameter is a pointer to pointer. Sqlite3 **ppDb /* OUT: SQLite db handle */ The sqlite3-API uses an opaque pointer, so in the end there is no need to know its memory layout - one just could use a void-pointer.įor example, opening a sqlite3-database would create such a pointer: int sqlite3_open(Ĭonst char *filename, /* Database filename (UTF-8) */ ![]()
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