wiredtiger.Cursor Class Reference

Python wrapper around C WT_CURSOR. More...

Inherits object.

Public Member Functions
def	__init__
def	next
	next(self) -> int
def	prev
	prev(self) -> int
def	reset
	reset(self) -> int
def	search
	search(self) -> int
def	insert
	insert(self) -> int
def	update
	update(self) -> int
def	remove
	remove(self) -> int
def	close
	close(self, config) -> int
def	compare
	compare(self, other) -> int
def	search_near
	search_near(self) -> int
def	get_key
	get_key(self) -> object
def	get_keys
	get_keys(self) -> (object, ...)
def	get_value
	get_value(self) -> object
def	get_values
	get_values(self) -> (object, ...)
def	set_key
	set_key(self) -> None
def	set_value
	set_value(self) -> None
def	__iter__
	Cursor objects support iteration, equivalent to calling WT_CURSOR::next until it returns WT_NOTFOUND.
def	__getitem__
	Python convenience for searching.

Public Attributes
	this

Static Public Attributes
tuple	thisown
tuple	session
tuple	uri

Detailed Description

Python wrapper around C WT_CURSOR.

Member Function Documentation

def wiredtiger.Cursor.__iter__

(

self

)

Cursor objects support iteration, equivalent to calling WT_CURSOR::next until it returns WT_NOTFOUND.

def wiredtiger.Cursor.close	(		self,
			args
	)

close(self, config) -> int

Close the cursor. This releases the resources associated with the cursor handle. Cursors are closed implicitly by ending the enclosing connection or closing the session in which they were opened.

        ret = cursor->close(cursor);

Parameters

cursor

the cursor handle

Returns

zero on success and a non-zero error code on failure. See Error Returns for details.

def wiredtiger.Cursor.get_key

(

self

)

get_key(self) -> object

Get the key for the current record.

        const char *key;        /* Get the cursor's string key. */
        ret = cursor->get_key(cursor, &key);

        uint64_t recno;         /* Get the cursor's record number key. */
        ret = cursor->get_key(cursor, &recno);

Parameters

cursor	the cursor handle
...	pointers to hold key fields corresponding to WT_CURSOR::key_format.

Returns

zero on success and a non-zero error code on failure. See Error Returns for details.

Returns only the first column.

def wiredtiger.Cursor.get_keys

(

self

)

get_keys(self) -> (object, ...)

Get the key for the current record.

        const char *key;        /* Get the cursor's string key. */
        ret = cursor->get_key(cursor, &key);

        uint64_t recno;         /* Get the cursor's record number key. */
        ret = cursor->get_key(cursor, &recno);

Parameters

cursor	the cursor handle
...	pointers to hold key fields corresponding to WT_CURSOR::key_format.

Returns

zero on success and a non-zero error code on failure. See Error Returns for details.

def wiredtiger.Cursor.get_value

(

self

)

get_value(self) -> object

Get the value for the current record.

        const char *value;      /* Get the cursor's string value. */
        ret = cursor->get_value(cursor, &value);

        WT_ITEM value;          /* Get the cursor's raw value. */
        ret = cursor->get_value(cursor, &value);

Parameters

cursor	the cursor handle
...	pointers to hold value fields corresponding to WT_CURSOR::value_format.

Returns

zero on success and a non-zero error code on failure. See Error Returns for details.

Returns only the first column.

def wiredtiger.Cursor.get_values

(

self

)

get_values(self) -> (object, ...)

Get the value for the current record.

        const char *value;      /* Get the cursor's string value. */
        ret = cursor->get_value(cursor, &value);

        WT_ITEM value;          /* Get the cursor's raw value. */
        ret = cursor->get_value(cursor, &value);

Parameters

cursor	the cursor handle
...	pointers to hold value fields corresponding to WT_CURSOR::value_format.

Returns

zero on success and a non-zero error code on failure. See Error Returns for details.

def wiredtiger.Cursor.insert	(		self,
			args
	)

insert(self) -> int

Insert a record, and optionally overwrite an existing record. If the cursor was not configured with "append" or "overwrite", both the key and value must be set and the record must not already exist; the record will be inserted.If the cursor was configured with "overwrite", both the key and value must be set; if the record already exists, the key's value will be updated, otherwise, the record will be inserted.If a cursor with record number keys was configured with "append", the value must be set; a new record will be appended and the record number set as the cursor key value.Inserting a new record after the current maximum record in a fixed-length bit field column-store (that is, a store with an 'r' type key and 't' type value) implicitly creates the missing records as records with a value of 0.

        /* Insert a new record. */
        const char *key = "some key", *value = "some value";
        cursor->set_key(cursor, key);
        cursor->set_value(cursor, value);
        ret = cursor->insert(cursor);

        /* Insert a new record or overwrite an existing record. */
        ret = session->open_cursor(
            session, "table:mytable", NULL, "overwrite", &cursor);
        cursor->set_key(cursor, key);
        cursor->set_value(cursor, value);
        ret = cursor->insert(cursor);

        /* Insert a new record and assign a record number. */
        uint64_t recno;
        const char *value = "some value";
        ret = session->open_cursor(
            session, "table:mytable", NULL, "append", &cursor);
        cursor->set_value(cursor, value);
        ret = cursor->insert(cursor);
        if (ret == 0)
                ret = cursor->get_key(cursor, &recno);

Parameters

cursor

the cursor handle

Returns

zero on success and a non-zero error code on failure. See Error Returns for details.

def wiredtiger.Cursor.next	(		self,
			args
	)

next(self) -> int

Return the next record.

        ret = cursor->next(cursor);

Parameters

cursor

the cursor handle

Returns

zero on success and a non-zero error code on failure. See Error Returns for details.

def wiredtiger.Cursor.prev	(		self,
			args
	)

prev(self) -> int

Return the previous record.

        ret = cursor->prev(cursor);

Parameters

cursor

the cursor handle

Returns

zero on success and a non-zero error code on failure. See Error Returns for details.

def wiredtiger.Cursor.remove	(		self,
			args
	)

remove(self) -> int

Remove a record. The key must be set, and the key's record will be removed.Removing a record in a fixed-length bit field column-store (that is, a store with an 'r' type key and 't' type value) is identical to setting the record's value to 0.

        const char *key = "some key";
        cursor->set_key(cursor, key);
        ret = cursor->remove(cursor);

Parameters

cursor

the cursor handle

Returns

zero on success and a non-zero error code on failure. See Error Returns for details. In particular, if no record with the specified key exists, WT_NOTFOUND is returned.

def wiredtiger.Cursor.reset	(		self,
			args
	)

reset(self) -> int

Reset the position of the cursor. Any resources held by the cursor are released, and the cursor's key and position are no longer valid. A subsequent iteration with WT_CURSOR::next will move to the first record, or with WT_CURSOR::prev will move to the last record.

        ret = cursor->reset(cursor);

Parameters

cursor

the cursor handle

Returns

zero on success and a non-zero error code on failure. See Error Returns for details.

def wiredtiger.Cursor.search	(		self,
			args
	)

search(self) -> int

Move to the record matching the key. The key must first be set.

        const char *key = "some key";
        cursor->set_key(cursor, key);
        ret = cursor->search(cursor);

Parameters

cursor

the cursor handle

Returns

zero on success and a non-zero error code on failure. See Error Returns for details.

def wiredtiger.Cursor.set_key	(		self,
			args
	)

set_key(self) -> None

Set the key for the next operation.

                                /* Set the cursor's string key. */
        const char *key = "another key";
        cursor->set_key(cursor, key);

        uint64_t recno = 37;    /* Set the cursor's record number key. */
        cursor->set_key(cursor, recno);

Parameters

cursor	the cursor handle
...	key fields corresponding to WT_CURSOR::key_format.

If an error occurs during this operation, a flag will be set in the cursor, and the next operation to access the key will fail. This simplifies error handling in applications.

def wiredtiger.Cursor.set_value	(		self,
			args
	)

set_value(self) -> None

Set the value for the next operation.

                                /* Set the cursor's string value. */
        const char *value = "another value";
        cursor->set_value(cursor, value);

        WT_ITEM value;          /* Set the cursor's raw value. */
        value.data = "another value";
        value.size = strlen("another value");
        cursor->set_value(cursor, &value);

Parameters

cursor	the cursor handle
...	value fields corresponding to WT_CURSOR::value_format.

If an error occurs during this operation, a flag will be set in the cursor, and the next operation to access the value will fail. This simplifies error handling in applications.

def wiredtiger.Cursor.update	(		self,
			args
	)

update(self) -> int

Update a record. Both key and value must be set, the key must exist, and the value of the key's record will be updated.

        const char *key = "some key", *value = "some value";
        cursor->set_key(cursor, key);
        cursor->set_value(cursor, value);
        ret = cursor->update(cursor);

Parameters

cursor

the cursor handle

Returns

zero on success and a non-zero error code on failure. See Error Returns for details. In particular, if no record with the specified key exists, WT_NOTFOUND is returned.