Abstract
This section discusses the NdbScanFilter class
and its public members.
Parent class. None
Child classes. None
Description.
NdbScanFilter provides an alternative means of
specifying filters for scan operations.
Prior to MySQL 5.1.14, the comparison methods of this class did
not work with BIT values (see Bug #24503).
Development of this interface continues in MySQL 5.1, and the charcateristics of the NdbScanFilter class are likely to change further in future releases.
Methods. The following table lists the public methods of this class and the purpose or use of each method:
| Method | Purpose / Use |
|---|---|
NdbScanFilter() |
Constructor method |
~NdbScanFilter() |
Destructor method |
begin() |
Begins a compound (set of conditions) |
cmp() |
Compares a column value with an arbitrary value |
end() |
Ends a compound |
eq() |
Tests for equality |
ge() |
Tests for a greater-than-or-equal condition |
getNdbError() |
Provides access to error information |
getNdbOperation() |
Gets the associated NdbOperation
|
gt() |
Tests for a greater-than condition |
isfalse() |
Defines a term in a compound as FALSE
|
isnotnull() |
Tests whether a column value is not NULL
|
isnull() |
Tests whether a column value is NULL
|
istrue() |
Defines a term in a compound as TRUE
|
le() |
Tests for a less-than-or-equal condition |
lt() |
Tests for a less-than condition |
ne() |
Tests for inequality |
For detailed descriptions, signatures, and examples of use for each
of these methods, see Section 2.3.26.2, “NdbScanFilter Methods”.
NdbScanFilter Integer Comparison Methods.
NdbScanFilter provides several convenience
methods which can be used in lieu of the
cmp() method when
the arbitrary value to be compared is an integer:
eq(),
ge(),
gt(),
le(),
lt(), and
ne().
Each of these methods is essentially a wrapper for
cmp() that includes an appropriate value of
BinaryCondition for
that method's condition parameter; for
example, NdbScanFilter::eq() is
defined like this:
int eq(intcolumnId, Uint32value) { return cmp(BinaryCondition::COND_EQ,columnId,&value, 4); }
Types.
The NdbScanFilter class defines two public
types:
BinaryCondition: The type of condition, such as lower bound or upper bound.Group: A logical grouping operator, such asANDorOR.
See Section 2.3.26.1, “NdbScanFilter Types”.
Class diagram.
This diagram shows all the public members of the
NdbScanFilter class:
