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NdbIndexOperation,NdbScanOperation

NdbOperation represents a“generic” data operation. Its subclasses represent more specific types of operations. SeeNdbOperation::Type for a listing of operation types and their correspondingNdbOperation subclasses.

The following table lists the public methods of this class and the purpose or use of each method:

This class has no public constructor. To create an instance ofNdbOperation, you must useNdbTransaction::getNdbOperation().

TheNdbOperation class defines three public types, shown in the following table:

This type is used to determine whether failed operations should force a transaction to be aborted. It is used as an argument to theexecute() method—seeNdbTransaction::execute(), for more information.

Possible values are shown, along with descriptions, in the following table:

Add contents of two registers; store result in a third register.

int add_reg    (      Uint32RegSource1,       Uint32RegSource2,       Uint32RegDest    )

0 on success, otherwise -1.

Branch to a label in an interpreted program if the specified column isNULL.

int branch_col_eq_null    (      Uint32ColId,       Uint32Label    )

0 on success, otherwise -1.

Branch to a label in an interpreted program if the specified column is notNULL.

int branch_col_ne_null    (      Uint32ColId,       Uint32Label    )

none

Branch to a label in an interpreted program if a given value is equal to the value of the specified column.

int branch_col_eq    (      Uint32ColId,       const void*val,       Uint32len,      bool,      Uint32Label    )

0 on success, -1 otherwise.

Branch to a label in an interpreted program if a given value is not equal to the value of the specified column.

int branch_col_ne    (      Uint32ColId,       const void*val,       Uint32len,      bool,      Uint32Label    )

0 on success, else -1.

Branch to a label in an interpreted program if a given value is less than a column value.

int branch_col_lt    (      Uint32ColId,       const void*val,       Uint32len,      bool,      Uint32Label    )

0 on success, otherwise -1.

Branch to a label in an interpreted program if a given value is less than or equal to a column value.

int branch_col_le    (      Uint32ColId,       const void*val,       Uint32len,      bool,      Uint32Label    )

On success, 0; otherwise, -1.

Branch to a label in an interpreted program if a given value is greater than a column value.

int branch_col_gt    (      Uint32ColId,       const void*val,       Uint32len,      bool,      Uint32Label    )

0 on success, -1 otherwise.

Branch to a label in an interpreted program if a given value is greater than or equal to a column value.

int branch_col_ge    (      Uint32ColId,       const void*val,       Uint32len,      bool,      Uint32Label    )

0 if successful, else -1.

Branch if the column value matches a wildcard pattern. This method andbranch_col_notlike() each support the wildcards used by the MySQLLIKE operator:% for any string of 0 or more characters, and_ for any single character.

The column's type must be one ofCHAR,VARCHAR,BINARY, orVARBINARY.

int branch_col_like    (      Uint32ColId,       const void*val,       Uint32len,      bool,      Uint32Label    )

0 on success, otherwise -1.

Branch if the column value does not match the given wildcard pattern. This method andbranch_col_like() each support the same wildcards% (0 or more characters) and_ (any one character) as the MySQLLIKE operator.

The column's type must be one ofCHAR,VARCHAR,BINARY, orVARBINARY.

int branch_col_notlike    (      Uint32ColId,       const void*val,       Uint32len,      bool,      Uint32Label    )

0 on success, -1 otherwise.

Branch if the value of a column in a logical bitwiseAND with a bitmask is equal to the bitmask.

See alsoBitwise logical comparisons.

int branch_col_and_mask_eq_mask    (      Uint32ColId,       const void*mask,       Uint32len,      bool,      Uint32Label    )

0 on success, -1 otherwise.

Branch if the value of a column in a logical bitwiseAND with a bitmask is not equal to the bitmask.

See alsoBitwise logical comparisons.

int branch_col_and_mask_ne_mask    (      Uint32ColId,       const void*mask,       Uint32len,      bool,      Uint32Label    )

On success 0, else -1.

Branch if the value of a column in a logical bitwiseAND with a bitmask is equal to 0.

See alsoBitwise logical comparisons.

int branch_col_and_mask_eq_zero    (      Uint32ColId,       const void*mask,       Uint32len,      bool,      Uint32Label    )

0 on success, -1 otherwise.

Branch if the value of a column in a logical bitwiseAND with a bitmask is not equal to 0.

See alsoBitwise logical comparisons.

int branch_col_and_mask_ne_zero    (      Uint32ColId,       const void*mask,       Uint32len,      bool,      Uint32Label    )

Returns 0 on success, -1 otherwise.

Define a search condition in an interpreted program. Compares the right-hand register value with the left; branch to a label if the RH value is greater than or equal to the LH value.

int branch_ge    (      Uint32RegLvalue,       Uint32RegRvalue,       Uint32Label    )

0 on success, -1 otherwise.

Define a search condition in an interpreted program. Compares the right-hand register value with the left; branch to a label if the RH value is greater than the LH value.

int branch_gt    (      Uint32RegLvalue,       Uint32RegRvalue,       Uint32Label    )

0 on success, -1 otherwise.

Define a search condition in an interpreted program. Compares the right-hand register value with the left; branch to a label if the RH value is less than the LH value.

int branch_le    (      Uint32RegLvalue,       Uint32RegRvalue,       Uint32Label    )

0 on success, -1 otherwise.

Define a search condition in an interpreted program. Compares the right-hand register value with the left; branch to a label if the RH value is less than or equal to the LH value.

int branch_lt    (      Uint32RegLvalue,       Uint32RegRvalue,       Uint32Label    )

0 on success, -1 otherwise.

Branch to a label in an interpreted program when two register values are equal.

int branch_eq    (      Uint32RegLvalue,       Uint32RegRvalue,       Uint32Label    )

0 on success, -1 otherwise.

Branch to a label in an interpreted program when two register values are not equal.

int branch_eq    (      Uint32RegLvalue,       Uint32RegRvalue,       Uint32Label    )

0 on success, otherwise -1.

Branch to a label in an interpeted program if a register value is notNULL.

int branch_ne_null    (      Uint32RegLvalue,       Uint32Label    )

On success, returns 0; otherwise, returns -1.

Branch to a label in an interpeted program if a register value isNULL.

int branch_ne_null    (      Uint32RegLvalue,       Uint32Label    )

On success, 0; otherwise, -1.

Jump to a label in an interpeted progam.

int branch_label    (      Uint32Label    )

0 if successful; otherwise, -1.

Call a subroutine in an interpeted program.

int call_sub    (      Uint32Subroutine    )

If successful, returns 0; otherwise, returns -1.

Define a jump label in an interpreted operation. Labels are numbered automatically starting with 0.

int def_label    (      intlabelNumber    )

labelNumber on success, -1 otherwise.

Define a subroutine in an interpreted program.

int def_subroutine    (      intSubroutineNumber    )

0 on success, -1 otherwise.

This method defines theNdbOperation as aDELETE operation. When theNdbTransaction::execute() method is invoked, the operation deletes a tuple from the table.

virtual int deleteTuple    (      void    )

None.

Returns0 on success,-1 on failure.

This method defines a search condition with an equality. The condition is true if the attribute has the given value. To set search conditions on multiple attributes, use several calls toequal(); in such cases all of them must be satisfied for the tuple to be selected.

If the attribute is of a fixed size, its value must include all bytes. In particular aChar value must be native-space padded. If the attribute is of variable size, its value must start with 1 or 2 little-endian length bytes (2 if its type isLong*).

When usinginsertTuple(), you may also define the search key withsetValue(). SeeNdbOperation::setValue().

There are 10 versions ofequal(), each having slightly different parameters. All of these are shown here:

int  equal    (      const char*name,      const char*value    )int  equal    (      const char*name,      Int32value    )int  equal    (      const char*name,      Uint32value    )int  equal    (      const char*name,      Int64value    )int  equal    (      const char*name,      Uint64value    )int  equal    (      Uint32id,      const char*value    )int  equal    (      Uint32id,      Int32value    )int  equal    (      Uint32id,      Uint32value    )int  equal    (      Uint32id,      Int64value    )int  equal    (      Uint32id,      Uint64value    )

This method requires two parameters:

Returns-1 in the event of an error.

This method is used in place ofgetValue() orsetValue() for blob attributes. It creates a blob handle (NdbBlob object). A second call with the same argument returns the previously created handle. The handle is linked to the operation and is maintained automatically.

This method has two forms, depending on whether it is called with the name or the ID of the blob attribute:

virtual NdbBlob* getBlobHandle    (      const char* name    )

or

virtual NdbBlob* getBlobHandle    (      Uint32 id    )

This method takes a single parameter, which can be either one of the following:

Regardless of parameter type used, this method return a pointer to an instance ofNdbBlob.

Returns a pointer to the current operation's lock handle. When used withNdbRecord, the lock handle must first be requested with theOO_LOCKHANDLE operation option. For other operations, this method can be used alone. In any case, theNdbLockHandle object returned by this method cannot be used until the operation has been executed.

const NdbLockHandle* getLockHandle    (      void    ) const

or

const NdbLockHandle* getLockHandle    (      void    )

None.

Pointer to anNdbLockHandle that can be used by theNdbTransaction methodsunlock() andreleaseLockHandle().

This method gets the operation's lock mode.

LockMode getLockMode    (      void    ) const

None.

ALockMode value. SeeNdbOperation::LockMode.

This method gets the most recent error (anNdbError object).

const NdbError& getNdbError    (      void    ) const

None.

AnNdbError object.

This method retrieves the method number in which the latest error occurred.

int getNdbErrorLine    (      void    ) const

None.

The method number (an integer).

This method is used to retrieve the table object associated with the operation.

const NdbDictionary::Table* getTable    (      void    ) const

None.

A pointer to an instance ofTable.

This method retrieves the name of the table used for the operation.

const char* getTableName    (      void    ) const

None.

The name of the table.

Gets theNdbTransaction object for this operation.

virtual NdbTransaction* getNdbTransaction    (      void    ) const

None.

A pointer to anNdbTransaction object.

This method is used to retrieve the access type for this operation.

Type getType    (      void    ) const

None.

AType value.

This method prepares for the retrieval of an attribute value. The NDB API allocates memory for anNdbRecAttr object that is later used to obtain the attribute value. This can be done by using one of the manyNdbRecAttr accessor methods, the exact method to be used depending on the attribute's data type. (This includes the genericNdbRecAttr::aRef() method, which retrieves the data aschar*, regardless of its actual type. You should be aware that this is not type-safe, and requires an explicit cast from the user.)

This method doesnot fetch the attribute value from the database; theNdbRecAttr object returned by this method is not readable or printable before callingNdbTransaction::execute().

If a specific attribute has not changed, the correspondingNdbRecAttr has the stateUNDEFINED. This can be checked by usingNdbRecAttr::isNULL(), which in such cases returns-1.

SeeNdbTransaction::execute(), andNdbRecAttr::isNULL().

There are three versions of this method, each having different parameters:

NdbRecAttr* getValue    (      const char*name,      char*value = 0    )NdbRecAttr* getValue    (      Uint32id,      char*value = 0    )NdbRecAttr* getValue    (      const NdbDictionary::Column*col,      char*value = 0    )

All three forms of this method have two parameters, the second parameter being optional (defaults to0). They differ only with regard to the type of the first parameter, which can be any one of the following:

In all three cases, the second parameter is a character buffer in which a non-NULL attribute value is returned. In the event that the attribute isNULL, is it stored only in theNdbRecAttr object returned by this method.

If novalue is specified in thegetValue() method call, or if 0 is passed as the value, then theNdbRecAttr object provides memory management for storing the received data. If the maximum size of the received data is above a small fixed size,malloc() is used to store it: For small sizes, a small, fixed internal buffer (32 bytes in extent) is provided. This storage is managed by theNdbRecAttr instance; it is freed when the operation is released, such as at transaction close time; any data written here that you wish to preserve should be copied elsewhere before this freeing of memory takes place.

If you pass a non-zero pointer forvalue, then it is assumed that this points to an portion of memory which is large enough to hold the maximum value of the column; any returned data is written to that location. The pointer should be at least 32-bit aligned.

Index columns cannot be used in place of table columns with this method. In cases where a table column is not available, you can use the attribute name, obtained withgetName(), for this purpose instead.

A pointer to anNdbRecAttr object to hold the value of the attribute, or aNULL pointer, indicating an error.

NdbOperation

This structure is used to specify an extra value to obtain as part of anNdbRecord operation.

The elements making up this structure are shown in the following table:

Blob reads cannot be specified usingGetValueSpec.

Interpreted program instruction which adds a value to an attribute. The attribute can be specified by name or by ID. Thus, there are four versions of of this method having slightly different parameters, as shown underSignature.

This instruction uses registers 6 and 7, and overwrites these registers in the course of its operation.

For scans andNdbRecord operations, use theNdbInterpretedCode interface instead.

int incValue    (      const char*anAttrName,       Uint32aValue    )

int incValue    (      const char*anAttrName,       Uint64aValue    )

int incValue    (      Uint32anAttrId,       Uint32aValue    )

int incValue    (      Uint32anAttrId,       Uint64aValue    )

0 on success, -1 otherwise.

This method defines theNdbOperation to be anINSERT operation. When theNdbTransaction::execute() method is called, this operation adds a new tuple to the table.

virtual int insertTuple    (      void    )

None.

Returns0 on success,-1 on failure.

Terminate the entire transaction.

int interpret_exit_last_row    (      void    )

none

Returns 0 on success; otherwise, returns -1.

Exit interpreted program with statusNOT OK and an optional error code (seeSection 2.4.2, “NDB Error Codes: by Type”).

int interpret_exit_nok    (      Uint32ErrorCode    )int interpret_exit_nok    (      void    )

0 on success, -1 otherwise.

Exit interpreted program with statusOK.

int interpret_exit_ok    (      void    )

none

0 on success, -1 otherwise.

Delete a tuple using an interpreted program.

virtual int interpretedDeleteTuple    (      void    )

None.

0 on success, -1 otherwise.

Update a tuple using an interpreted program.

virtualint interpretedUpdateTuple    (      void    )

None.

0 on success, -1 otherwise.

Write a tuple using an interpreted program.

virtualint interpretedWriteTuple    (      void    )

None.

0 on success, -1 otherwise.

Load a 32-bit constant value into a register.

int load_const_u32    (      Uint32RegDest,       Uint32Constant    )

0 on success, -1 otherwise.

Load a 64-bit constant value into a register.

int load_const_u64    (      Uint64RegDest,       Uint64Constant    )

0 on success, otherwise -1.

LoadNULL into a register.

int load_const_null    (      Uint32RegDest    )

0 on success, -1 otherwise.

This type describes the lock mode used when performing a read operation.

Possible values for this type are shown, along with descriptions, in the following table:

There is also support for dirty reads (LM_Dirty), but this is normally for internal purposes only, and should not be used for applications deployed in a production setting.

NdbOperation

These options are passed to theNdbRecord-based primary key and scan takeover operation methods defined in theNdbTransaction andNdbScanOperation classes.

MostNdbTransaction::*Tuple() methods (seeSection 2.3.25, “The NdbTransaction Class”) take a supplementarysizeOfOptions parameter. This is optional, and is intended to permit the interface implementation to remain backward compatible with older un-recompiled clients that may pass an older (smaller) version of theOperationOptions structure. This effect is achieved by passingsizeof(OperationOptions) into this parameter.

Each option type is marked as present by setting the corresponding bit inoptionsPresent. (Only the option types marked inoptionsPresent need have sensible data.) All data is copied out of theOperationOptions structure (and any subtended structures) at operation definition time. If no options are required, thenNULL may be passed instead.

The elements making up this structure are shown in the following table:

Read an attribute identified by name or ID into a register.

int read_attr    (      const char*anAttrName,       Uint32RegDest    )int read_attr    (      Uint32anAttrId,       Uint32RegDest    )

On success, 0; otheriwse, -1.

This method defines theNdbOperation as aREAD operation. When theNdbTransaction::execute() method is invoked, the operation reads a tuple.

virtual int readTuple    (      LockModemode    )

mode specifies the locking mode used by the read operation. SeeNdbOperation::LockMode, for possible values.

Returns0 on success,-1 on failure.

Return from an interpreted program subroutine.

int ret_sub    (      void    )

none.

0 on success, -1 otherwise.

This method defines an attribute to be set or updated.

There are a number ofNdbOperation::setValue() methods that take a certain type as input (pass by value rather than passing a pointer). It is the responsibility of the application programmer to use the correct types.

The NDB API does check that the application sends a correct length to the interface as given in the length parameter. Achar* value can contain any data type or any type of array. If the length is not provided, or if it is set to zero, then the API assumes that the pointer is correct, and does not check it.

To set aNULL value, use the following construct:

setValue("ATTR_NAME", (char*)NULL);

When you useinsertTuple(), the NDB API automatically detects that it is supposed to useequal() instead.

In addition, it is not necessary when usinginsertTuple() to usesetValue() on key attributes before other attributes.

There are 14 versions ofNdbOperation::setValue(), each with slightly different parameters, as listed here:

int setValue    (      const char*name,      const char*value)int setValue    (      const char*name,      Int32value    )int setValue    (      const char*name,      Uint32value    )int setValue    (      const char*name,      Int64value    )int setValue    (      const char*name,      Uint64value    )int setValue    (      const char*name,      floatvalue    )int setValue    (      const char*name,      doublevalue    )int setValue    (      Uint32id,      const char*value    )int setValue    (      Uint32id,      Int32value    )int setValue    (      Uint32id,      Uint32value    )int setValue    (      Uint32id,      Int64value    )int setValue    (      Uint32id,      Uint64value    )int setValue    (      Uint32id,      floatvalue    )int setValue    (      Uint32id,      doublevalue    )

This method requires the following two parameters:

Returns-1 in the event of failure.

NdbOperation

This structure is used to specify an extra value to set as part of anNdbRecord operation.

The elements making up this structure are shown in the following table:

Store difference of two register values in a third register.

int sub_reg    (      Uint32RegSource1,       Uint32RegSource2,       Uint32RegDest    )

0 on success, otherwise -1.

Interpreted program instruction which subtracts a value from an attribute in an interpreted operation. The attribute can be specified by name or by ID. Thus, there are four versions of of this method having slightly different parameters, as shown underSignature.

As withincValue(), this instruction uses registers 6 and 7, and overwrites these registers in the course of its operation.

For scans andNdbRecord operations, use theNdbInterpretedCode interface instead.

int subValue    (      const char*anAttrName,       Uint32aValue    )

int subValue    (      const char*anAttrName,       Uint64aValue    )

int subValue    (      Uint32anAttrId,       Uint32aValue    )

int subValue    (      Uint32anAttrId,       Uint64aValue    )

0 on success, -1 otherwise.

Type is used to describe the operation access type. Each access type is supported byNdbOperation or one of its subclasses, as shown in the following table:

Possible values are shown, along with descriptions, in the following table:

This method defines theNdbOperation as anUPDATE operation. When theNdbTransaction::execute() method is invoked, the operation updates a tuple found in the table.

virtual int updateTuple    (      void    )

None.

Returns0 on success,-1 on failure.

Write an attribute value from a register. The attribute to be written can be specified by name or ID.

int write_attr    (      const char*anAttrName,       Uint32RegSource    )int write_attr    (      Uint32anAttrId,       Uint32RegSource    )

Returns 0 on success; otherwise, returns -1.

This method defines theNdbOperation as aWRITE operation. When theNdbTransaction::execute() method is invoked, the operation writes a tuple to the table. If the tuple already exists, it is updated; otherwise an insert takes place.

virtual int writeTuple    (      void    )

None.

Returns0 on success,-1 on failure.