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4.19.2.16 NdbTransaction::insertTuple() »
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4.19.2.15. NdbTransaction::readTuple()

Description.  This method reads a tuple using NdbRecord objects.

Signature.  

NdbOperation* readTuple
    (
      const NdbRecord* key_rec, 
      const char* key_row,
      const NdbRecord* result_rec, 
      char* result_row,
      NdbOperation::LockMode lock_mode = NdbOperation::LM_Read,
      const unsigned char* result_mask = 0
    )

Parameters.  This method takes the following parameters:

  • key_rec is a pointer to an NdbRecord for either a table or an index. If on a table, then the operation uses a primary key; if on an index, then the operation uses a unique key. In either case, the key_rec must include all columns of the key.

  • The key_row passed to this method defines the primary or unique key of the affected tuple, and must remain valid until execute() is called.

  • result_rec is a pointer to an NdbRecord used to hold the result

  • result_row defines a buffer for the result data.

  • lock_mode specifies the lock mode in effect for the operation. See Section 4.15.1.3, “The NdbOperation::LockMode Type”, for permitted values and other information.

  • result_mask defines a subset of attributes to read. Only if mask[attrId >> 3] & (1<<(attrId & 7)) is set is the column affected. The mask is copied, and so need not remain valid after the method call returns.

Return Value.  The NdbOperation representing this operation (can be used to check for errors).