NexusDB

 
Declaration

TnxFieldsDescriptor = class(TnxDictionaryItem)

 
Description

The text for this class has been generated automatically. This means that it is not documented.

 
Methods

AddField

This function adds a new instance of a Field Descriptor to the data dictionary and returns the newly created Instance.

CheckRequiredRecordFields

Given a record buffer, checks that all required fields are non-null. Returns true if the record is valid.

CheckValid

This method is called to check the validity of the item. If a descendant needs to validate settings, this method should be overridden and on error raise a an exception.

Clear

This function clears the Data Dictionary.

Create

constructor.

Destroy

destructor.

GetFieldFromName

Return the field number for a given field name, or -1 if not found.

GetFields

Fills a TStrings object with a list of all fields and references to the TnxFieldDescriptor objects.

GetRecordField

Given a record buffer, reads the field data.

GetRecordFieldForFilter

The text for this method has been generated automatically. This means that it is not documented.

GetRecordFieldForFilter

Given a record buffer, returns the pointer to the field data. Be careful because aValue is NOT a copy of the data but a pointer into the actual record buffer. This is a VERY fast method to access the raw field data.

HasAutoIncField

Return True and the index of the first autoinc field in the dictionary.

HasBlobFields

Returns True if the table contains any Blob fields.

HasDefaultFields

This function returns true if the data dictionary has a Field Descriptor with a Default Value Descriptor assigned to it.

HasRecRevField

Return True and the index of the first recrev field in the dictionary.

HasRequiredFields

This function returns true if the Data Dictionary has at least one a Field Descriptor that is required.

HasSameFields

Use this method to verify a dictionary has the same field types, sizes, and ordering as a source dictionary. Returns True if the field information matches otherwise returns False. Note that the fields may have different names. If the record contains any Blob fields, the number of each Blob field is stored in output parameter aBlobFields.

InitRecord

Given a record buffer, initialize it so that all fields are null

InsertFieldAt

This function adds a new instance of a Field Descriptor to the data dictionary and returns the newly created Instance. The field is inserted into the array at position aInx and the rest of the field array indexes are adjusted.

IsEqual

The IsEqual function should return true if the given aDictionaryItem is of the same type and has *exactly* the same settings. Should be overridden by all descendants.

IsRecordFieldNull

Given a record buffer, return True if the field is null.

LoadFromReader

The text for this method has been generated automatically. This means that it is not documented.

MoveField

The text for this method has been generated automatically. This means that it is not documented.

RemoveField

Remove a Field Descriptor from the Data Dictionary.

SaveToWriter

The text for this method has been generated automatically. This means that it is not documented.

SetRecordField

Given a record buffer, write the required field from the buffer pointed to by aValue; if aValue is nil, the field is set to null.

SetRecordFieldNull

Given a record buffer, set the required field to null or non-null. Set the field in the record to binary zeros.

UpdateLogRecLenAlign

The text for this method has been generated automatically. This means that it is not documented.

 
Properties

LogicalRecordLength

The length of the logical record for the data dictionary (ie just the total size of the fields.

RecordLength

The length of the physical record for the data dictionary. Includes trailing byte array to identify null fields.

 
File

 
nxsdDataDictionary