This page is for data modellers and application designers. It explains stream attribute data types.

Overview

All attributes have a data type. When loading data from a source, such as a file or database, PhixFlow applies the data type from the source. If there is no data type specified, PhixFlow applies the default type of string String.

You can change the type of an attribute before the data has been loaded into the streamtable.

Once the stream table contains stream-items ( records), you may be able to change the attribute's data type, depending on the database on which PhixFlow runs. PhixFlow reports an error if you are not permitted to change the data type. In this case you can rollback all record-sets recordsets so that the stream table no longer contains stream itemsrecords; see Rollback Recordsets.

String

Apply a string type to sequences of characters, such as letters, numerals, symbols and punctuation marks. By default string attribute types have a default length of 50. Specify a different string length in Basic Settings → Length.

Bigstring

Apply a bigstring type to text strings over 4000 characters long. Bigstring is a different data type to string. For PhixFlow instances that use an Oracle database, bigstrings:

• cannot be sorted or aggregated
• can only be filtered with the conditions:
  • (not) contains
  • is (not) null
  • (not) starts with
  • (not) ends with.

Bigstring attributes cannot be indexed or set as a 

The PhixFlow administrator can configure set the length of a bigstring using System Configuration → System Tuning → Maximum Bigstring Size.

Integer

Apply an integer type to whole numbers (not fractions or decimals) that can be positive, negative, or zero. By default integers have a precision of 10 digits. Specify a different integer length in the Basic Settings → Precision.

 If you store a number with decimal places as an integer, it will be truncated.

Float

Apply a float type to non-integer numbers with an undefined level of precision.

Decimal

Apply a decimal type to non-integer numbers with a set level of precision.

Decimals have a specific number of:

• significant figures: the total number of digits stored, 
• decimal places: the number of digits after the decimal place.

The maximum number of integer digits is therefore the significant figure minus the decimal places. By default, decimals have 10 significant figures and 2 decimal places, and therefore 8 integer digits.

If the number of integer digits present in a decimal field exceeds the specified format, running analysis will fail and PhixFlow will report an error.

If the number of decimal digits present in a decimal field exceeds the specified format, PhixFlow will round rounds to the required precision. For example, if a data record includes the number 12.3456, but the decimal type can have 4 significant figures and 2 decimal places, PhixFlow records 12.35.

The PhixFlow administrator can configure set the default number of decimal places is set in System Configuration → General Settings → Decimal places.

Dates

Apply a date type to representations of a calendar day. Word formats, such as Tuesday the fourteenth of February are not recognised. However, three letter month abbreviations are recognised, for example: 14 Feb 2019.

The following date formats, have:

• y represents year digits
• M represents month digits or MMM represents three letters
• d represents day digits
• separators can be forward slash / hyphen - or a space.

The default number of date format is set PhixFlow administrator can set the default date format in System Configuration → General Settings → Default Date Format.

If the System Configuration or Number Format option to Suppress Trailing Zeroes is set, PhixFlow will display decimals and floating point numbers without trailing zeroes.

Recognised Date Formats

PhixFlow recognises:

• the international standard format has not separators and is format  yyyyMMdd, for example 20190214. 
  This date has no separators.
• the following variations (examples , in which:
  • y represents year digits
  • M represents month digits or MMM represents three letters
  • d represents day digits

The examples are shown with space separators

. Other recognised separators are:

• forward slash /
• hyphen -
• or a space.

Datetime

Apply a datetime type to representations of a day and a time. It cannot be used to represent a time alone.

Datetimes can have any of the above date formats followed by a space separator and HH:mm:ss. for example MM/dd/yy HH:mm:ss represents a datetime such as 02/14/19 15:35:06.

• H represents hour digits (24 hour)
• m represents minute digits
• s represents second digits
• time separators are colons :

The international datetime uses a full stop/period as a separator between the date and time, yyyyMMdd.HHmmss, for example 20190214.15:35:06.

The default number of date format is set PhixFlow administrator can set the datetime format in System Configuration → General Settings → Default Date/Time Format.

Graphic

Apply a graphic type to fields that contain image files.

True or False Values

Apply the Basic Settings → Type of TrueFalse to fields that can have the values that represent true or false.

• an empty/null field.

Structured Data 

Anchor
structured structured

This data type is only available for attributes in the following actionflow nodes and their connection points:

• calculate Calculate node
• Analysis node
• JSON node
• analysis XML node. 

A Use the structured data value contains type where an attribute contains:

• a list (an array of values)
• values in different formats, such as

• an integer or a string
• values in a format that is not consistent with any other data type.

In an actionflow, a structured data attribute is useful when you need to pass a list of identifiers through to another actionflow node or out of the actionflow, to a screen.

Geometric Data Types

Functions have been created to perform geometric operations on "Well Known Text", geometric representations of points, lines and polygons.

See Geometric Functions for more detail.

File

File is a special data type that is used exclusively with File Display Screen Component and the the table of type File Table. File houses file information in the form of a preview.