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TSTool / Tables

This documentation provides general information about tables.

Introduction

Tables in TSTool are implemented as a generic data object that is based on columns and rows, and can be used to integrate data processing with the following:

  • database tables
  • binary database files
  • Excel worksheets (spreadsheets)
  • delimited and fixed-format files
  • JSON file object arrays
  • time series data (as table)
  • spatial data layer attribute table

Tables have the following design features:

  • Each column must have a consistent data type, which allows commands and formatting to be handled consistently. The table column type can be viewed by right-clicking on the table in the TSTool Results area and selecting the Table properties menu item.
  • Tables each have an identifier, which is used to access the table during processing.
  • Columns are named and rows have number 1+. The table column heading that contain the name are not considered to be a part of the table data.
  • Missing data depend on the data type and are handled internally as:
    • null (generally)
    • empty string (for strings)
    • NaN (for floating point values)
  • Tables can be read from various formats and output to various formats.
  • Table columns have properties including type and, depending on type, width and output precision (for floating point numbers).

Condition Evaluation for Rows

Some commands provide a Condition parameter to limit which rows will be processed by the command. For example, see:

The Condition parameter is restricted to a simple format and comparison and will be enhanced to support more complex syntax over time:

ColumnName operator Value

The ColumnName matches a table column name. The operator is described below. The Value is specified as a constant value consistent with the column type and can be specified with ${Property} that evaluates to a primitive type. The data value from the indicated column is compared to Value. Values can have the following type:

  • integer
  • double (floating point number)
  • string

The operator is one of the following.

  • <
  • <=
  • >
  • >=
  • == (use this to test equality – do not use a single equal sign)
  • !=
  • contains (only for string comparison)
  • !contains (only for string comparison)
  • isempty (only for string comparison, and Value should not be specified)
  • !isempty (only for string comparison, and Value should not be specified)

Additional criteria for strings include:

  • For < and > comparisons, A is less than Z, etc. as per the ASCII table.
  • Comparisons are case-specific. Support for case-independent comparisons may be added in the future.
  • Null string is treated as empty string for isempty and !isempty operators.