_Validation Table

[This is preliminary documentation and subject to change.]

The _Validation table is a system table that contains the column names and the column values for all of the tables in the database. It is used during the database validation process to ensure that all columns are accounted for and have the correct values. This table is not shipped with the installer database.

The _Validation table has the following columns.

Column Type Key Nullable
Table Identifier Y N
Column Identifier Y N
Nullable Text N
MinValue DoubleInteger Y
MaxValue DoubleInteger Y
KeyTable Identifier Y
KeyColumn Integer Y
Category Text Y
Set Text Y
Description Text Y

Columns

Table
Used to identify a particular table. This key and the Column key form the primary key of the _Validation table.
Column
Used to identify a particular column of the table. This key and the Table key form the primary key of the _Validation table.
Nullable
Identifies whether or not the column may contain a Null value.

This column may have one of the following values.
String Meaning
Y Yes, the column may have a Null value.
N No, the column may not have a Null value.
@ The column is a key column for the table, but it may have a Null value.

MinValue
The minimum value allowed. May be the minimum value for an integer or the minimum value for a date or version string.

Non-negative numbers only.

MaxValue
The maximum value allowed. May be the maximum value for an integer or the maximum value for a date or version string.

Non-negative numbers only.

KeyTable
For an external key column, name of the external table to which the data must link. May be a list of tables separated by semicolons.
KeyColumn
For an external key column, column number in the table specified by KeyTable to which the data must link.

Range 1-32.

Category
A category of string or data that defines the type of data contained in the column.

This string must be one of the types described in Column Data Types. The validation table is used to ensure that the table entries are the correct types as specified by the Category column.

Set
The set of possible values allowed, separated by semicolons. Most often used when dealing with enums.
Description
The description of the data that is stored in the column.