Prev

Next

Index-> contents reference index search external

Up-> dismod_at database

@(@\newcommand{\B}[1]{ {\bf #1} } \newcommand{\R}[1]{ {\rm #1} } \newcommand{\W}[1]{ \; #1 \; }@)@This is dismod_at-20221105 documentation: Here is a link to its current documentation . The Dismod_at Database Tables
Comment Columns and Tables
Primary Key
Name Column
Foreign Key
     parent
Null
     Bounds
     Integer
     Text can be Null, not Empty
     Real Can be Null, not Nan
Type Names
Contents

Comment Columns and Tables
Any table (in this database) may have any number of columns with names that begin with the two characters c_. These are comment columns and are ignored by dismod_at. In addition, tables with a names beginning with c_ are also considered comments and are ignored by dismod_at.

Primary Key
If table_name is a table (in this database), its first column has name table_name_id that is the primary key for the table. The values in this column are integer, start at zero and increment by one for each row in the table.

Name Column
Suppose that table_name is a table (in this database), and the column table_name_name exists. In this case, the values in this column are text must be unique; i.e., the names can act as substitutes for the primary key. The names are intended to be easier for a human to remember than the ids.

Foreign Key
If this is the name of a table its primary key is the column this_id . If this primary key is used in another table it is called a foreign key (in the other table). The name of the column in the other table will be this_id or it will end with _this_id . A value in the foreign key column must also appear in the corresponding primary key column, or it must be null.

parent
Note that the column parent is a primary key value for the node table ; i.e, node_id. Note that this column is not named node_id nor does it end in _node_id . This is not an exception because the parent column is itself in the node table and hence this is not a foreign key.

Null
It is an error for a value to be null unless the documentation for the corresponding column specifies a meaning for this case. Lower and upper bounds are an exception to this rule (see below).

Bounds
If a lower (upper) bound is null, it is interpreted as minus (plus) infinity.

Integer
The minimum integer (negative integer with the largest absolute value) is used to represent a null integer value in a table. An error message will be generated if the minimum integer appears in a table that is read by dismod_at.

Text can be Null, not Empty
The empty string is used to represent a null text value in a table. An error message will be generated if the empty string appears in a text field that is read by dismod_at.

Real Can be Null, not Nan
If a real value is null, it is represented as nan. An error message will be generated if the value nan appears in a table that is read by dismod_at.

Type Names
The types in this database are integer, real and text. The type names INTEGER, REAL, and TEXT can also be used.

Contents

input	Tables That Are Only Used as Inputs
data_flow	The Dismod_at Data Flow

---

Input File: omh/table/database.omh