This system was demonstrated using InfoMaker. There was an immediately apparent difference between this and the previous forms. Instead of using data in a simple value, single words or numbers, data was seen as strings, forming blocks of text, dates and images.

For text blocks the system made use of scrollable text boxes. This allowed for more text than the given space allowed.

Images could be represented by the image itself or a specified path to the image file itself. Is an image stored in this way a part of a database? I'll guess it is!

The Design view enables the user to manipulate the appearance of the form by selecting and then altering/moving the objects represented on the form.

The descriptions within the Design view use words separated by underscores '_'. The first word in the description indicate the use of a table of that name. e.g.

• Bird_common_name - This is located in a table named Bird?
• The remainder of the term - common_name locates to a column in the bird table.
• This column name is transformed for use as the label - Common Name.

Dates can be entered in any valid format, but will be transformed into another format for viewing. This is dependent on how it is stored and subsequently displayed.

I am having a problem here! The user sees data as one table - the source of data in the database is two tables! As the text says how do we transform two database tables into one table for the form? More later, no doubt!

There followed a brief description and run through of creating a new form. This was accompanied by a glimpse of SQL (Structured Query Language). An SQL statement specifies the data that is to be retrieved from a relational database.

Data Manipulation - updating or retrieving data. What is an Integrity constraint violation? It prevents changing of data to something inappropriate to the database at the time e.g. The data entered does not match any known value in the database. How's that done? The values existing in the database will not reflect inappropriate data entry - hence - Integrity constraint violation i.e. a semantic constraint - data without meaning!

Columns within tables have data types e.g. varchar (character varying) and date (self explanatory I hope!).

A derived table is a viewed table or view. A table of stored data is a base table (from database?).

Comments, suggestions, ideas to
Stuart Banner