I.1  Integrated Database Access

One of the major features of Sheerpower is its ability to perform database operations integrated into the language.

To access the payroll table in a database, you enter the following:

  open table payroll: name '@..\data\payroll'

This opens the payroll table with a reference name of PAYROLL. The table is found in the data folder.
To print the salary field in a payroll table, you would give the name of the table and the name of the field:

  print payroll(salary)

Unlike SQL and many other query languages, Sheerpower is careful to separate data from functions. This makes it impossible for hackers to launch SQL INJECTION ATTACKS against a website that uses Sheerpower on the back end.

In order to access a specific record in a table, it must be current. A successful key lookup causes a record to be current. Within an extract/end extract block, each record becomes current. Within a for each/next block, each record also becomes current.

In general, table records are first collected using extract/end extract and then iterated through using for each/next. This is done as two steps in order for collected records to be optionally sorted.

After any operation that could make a record current, the internal variable _extracted will be zero if no record was found or will reflect the number of records found.

An extract/end extract block can contain:

• exclude nn -- where nn is a logical expression
• include nn -- where nn is a logical expression
• exit extract -- get out of the block with collected records
• cancel extract -- get out of the block without any collected records
• sort by xxx -- where xxx is any arbitrary expression, usually containing a database table reference
• sort descending by xxx -- where xxx is any arbitrary expression as well