The primary use for the _timestamp system variable will be internal to the mSQL

engine. Using this information, the engine may determine if a row has been modified

after a specified point in time (the start of a transaction for example). It may also use

this value to synchronise a remote database for database replication. Although neither

of these functions is currently available, the presence of a row timestamp is the first

step in the implementation.

Example queries may be:

select first_name, _timestamp from emp_details

H   

where first_name like  %fred% 

order by _timestamp

select * from emp_details

where _timestamp 88880123

_seq

The _seq system variable is used to access the current sequence value of the table from

which it is being selected. The current sequence value is returned and the sequence is

update to the next value in the sequence (see the CREATE section of the Language

Specification section from more information on sequences).

An example query using _seq could be

select _seq from staff

H   

_sysdate

The server can provide a central standard for the current time and date. If selected from

any

 table, the _sysdate system variable will return the current time and date on the

server machine using the standard UNIX time format (e.g. seconds since the epoch).

An example query using _sysdate could be

select _sysdate from staff

H   

_user

By selecting the _user system variable from 

any

 table, the server will return the

username of the user who submitted the query.

An example query using _user could be

select _user from staff

H   

Mini SQL 2.0 (Beta) C Programming API

Introduction

Included in the distribution is the mSQL API library, libmsql.a. The API allows

any C program to communicate with the database engine. The API functions are

accessed by including the msql.h header file into your program and by linking

against the mSQL library (using  lmsql as an argument to your C compiler).