Database/DKDB SQL format
From Lanius CMS Wiki
Lanius CMS uses internally a special format for its SQL data; this is the general specification of such format:
- a DKDB SQL file must be UTF-8 encoded without BOM header;
- either a PHP, SQL or GZ extension is allowed;
- the first line of the (eventually uncompressed) file must be like the following
/* @DKDB 0.4 @GID 5 <?php if (@$my->gid< 5)die; ?> */
- comments start with /* and end with */, even multi-line (as the SQL standard specifies)
- each delimited string (through the SQL standard single quote character ') can contain any binary data
- there are no recognized escape characters, the only recognized escape sequence is that of single quote characters ' which delimits SQL strings; two subsequent single quote characters (hexadecimal \x27\x27) always evaluate to a single quote character
The SQL data is re-encoded (and correctly escaped) for the target database system by Lanius CMS itself; following the above DKDB SQL standard format you will allow maximum portability between different database systems.
Note: the DKDB SQL format is used natively by Gladius DB; strings will be re-encoded for each database system upon import
SQL constraints
In order to avoid incompatibilities it is suggested to use a plain simple syntax as most compliant to SQL92 as possible, but taking in account the following:
- do not use display lengths (like in int(10))
- use INTEGER instead of INT and VARCHAR for string types, possibly upper case
- use the TEXT field for unlimited length strings
- possibly use FLOAT for floating-point data types
- use AUTO_INCREMENT for automatically incremented columns (it will be automatically translated into SERIAL for PostgreSQL)
- do not use JOINs and GROUP BY in SQL queries
