About the Structured Query Language (SQL)...
SQL commands are mainly categorised into four categories as:
DDL: Data Definition Language
DQL: Data Query Language
DML: Data Manipulation Language
DCL: Data Control Language
- DDL creates the tables with the required columns and with correct data types (numbers, dates, text strings, etc.)
- DQL reads (select) from one or more rows of one or more tables in the database.
- DML writes a new row (insert) to one or more tables in the database or updates existing fields in one more rows of a table. DML can also delete one or more rows in a table in the database.
- DCL authorizes (grants) the database user to perform DDL, DQL or DML operations or revoke the database user's privileges to perform database operations.
SQL is a common database language used in many Relational Database Management Systems (RDBMS) but it has a lot of dialects.
SQL-92 statements are interpreted by most RDBMS.
Read more about SQL here...
Selecting the right database definition file during installation
n-gen.net CMS offers all database actions required compiled into one .sql file to get you started.
The install[yyyy-MM-dd].sql file contains all the table definitions (DDL) and initial data (DML) to make your n-gen.net CMS immediately operational in a few clicks.
If you are in doubt you should always select the newest install[yyyy-MM-dd].sql file!
Typically the installation files follow these naming conventions:
? install[yyyy-MM-dd].sql => an SQL-file that contains all you need for installing n-gen.net CMS,
i.e. install[2020-06-06].sql
? install_addXXX[yyyy-MM-dd].sql => an SQL-file that contains new tables to be added to the database. This type of .sql files are only required for upgrading an existing installation of n-gen.net CMS.
