Developer-Guide/datastorage/database/queries.md

Queries

Database

The database query builder provides a uniform way to write default database queries for the following databases:

• MySQL
• PostgreSQL
• SQLite
• MicrosoftSQL
• OracleSQL

Query Builder

The query builder is used for regular CRUD operations on the database.

Prefix

Projects often use a prefix for all of the tables. For this project the default prefix is oms_.

$query = new Builder();
$query->prefix('oms_');

Select, Insert, Update, Delete

Both select and insert expect the column names as parameter. The where, from and into clause can be necessary depending on the type of operation like a normal sql query.

$query->prefix(...)->select('columnA', 'columnB')->from('table')->where(...);
$query->prefix(...)->insert('columnA', 'columnB')->values('a', 'b')->into('table');

The update expects the table name which should be updated and then the set function to define the columns and new values.

$query->prefix(...)->update('table')->set(['columnA' => 'a'])->set(['columnB' => 'b'])->where(...);

The delete function only expects the from and where clause to identify the to delete columns in a table.

$query->prefix(...)->delete()->from('table')->where(...);

Random

From

The from part of a query accepts string, array, \Closure, From, Builder as parameter.

$query->prefix(...)->select(...)->from('table');
$query->prefix(...)->select(...)->from('tableA', 'tableB');

Into

The into part of a query accepts string, array, \Closure, Into, Builder as parameter.

Where

The basic where clause expects a column, operator, value and boolean concatenater which is used to concatenate multiple where clauses.

$query->prefix(...)->select(...)->from(...)->where('columnA', '=', 123)->where('columnB', '=', 'abc', 'or');

For easier use additional where clauses are defined such as:

• orWhere() - same as where with or as default boolean connector
• andWhere() - same as where with and as default boolean connector
• whereIn() - uses the sql in(...)
• whereNull() - used for null condition
• whereNotNull() - used for not null condition

Limit

The limit expects an integer.

$query->prefix(...)->select(...)->from(...)->where(...)->limit(3);

Offset

The offset expects an integer.

$query->prefix(...)->select(...)->from(...)->where(...)->offset(3);

Order

The ordering is performed by orderBy.

$query->prefix(...)->select(...)->from(...)->where(...)->orderBy('columnA', 'DESC');

The newest and oldest operation are a small wrapper which automatically order by DESC and ASC respectively.

Group By

Grouping of columns can be achieved through groupBy.

$query->prefix(...)->select(...)->from(...)->where(...)->groupBy('columnA', 'columnB');

Join

Schema Builder

The schema builder is used for schema related operations such as DROP, CREATE etc.