These are examples taken from the mailing list.
Sub-select
Code Block |
---|
|
// Define the sub query
DBCommand subCmd = db.createCommand();
subCmd.select(...);
// Wrap command for subquery
DBQuery SQ = new DBQuery(subCmd);
// Define the main query
DBCommand cmd = db.createCommand();
cmd.select(..);
cmd.select(SQ.findQueryColumn(...));
cmd.join(..., SQ.findQueryColumn(...));
|
Self-joins
Code Block |
---|
|
SampleDB db = new SampleDB();
SampleDB.Departments DEP1 = new Departments(db);
SampleDB.Departments DEP2 = new Departments(db);
// Create the command
DBCommand cmd = db.createCommand();
cmd.select(DEP1.NAME, DEP2.NAME);
cmd.join (DEP1.DEPARTMENT_ID, DEP2.PARENT_ID);
String sql = cmd.getSelect();
|
Union
Code Block |
---|
|
DBCommandExpr union = cmd1.union(cmd2);
String sql = union.getSelect();
|