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SQL programmingYou can use the HCL OneDB™ implementation of the SQL language to develop applications for HCL OneDB™ database servers.
Guide to SQL: SyntaxThe HCL OneDB™ Guide to SQL: Syntax describes the syntax of the statements, data types, expressions, operators, and built-in functions of the HCL OneDB™ dialect of the SQL language.
SQL statementsThis chapter describes the syntax and semantics of SQL statements that are recognized by HCL OneDB™.
CREATE TABLE statementUse the CREATE TABLE statement to create a new permanent table in the current database.
OF TYPE ClauseUse the OF TYPE clause to create a typed table for an object-relational database. A typed table is a table in which every row is an object of the named ROW data type that you specify in this clause.
Using the UNDER Clause

Using the UNDER Clause

Use the UNDER clause to specify inheritance (that is, define the new table as a subtable). The subtable inherits properties from the specified supertable. In addition, you can define new properties specific to the subtable.

Continuing the example shown in OF TYPE Clause, the following statements create a typed table, grad_students, that inherits all of the columns of the students table but also has columns for adviser and field_of_study that correspond to fields in the grad_student_t ROW type:

CREATE ROW TYPE grad_student_t 
   (adviser        CHAR(25),
    field_of_study CHAR(40)) UNDER student_t;

CREATE TABLE grad_students OF TYPE grad_student_t  UNDER students;

When you use the UNDER clause, the subtable inherits these properties:

All columns in the supertable
All constraints defined on the supertable
All indexes defined on the supertable
All triggers defined on the supertable.
All referential integrity constraints
The access method
The storage option specification (including fragmentation strategy)
If a subtable defines no fragments, but if its supertable has fragments defined, then the subtable inherits the fragments of the supertable.

Tip: Any heritable attributes that are added to a supertable after subtables have been created are automatically inherited by existing subtables. You do not need to add all heritable attributes to a supertable before you create its subtables.