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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.
Data types and expressionsThese topics describe the data types and expressions that HCL OneDB™supports.
Expression
Column ExpressionsA column expression specifies a data value in a column in the database, or a substring of the value, or a field within a ROW-type column, or a field in a BSON column.
Using Dot Notation
Selecting Nested Fields

Selecting Nested Fields

When the ROW type that defines a column itself contains other ROW types, the column contains nested fields. Use dot notation to access these nested fields within a column.

For example, assume that the address column of the employee table contains the fields: street, city, state, and zip. In addition, the zip field contains the nested fields: z_code and z_suffix. A query on the zip field returns values for the z_code and z_suffix fields. You can specify, however, that a query returns only specific nested fields. The following example shows how to use dot notation to construct a SELECT statement that returns rows for the z_code field of the address column only:

SELECT address.zip.z_code 
   FROM employee;