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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 CAST statementUse the CREATE CAST statement to register a cast that converts data from one data type to another.
Explicit and Implicit CastsProcessing queries with multiple data types often requires casts that convert data from one data type to another.
Explicit CastsAn explicit cast is a cast that you must specifically invoke, with either the CAST AS keywords or with the cast operator ( :: ). The database server does not automatically invoke an explicit cast to resolve data type conversions. The EXPLICIT keyword is optional; by default, the CREATE CAST statement creates an explicit cast.

Explicit Casts

An explicit cast is a cast that you must specifically invoke, with either the CAST AS keywords or with the cast operator ( :: ). The database server does not automatically invoke an explicit cast to resolve data type conversions. The EXPLICIT keyword is optional; by default, the CREATE CAST statement creates an explicit cast.

The following CREATE CAST statement defines an explicit cast from the rate_of_return opaque data type to the percent distinct data type:

CREATE EXPLICIT CAST (rate_of_return AS percent 
   WITH rate_to_prcnt);

The following SELECT statement explicitly invokes this explicit cast in its WHERE clause to compare the bond_rate column (of type rate_of_return) to the initial_APR column (of type percent):

SELECT bond_rate FROM bond
   WHERE bond_rate::percent > initial_APR;