Type Identifiers

A type identifier, MI_TYPEID, is a DataBlade API data type structure that identifies a data type uniquely. For extended data types, the type identifier is database-dependent; that is, the same type identifier might identify different data types for different databases. You can determine the data type that a type identifier represents with the following DataBlade API functions.

Type-Identifier Check	DataBlade API Function
Are two type identifiers equal?	mi_typeid_equals( )
Does the type identifier represent a built-in data type?	mi_typeid_is_builtin( )
Does the type identifier represent a collection (SET, MULTISET, LIST) data type?	mi_typeid_is_collection( )
Does the type identifier represent a complex data type (row type or collection)?	mi_typeid_is_complex( )
Does the type identifier represent a distinct data type?	mi_typeid_is_distinct( )
Does the type identifier represent a LIST data type?	mi_typeid_is_list( )
Does the type identifier represent a MULTISET data type?	mi_typeid_is_multiset( )
Does the type identifier represent a row type (named or unnamed)?	mi_typeid_is_row( )
Does the type identifier represent a SET data type?	mi_typeid_is_set( )

Type-Identifier Check

DataBlade API Function

Are two type identifiers equal?

mi_typeid_equals( )

Does the type identifier represent a built-in data type?

mi_typeid_is_builtin( )

Does the type identifier represent a collection (SET, MULTISET, LIST) data type?

mi_typeid_is_collection( )

Does the type identifier represent a complex data type (row type or collection)?

mi_typeid_is_complex( )

Does the type identifier represent a distinct data type?

mi_typeid_is_distinct( )

Does the type identifier represent a LIST data type?

mi_typeid_is_list( )

Does the type identifier represent a MULTISET data type?

mi_typeid_is_multiset( )

Does the type identifier represent a row type (named or unnamed)?

mi_typeid_is_row( )

Does the type identifier represent a SET data type?

mi_typeid_is_set( )

Important:

To a DataBlade API module, the type identifier (MI_TYPEID) is an opaque C data structure. Do not access its internal fields directly. The internal structure of a type identifier may change in future releases. Therefore, to create portable code, always use the accessor functions for this structure to determine data type.

The DataBlade API uses type identifiers in the following situations.

Type Identifier Usage	DataBlade API Function	More Information
To indicate a column type in a row descriptor	mi_column_type_id( )	Obtaining Column Information
To indicate data type of arguments in a user-defined routine (UDR)	mi_fp_argtype( ), mi_fp_setargtype( )	Determining the Data Type of UDR Arguments
To indicate data type of return type of a UDR	mi_fp_rettype( ), mi_fp_setrettype( )	Determining the Data Type of UDR Return Values
To indicate data type of a column with which an input parameter in a prepared statement is associated	mi_parameter_type_id( )	Obtaining Input-Parameter Information
To identify a UDR by the data types of its arguments to generate its function descriptor	mi_routine_get_by_typeid( )	Looking Up UDRs
To identify a cast function by the source and target data types to generate its function descriptor	mi_cast_get( )	Looking Up Cast Functions
To identify the element type of a collection	mi_collection_create( )	Creating a Collection

Type Identifier Usage

DataBlade API Function

More Information

To indicate a column type in a row descriptor

mi_column_type_id( )

Obtaining Column Information

To indicate data type of arguments in a user-defined routine (UDR)

mi_fp_argtype( ),
mi_fp_setargtype( )

Determining the Data Type of UDR Arguments

To indicate data type of return type of a UDR

mi_fp_rettype( ),
mi_fp_setrettype( )

Determining the Data Type of UDR Return Values