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Extending HCL OneDB™Beyond standard relational database objects, HCL OneDB™ can be extended to handle specialized data types, access methods, routines, and other objects. HCL OneDB™ includes many built-in extensions that are fully integrated in the database server. HCL OneDB™ also provides DataBlade® modules, which are packages of extended database objects for a particular purpose and that are installed separately from the database server. Alternatively, you can create your own user-defined objects for HCL OneDB™.
Creating extensionsYou can create user-defined data types, routines, access methods, and other database objects to suit your needs. You can use application programming interfaces to write user-defined routines and applications that access data in HCL OneDB™ databases.
DataBlade® API Function ReferenceThe HCL OneDB™ DataBlade® API Function Reference describes the DataBlade® API functions and the subset of functions that the DataBlade® API supports.
Function descriptionsThis section gives comprehensive reference information about the functions that are valid within DataBlade® API modules. It lists the function descriptions in alphabetical order, with syntax, usage information, and return values for the functions.
The mi_column_precision() functionThe mi_column_precision() function obtains the precision of the specified column from a row descriptor.

The mi_column_precision() function

The mi_column_precision() function obtains the precision of the specified column from a row descriptor.

Syntax

mi_integer mi_column_precision(row_desc, column_id)
   MI_ROW_DESC *row_desc;
   mi_integer column_id;

row_desc: A pointer to the row descriptor of the row that contains the column.
column_id: The column identifier, which specifies the position of the column in the specified row descriptor. Column numbering follows C array-indexing conventions: the first column in the row is at position zero.


Valid in client LIBMI application?	Valid in user-defined routine?
Yes	Yes

Usage

A row descriptor can describe the structure of a row in a table or the structure of a row type. From the row descriptor that row_desc references, the mi_column_precision() function obtains the precision of a column for either structure:

The precision of the column at position column_id in the row
The precision of the field at position column_id for the row type

The precision is an attribute of the column data type and represents the total number of digits the column can hold, as follows.

DECIMAL, MONEY: Number of significant digits in the fixed-point or floating-point (DECIMAL) column
DATETIME, INTERVAL: Number of digits that are stored in the date and/or time column with the specified qualifier
Character, Varying-character: Maximum number of characters in the column

If you call mi_column_precision() on a column or row-type field of some other data type, the function returns zero.

For more information about row descriptors or about the precision of a fixed-point data type, see the HCL OneDB™ DataBlade® API Programmer's Guide.

Return values

0: No precision was set for the specified column or field.
>0: The precision of the specified column or field.
MI_ERROR: The function was not successful.