Function: exec_metadata - Virtuoso Functions Guide

exec_metadata

Compiles a SQL statement and returns the metadata

exec_metadata (in str varchar, out state varchar, out message varchar, out metadata vector);

Description

This function provides dynamic SQL capabilities in Virtuoso PL. The first argument is an arbitrary SQL statement, which may contain parameter placeholders. The function returns as output parameters a SQL state, error message, column metadata if the statement is a select.

Parameters

str – A varchar containing arbitrary SQL using ?'s for parameter markers.

state – An output parameter of type varchar set to the 5 character SQL state if the exec resulted an error. Not set if an error is not present.

message – An output parameter of type varchar set to SQL error message associated with the error. Not set if an error is not present.

metadata – An output parameter of type vector returning the metadata of the statement and its result.

Table: 22.1. The stmt_meta array
Element	Name	Description
0	COLS	An array containing description of each column in the result set (see table below for contents)
1	STMT_SELECT	An integer 1 indicates that the statement is a select, otherwise it is a DML statement.
2..	N/A	Trailing elements may appear, but they should not be used

Table: 22.2. Columns array of metadata
Element	Name	Description
0	name	Column name
1	type	Column type as an internal type code corresponding, but not equal to ODBC SQL type codes.
2	scale	column scale
3	precision	column precision
4	nullable	indicates nullable column
5	updatable	indicates updatable column
6	searchable	indicates searchable column

Errors

The function will generate a SQL 22023 error value if a supplied parameter is not of the type expected.

22. Virtuoso Functions Guide - exec_metadata

exec_metadata