Parameter descriptor
A parameter descriptor, or MI_AM_PARAM_DESC structure, describes a parameter in a qualification descriptor.
Use the VTI mi_qual_param() function to obtain a pointer to the parameter descriptor from the qualification descriptor
The following accessor functions extract information
from a parameter descriptor.
| Accessor function | Return value |
|---|---|
| mi_qual_param_column() | The position that the column associated with a parameter occupies within a row |
| mi_qual_param_constant() | The runtime value of the constant associated with a parameter |
| mi_qual_param_constant_typeid() | The data type of the constant associated with a parameter |
| mi_qual_param_constisnull() | MI_TRUE if the value of the constant associated with a parameter is NULL |
| mi_qual_param_expression() | A pointer to the qualification descriptor for the parameter that is associated with an expression. |
| mi_qual_param_expression_isnull() | MI_TRUE if the value of the expression associated with a parameter is NULL |
| mi_qual_param_expression_typeid() | The data type of the value of the expression associated with a parameter |
| mi_qual_param_expression_value() | The resulting value of the expression |
| mi_qual_param_iscolumn() | MI_TRUE if the parameter is associated with a column |
| mi_qual_param_isconstant() | MI_TRUE if the parameter is associated with a constant |
| mi_qual_param_isexpression() | MI_TRUE if the parameter is associated with an expression |
| mi_qual_param_issimple() | MI_TRUE if the parameter is associated with a column or a constant |
The following accessor function sets values in the descriptor.
| Accessor function | Value set |
|---|---|
| mi_qual_param_expression_setvalue() | The result from executing the expression |