Interpret column-value status
The mi_value() and mi_value_by_name() functions return a value status, which identifies how to interpret the column value that these functions pass back.
The following table shows the kinds of column values that
these functions can identify.
| Type of column value | Value-status constant | More information |
|---|---|---|
| A built-in, opaque, or distinct data type | MI_NORMAL_VALUE | Obtain normal values |
| An SQL NULL value | MI_NULL_VALUE | Obtain NULL values |
| A row type | MI_ROW_VALUE | Obtain row values |
| A collection | MI_COLLECTION_VALUE | Obtain collection values |
You can use a switch statement based on these value-status constants to determine how to handle the column value.