The mi_value_by_name() function

Syntax

mi_integer mi_value_by_name(row, column_name, retbuf, retlen)
   MI_ROW *row;
   char *column_name;
   MI_DATUM *retbuf;
   mi_integer *retlen;

row

The row from which values are being extracted.

column_name

Name of the column for which the value is to be returned.

retbuf

A pointer to a location in the user space that is set to the address of a buffer that contains the returned value. This function allocates the buffer. You do not need to supply the buffer to contain the returned value.

retlen

The length of the returned column value.

Usage

The mi_value_by_name() function returns the value for the column that the column_name column name specifies. It retrieves this column value from the row structure that row references. The only difference between the mi_value_by_name() and mi_value() function is that the former accesses a column by its name while the latter accesses it by column identifier. Like mi_value(), the mi_value_by_name() function is typically called in a loop that terminates when mi_value_by_name() has retrieved values for all the columns in the row.

For more information about how to retrieve values, see the HCL OneDB™ DataBlade® API Programmer's Guide.

Return values

MI_NORMAL_VALUE

The retbuf value is not a row type or a collection. The mi_value_by_name() function places the value in retbuf.

MI_COLLECTION_VALUE

The retbuf value A pointer to a collection structure (MI_COLLECTION).

MI_ROW_VALUE

The retbuf value A pointer to a row structure (MI_ROW).

MI_NULL_VALUE

The retbuf value A NULL value.

MI_ERROR

The function was not successful.