ToC path:

mco_dict_ifield

Return an index field descriptor.

Prototype

 
    MCO_RET mco_dict_ifield(	/*IN*/ mco_metadict_header_t * metadict, 
                  /*IN*/ unsigned short dict_no,
                  /*IN*/ unsigned short struct_no,
                  /*IN*/ unsigned short index_no, 
                  /*IN*/ unsigned short ifield_no,
                  /*OUT*/ mco_dict_ifield_info_t * ifield_info );

Arguments

metadict	The address of an initialized mco_metadict_header_t structure
dict_no	The number of the dictionary (must be between 0 and `mco_metadict_count()` - 1)
struct_no	The structure/class number (must be between 0 and `mco_dict_struct_count()` - 1)
index_no	The index number (must be between 0 and `struct_info.index_count` - 1)
ifield_no	The compound index field (segment) number (0 and `index_info.n_fields` - 1)
ifield_info	The address of a `mco_dict_ifield_info_t` variable to receive the index field descriptor

Description

This function returns a compound index field (segment) descriptor by index field number ifield_no.

Return Codes

MCO_S_OK	The index field descriptor was successfully returned
MCO_E_UDA_DICT_NOTFOUND	The dictionary is not registered
MCO_E_UDA_STRUCT_NOTFOUND	Invalid `struct_no`
MCO_E_UDA_STRUCT_NOT_CLASS	Invalid `struct_no` (not a class)
MCO_E_UDA_INDEX_NOTFOUND	Invalid `index_no`
MCO_E_UDA_IFIELD_NOTFOUND	Invalid index field (segment) number `ifield_no`

Example

 
    Application snippet:
        
     
    const char * dbname = "SimpleDb";
     
    int main(int argc, char* argv[])
    {
        MCO_RET rc;
        unsigned int dict_no = 0;
        unsigned int struct_no = 0;
        unsigned int index_no = 0;
        unsigned int count;
        mco_metadict_header_t *header;
        mco_dict_index_info_t index_info;
 
        ...
         
        header = (mco_metadict_header_t *) malloc(size);
        mco_metadict_init(header, size); /* initialize the metadict */
        ...
        rc = mco_dict_index(header, dict_no, struct_no, index_no, &index_info);
        for (i = 0; i < index_info.n_fields; ++i)
        {
            mco_dict_ifield_info_t ifield_info;
            mco_dict_field_info_t field_info;
            /* get index field descriptor */
            rc = mco_dict_ifield(header, dict_no, struct_no, index_no, i, &ifield_info);
        
            rc = mco_dict_field(header, dict_no, struct_no, ifield_info.field_no, &field_info);
            printf("Compound index field %d : %s\n", i, field_info.name);
        }
        ...
    }

Files

Header file:

mcouda.h

Source file:

mcouda.c

Library:

libmcouda.a