PrevUpHomeGNOME Data Access manualNext

GdaDataModelHash

Name

GdaDataModelHash -- An implementation of GdaDataModel based on a hash table.

Synopsis



struct      GdaDataModelHashPrivate;
GdaDataModel* gda_data_model_hash_new       (gint cols);
const GdaValue* gda_data_model_hash_get_value_at
                                            (GdaDataModel *model,
                                             gint col,
                                             gint row);
void        gda_data_model_hash_clear       (GdaDataModelHash *model);
void        gda_data_model_hash_set_n_columns
                                            (GdaDataModelHash *model,
                                             gint cols);
void        gda_data_model_hash_insert_row  (GdaDataModelHash *model,
                                             gint rownum,
                                             GdaRow *row);
const GdaRow* gda_data_model_hash_get_row   (GdaDataModel *model,
                                             gint row);

Description

Unlike GdaDataModelArray, this data model implementation stores the GdaRow in a hash table. So it only retrieves from the database backend exactly the requested rows (while in GdaDataModelArray you have to retrieve all the rows until the one requested).

Details

struct GdaDataModelHashPrivate

struct GdaDataModelHashPrivate;

gda_data_model_hash_new ()

GdaDataModel* gda_data_model_hash_new       (gint cols);

cols :

number of columns for rows in this data model.

Returns :

A pointer to the newly created GdaDataModel.

gda_data_model_hash_get_value_at ()

const GdaValue* gda_data_model_hash_get_value_at
                                            (GdaDataModel *model,
                                             gint col,
                                             gint row);

Retrieve the value at a specified column and row.

model :

the GdaDataModelHash to retrieve the value from.

col :

column number (starting from 0).

row :

row number (starting from 0).

Returns :

a pointer to a GdaValue.

gda_data_model_hash_clear ()

void        gda_data_model_hash_clear       (GdaDataModelHash *model);

Frees all the rows inserted in model.

model :

the model to clear

gda_data_model_hash_set_n_columns ()

void        gda_data_model_hash_set_n_columns
                                            (GdaDataModelHash *model,
                                             gint cols);

Set the nunber of columns for rows inserted in this model. cols must be greater than or equal to 0.

This function calls gda_data_model_hash_clear to free the existing rows if any.

model :

the GdaDataModelHash which is gonna hold the row.

cols :

the number of columns for rows inserted in model.

gda_data_model_hash_insert_row ()

void        gda_data_model_hash_insert_row  (GdaDataModelHash *model,
                                             gint rownum,
                                             GdaRow *row);

Inserts a row in the model.

model :

the GdaDataModelHash which is gonna hold the row.

rownum :

the number of the row.

row :

the row to insert. The model is responsible of freeing it!

gda_data_model_hash_get_row ()

const GdaRow* gda_data_model_hash_get_row   (GdaDataModel *model,
                                             gint row);

Retrieves a row from the underlying hash table.

model :

the GdaDataModelHash

row :

row number

Returns :

a GdaRow or NULL if the requested row is not in the hash table.

<<< GdaDataModelArrayGdaDataModelList >>>