sql-generic-dql.c File Reference

#include <julea-config.h>
#include "sql-generic-internal.h"

Functions
gboolean	_backend_schema_get (gpointer backend_data, gchar const *namespace, gchar const *name, bson_t *schema, GError **error)
	Retrieve the schema as bson document. More...
GHashTable *	get_schema (gpointer backend_data, gchar const *namespace, gchar const *name, GError **error)
	Get the schema as a HashTable for internal usage. More...
gboolean	sql_generic_schema_get (gpointer backend_data, gpointer _batch, gchar const *name, bson_t *schema, GError **error)
gboolean	build_query_condition_part (gpointer backend_data, JSqlBatch *batch, bson_iter_t *iter, GString *sql, JDBSelectorMode mode, GArray *arr_types_in, GHashTable *variable_types, GError **error)
	Build the WHERE part of a SELECT statement from a selector. More...
gboolean	bind_selector_query (gpointer backend_data, const gchar *namespace, bson_iter_t *iter, JSqlStatement *statement, GHashTable *schema, GError **error)
	Bind the variables in the WHERE part of a SELECT statement. More...
gboolean	_backend_query_ids (gpointer backend_data, gpointer _batch, gchar const *name, bson_t const *selector, GArray **matches, GError **error)
	Query the IDs of rows that match a selector. More...
gboolean	sql_generic_query (gpointer backend_data, gpointer _batch, gchar const *name, bson_t const *selector, gpointer *iterator, GError **error)
gboolean	sql_generic_iterate (gpointer backend_data, gpointer _iterator, bson_t *query_result, GError **error)

Function Documentation

_backend_query_ids()

gboolean _backend_query_ids	(	gpointer	backend_data,
		gpointer	_batch,
		gchar const *	name,
		bson_t const *	selector,
		GArray **	matches,
		GError **	error
	)

Query the IDs of rows that match a selector.

It is is used in the update and delete functions.

Todo:

Update and delete could be done by adding the selection part to the respective query, making this function unnecessary.

Parameters

	backend_data	The backend-specific information to open a connection.
	_batch	A JSqlBatch object.
	name	The schema name.
	selector	A bson selector document sent by the client.
[out]	matches	A GArray of the matched IDs.
[out]	error	An uninitialized GError* for error code passing.

Returns

gboolean TRUE on success, FALSE otherwise.

Todo:

check if caching this statement makes any difference with different databases

_backend_schema_get()

gboolean _backend_schema_get	(	gpointer	backend_data,
		gchar const *	namespace,
		gchar const *	name,
		bson_t *	schema,
		GError **	error
	)

Retrieve the schema as bson document.

This format is suitable for answering schema requests by clients.

Parameters

	backend_data	The backend-specific information to open a connection.
	namespace	The namespace of the schema.
	name	The schema name.
[in,out]	schema	A bson document to be filled with schema information as a list of variable name and type pairs.
[out]	error	An uninitialized GError* for error code passing.

Returns

gboolean TRUE on success, FALSE otherwise.

bind_selector_query()

gboolean bind_selector_query	(	gpointer	backend_data,
		const gchar *	namespace,
		bson_iter_t *	iter,
		JSqlStatement *	statement,
		GHashTable *	schema,
		GError **	error
	)

Bind the variables in the WHERE part of a SELECT statement.

Parameters

backend_data	The backend-specific information to open a connection.
iter	An initialized iterator over the relevant part of the selector bson document. Should be retrieved the same way as for build_selector_query to ensure the same order of variables!
statement	A JSqlStatement which
schema	The database schema in hash table format.

Todo:

need to change this one for joins

Parameters

[out]

error

An uninitialized GError* for error code passing.

Returns

gboolean TRUE on success, FALSE otherwise.

build_query_condition_part()

gboolean build_query_condition_part	(	gpointer	backend_data,
		JSqlBatch *	batch,
		bson_iter_t *	iter,
		GString *	sql,
		JDBSelectorMode	mode,
		GArray *	arr_types_in,
		GHashTable *	schema,
		GError **	error
	)

Build the WHERE part of a SELECT statement from a selector.

Parameters

	backend_data	The backend-specific information to open a connection.
	iter	An initialized iterator over the relevant part of the selector bson document.
	batch	The batch of the operation.
[in,out]	sql	A GString to which the WHERE part of the query should be appended.
	mode	The mode of the selector (i.e., AND or OR).
	arr_types_in	An allocated GArray to which the found types will be appended.
	schema	The database schema in hash table format.

Todo:

need to change this one for joins

Parameters

[out]

error

An uninitialized GError* for error code passing.

Returns

gboolean TRUE on success, FALSE otherwise.

get_schema()

GHashTable* get_schema	(	gpointer	backend_data,
		gchar const *	namespace,
		gchar const *	name,
		GError **	error
	)

Get the schema as a HashTable for internal usage.

Uses a transparent cache for schemas.

Todo:

Currently _backend_schema_get is called and the returned bson is converted to a GHashTable. A better way would be to use one common function for both so no conversion is neccessary.

Parameters

	backend_data	The backend-specific information to open a connection if needed.
	namespace	The namespace of the schema.
	name	The schema name.
[out]	error	An uninitialized GError* for error code passing.

Returns

GHashTable* A valid GHashTable pointer on success or NULL otherwise. The hash table should by freed using g_hash_table_unref (or by using g_autoptr).

sql_generic_iterate()

gboolean sql_generic_iterate	(	gpointer	backend_data,
		gpointer	_iterator,
		bson_t *	query_result,
		GError **	error
	)

Todo:

Backend specific quotes need to be removed. There should be a better solution.

sql_generic_query()

gboolean sql_generic_query	(	gpointer	backend_data,
		gpointer	_batch,
		gchar const *	name,
		bson_t const *	selector,
		gpointer *	iterator,
		GError **	error
	)

sql_generic_schema_get()

gboolean sql_generic_schema_get	(	gpointer	backend_data,
		gpointer	_batch,
		gchar const *	name,
		bson_t *	schema,
		GError **	error
	)