GdaDataModel columns

GdaDataModel columns — Management of GdaDataModel column attributes

Stability Level

Stable, unless otherwise indicated

Properties

gchar * id Read / Write

Signals

void g-type-changed Run Last
void name-changed Run Last

Types and Values

Object Hierarchy

    GObject
    ╰── GdaColumn

Description

The GdaColumn object represents a GdaDataModel's column and handle all its properties.

Functions

gda_column_new ()

GdaColumn *
gda_column_new (void);

Returns

a newly allocated GdaColumn object.


gda_column_copy ()

GdaColumn *
gda_column_copy (GdaColumn *column);

Creates a new GdaColumn object from an existing one.

Parameters

column

column to get a copy from.

 

Returns

a newly allocated GdaColumn with a copy of the data in column .

[transfer full]


gda_column_get_name ()

const gchar *
gda_column_get_name (GdaColumn *column);

Parameters

column

a GdaColumn.

 

Returns

the name of column .


gda_column_get_description ()

const gchar *
gda_column_get_description (GdaColumn *column);

Parameters

column

a GdaColumn.

 

Returns

the column's description, in any


gda_column_get_dbms_type ()

const gchar *
gda_column_get_dbms_type (GdaColumn *column);

Parameters

column

a GdaColumn.

 

Returns

the database type of column .


gda_column_get_g_type ()

GType
gda_column_get_g_type (GdaColumn *column);

Parameters

column

a GdaColumn.

 

Returns

the type of column .


gda_column_get_allow_null ()

gboolean
gda_column_get_allow_null (GdaColumn *column);

Gets the 'allow null' flag of the given column.

Parameters

column

a GdaColumn.

 

Returns

whether the given column allows null values or not (TRUE or FALSE).


gda_column_get_auto_increment ()

gboolean
gda_column_get_auto_increment (GdaColumn *column);

Parameters

column

a GdaColumn.

 

Returns

whether the given column is an auto incremented one (TRUE or FALSE).


gda_column_get_position ()

gint
gda_column_get_position (GdaColumn *column);

Parameters

column

a GdaColumn.

 

Returns

the position of the column refer to in the containing data model.


gda_column_get_default_value ()

const GValue *
gda_column_get_default_value (GdaColumn *column);

Parameters

column

a GdaColumn.

 

Returns

column 's default value, as a GValue object, or NULL if column does not have a default value.

[allow-none]


gda_column_get_attribute ()

const GValue *
gda_column_get_attribute (GdaColumn *column,
                          const gchar *attribute);

Get the value associated to a named attribute.

Attributes can have any name, but Libgda proposes some default names, see this section.

Parameters

column

a GdaColumn

 

attribute

attribute name as a string

 

Returns

a read-only GValue, or NULL if not attribute named attribute has been set for column


gda_column_set_attribute ()

void
gda_column_set_attribute (GdaColumn *column,
                          const gchar *attribute,
                          const GValue *value,
                          GDestroyNotify destroy);

Set the value associated to a named attribute. The attribute string is 'stolen' by this method, and the memory it uses will be freed using the destroy function when no longer needed (if destroy is NULL, then the string will not be freed at all).

Attributes can have any name, but Libgda proposes some default names, see this section.

If there is already an attribute named attribute set, then its value is replaced with the new value (value is copied), except if value is NULL, in which case the attribute is removed.

For example one would use it as:

gda_column_set_attribute (holder, g_strdup (my_attribute), g_free, my_value); gda_column_set_attribute (holder, GDA_ATTRIBUTE_NAME, NULL, my_value);

Note: this method does not modify in any way the contents of the data model for which column is a column (nor does it modify the table definition of the tables used by a SELECT statement is the model was created from a SELECT statement).

Parameters

column

a GdaColumn

 

attribute

attribute name as a static string

 

value

a GValue, or NULL.

[allow-none]

destroy

a function to be called when attribute is not needed anymore, or NULL.

[allow-none]

gda_column_set_attribute_static()

#define gda_column_set_attribute_static(holder,attribute,value) gda_column_set_attribute((holder),(attribute),(value),NULL)

This function is similar to gda_column_set_attribute() but for static strings

Parameters

holder

a GdaHolder

 

attribute

attribute's name

 

value

the value to set the attribute to, or NULL.

[allow-none]

Types and Values

GdaColumn

typedef struct _GdaColumn GdaColumn;

Property Details

The “id” property

  “id”                       gchar *

Column's Id (warning: the column's ID is not guaranteed to be unique in a GdaDataModel).

Flags: Read / Write

Default value: NULL

Signal Details

The “g-type-changed” signal

void
user_function (GdaColumn *column,
               GType     *old_type,
               GType     *new_type,
               gpointer   user_data)

Gets emitted whenever column 's type has been changed

Parameters

column

the GdaColumn object

 

old_type

the column's previous type

 

new_type

the column's new type

 

user_data

user data set when the signal handler was connected.

 

Flags: Run Last


The “name-changed” signal

void
user_function (GdaColumn *column,
               gchar     *old_name,
               gpointer   user_data)

Gets emitted whenever column 's name has been changed

Parameters

column

the GdaColumn object

 

old_name

the column's previous name

 

user_data

user data set when the signal handler was connected.

 

Flags: Run Last

See Also

GdaDataModel