Command

The GdaCommand structure holds data needed to issue a command to the providers. Applications usually create a GdaCommand (via gda_command_new), set its properties (via the gda_command_set_* functions) and pass it over to the database using the GdaConnection functions.

One interesting thing about GdaCommand's is that they can be reused over and over. That is, applications don't need to create a command every time they want to run something on the connected database. Moreover, the ability to create command strings with placeholders allows the use of parameters to specify the values for those placeholders. Thus, an application can create a command of the form:

INSERT INTO employees VALUES (id, name, address, salary)

and reuse the same command over and over, just using different values for the placeholders.

The value for the placeholders is specified when sending the GdaCommand to a database connection, which is done via the gda_connection_execute function.

class Command {

protected

GdaCommand* gdaCommand;

GdaCommand* getCommandStruct();

void* getStruct();

this(GdaCommand* gdaCommand);

static GType getType();

this(string text, GdaCommandType type, GdaCommandOptions options);

void free();

Command copy();

string getText();

void setText(string text);

GdaCommandType getCommandType();

void setCommandType(GdaCommandType type);

GdaCommandOptions getOptions();

void setOptions(GdaCommandOptions options);

Transaction getTransaction();

void setTransaction(Transaction xaction);

}

Constructors

this this(GdaCommand* gdaCommand): Sets our main struct and passes it to the parent class
this this(string text, GdaCommandType type, GdaCommandOptions options): Creates a new GdaCommand from the parameters that should be freed by calling gda_command_free. If there are conflicting options, this will set options to GDA_COMMAND_OPTION_DEFAULT.

Members

Functions

copy Command copy(): Creates a new GdaCommand from an existing one.
free void free(): Frees the resources allocated by gda_command_new.
getCommandStruct GdaCommand* getCommandStruct(): Get the main Gtk struct
getCommandType GdaCommandType getCommandType(): Gets the command type of cmd.
getOptions GdaCommandOptions getOptions(): Gets the command options of cmd.
getStruct void* getStruct(): the main Gtk struct as a void*
getText string getText(): Gets the command text held by cmd.
getTransaction Transaction getTransaction(): Gets the GdaTransaction associated with the given GdaCommand.
setCommandType void setCommandType(GdaCommandType type): Sets the command type of cmd.
setOptions void setOptions(GdaCommandOptions options): Sets the command options of cmd. If there conflicting options, it will just leave the value as before.
setText void setText(string text): Sets the command text of cmd.
setTransaction void setTransaction(Transaction xaction): Sets the GdaTransaction associated with the given GdaCommand.

Static functions

getType GType getType()

Variables

gdaCommand GdaCommand* gdaCommand;: the main Gtk struct