Next: pq_update_types, Up: Data exchange [Index]
Sends the string command, which must contain a single SQL
command, over the connection connection. Parameters in
command can be replaced by $1, $2, etc and their values given
in the one-dimensional cell-array params. Parameters of
composite type sent this way must have their type defined in the
database. For typeconversions, the package maintains a notion of
defined types, which should be refreshed with pq_update_types
if types are defined or dropped after establishing the connection, or
if the schema search path changes. settings is a structure of
settings, it can be created by setdbopts.
Settings currently understood by pq_exec_params:
param_typesOne-dimensional cell-array with type specifications for parameters in
params. If present, must have the same length as params.
Entries may be empty if no specification is necessary (see below).
Type specifications are strings corresponding to the entries returned
by SELECT typname FROM pg_type WHERE typarray != 0 OR typtype =
'c';, optionally having [] appended (without space) to
indicate an array. Type specifications can be schema-qualified,
otherwise they refer to the visible type with that name.
copy_in_path, copy_out_pathPath to files at the client side for copy from stdin and
copy to stdout, respectively.
copy_in_from_variableLogical scalar, default false. If true, copy from
stdin uses data from an Octave variable instead of from a file.
copy_in_data2-dimensional cell-array with columns of suitable type (see below) –
will be used instead of a file as data for copy from stdin if
copy_in_from_variable is true.
copy_in_typesIf some columns in copy_in_data need a type specification (see
below), copy_in_types has to be set to a cell-array with type
specifications, with an entry (possibly empty) for each column.
copy_in_with_oidsIf you want to copy in with oids when using data from an Octave
variable, the first column of the data must contain the OIDs and
copy_in_with_oids has to be set to true (default
false); with oids should be specified together with
copy from stdin in the command, otherwise Postgresql will
ignore the copied oids.
There is no way to copy to stdout into an Octave variable, but
a select command can be used for this purpose.
copy from stdin from an Octave variable is only supported in
binary mode, so this has to be specified in the SQL command.
The output depends on the type of command.
data (containing
a cell array with the data, columns correspond to returned database
columns, rows correspond to returned tuples), columns
(containing the column headers), and types (a
structure-vector with the postgresql data types of the columns,
subfields name (string with typename), is_array
(boolean), is_composite (boolean), is_enum (boolean),
and elements (if is_composite == true,
structure-vector of element types, containing fields corresponding
to those of types)).
See also: pq_update_types, pq_conninfo.
For the mapping of currently implemented Postgresql types to Octave types, see Postgresql data types.
Next: pq_update_types, Up: Data exchange [Index]