COM_STMT_EXECUTE

COM_STMT_EXECUTE asks the server to execute a prepared statement as identified by statement_id.

It sends the values for the placeholders of the prepared statement (if it contained any) in Binary Protocol Value form. The type of each parameter is made up of two bytes:

• the type as in enum_field_types
• a flag byte which has the highest bit set if the type is unsigned [80]

The num_params used for this packet refers to num_params of the COM_STMT_PREPARE_OK of the corresponding prepared statement.

The server will use the first num_params (from prepare) parameter values to satisfy the positional anonymous question mark parameters in the statement executed regardless of whether they have names supplied or not. The rest num_remaining_attrs parameter values will just be stored into the THD and if they have a name they can later be accessed as query attributes. If any of the first num_params parameter values has a name supplied they could then be accessed as a query attribute too. If supplied, parameter_count will overwrite the num_params value by eventually adding a non-zero num_params_remaining value to the original num_params.

Returns

COM_STMT_EXECUTE Response

Payload

Type	Name	Description
int<1>	status	[0x17] COM_STMT_EXECUTE
int<4>	statement_id	ID of the prepared statement to execute
int<1>	flags	Flags. See enum_cursor_type
int<4>	iteration_count	Number of times to execute the statement. Currently always 1.
if (num_params > 0 || (CLIENT_QUERY_ATTRIBUTES && (flags & PARAMETER_COUNT_AVAILABLE)) {
if CLIENT_QUERY_ATTRIBUTES is on {
int<lenenc>	parameter_count	The number of parameter metadata and values supplied. Overrides the count coming from prepare (num_params) if present.
} – if CLIENT_QUERY_ATTRIBUTES is on
if (parameter_count > 0) {
binary<var>	null_bitmap	NULL bitmap, length= (paramater_count + 7) / 8
int<1>	new_params_bind_flag	Flag if parameters must be re-bound
if new_params_bind_flag, for each parameter {
int<2>	parameter_type	Type of the parameter value. See enum_field_type
if CLIENT_QUERY_ATTRIBUTES is on {
string<lenenc>	parameter_name	Name of the parameter or empty if not present
} – if CLIENT_QUERY_ATTRIBUTES is on
} – if new_params_bind_flag is on
binary<var>	parameter_values	value of each parameter
} – if (parameter_count > 0)
} – if (num_params > 0 || (CLIENT_QUERY_ATTRIBUTES && (flags & PARAMETER_COUNT_AVAILABLE))

Example

12 00 00 00 17 01 00 00    00 00 01 00 00 00 00 01    ................
0f 00 03 66 6f 6f                                     ...foo

null_bitmap is like the NULL-bitmap for the Binary Protocol Resultset Row just that it has a bit_offset of 0.

See also

mysql_stmt_execute, cli_stmt_execute, mysql_stmt_precheck, mysqld_stmt_execute