25.2.7.5. mysql_stmt_bind_result()
my_bool mysql_stmt_bind_result(MYSQL_STMT *stmt,
MYSQL_BIND *bind)
Description
mysql_stmt_bind_result() is used to
associate (bind) columns in the result set to data buffers and
length buffers. When mysql_stmt_fetch() is
called to fetch data, the MySQL client/server protocol places
the data for the bound columns into the specified buffers.
All columns must be bound to buffers prior to calling
mysql_stmt_fetch(). bind
is the address of an array of MYSQL_BIND
structures. The client library expects the array to contain an
element for each column of the result set. If you do not bind
columns to MYSQL_BIND structures,
mysql_stmt_fetch() simply ignores the data
fetch. The buffers should be large enough to hold the data
values, because the protocol doesn't return data values in
chunks.
A column can be bound or rebound at any time, even after a
result set has been partially retrieved. The new binding takes
effect the next time mysql_stmt_fetch() is
called. Suppose that an application binds the columns in a
result set and calls mysql_stmt_fetch().
The client/server protocol returns data in the bound buffers.
Then suppose that the application binds the columns to a
different set of buffers. The protocol does not place data
into the newly bound buffers until the next call to
mysql_stmt_fetch() occurs.
To bind a column, an application calls
mysql_stmt_bind_result() and passes the
type, address, and the address of the length buffer. The
members of each MYSQL_BIND element that
should be set are described in
Section 25.2.5, “C API Prepared Statement Data types”.
Return Values
Zero if the bind was successful. Non-zero if an error
occurred.
Errors
-
CR_UNSUPPORTED_PARAM_TYPE
The conversion is not supported. Possibly the
buffer_type value is illegal or is not
one of the supported types.
-
CR_OUT_OF_MEMORY
Out of memory.
-
CR_UNKNOWN_ERROR
An unknown error occurred.
Example
For the usage of mysql_stmt_bind_result(),
refer to the Example from Section 25.2.7.11, “mysql_stmt_fetch()”.
