- Documentation Library
- Table of Contents
- MySQL 6.0 Reference Manual
- MySQL 5.1 Reference Manual
- MySQL 5.0 Reference Manual
- MySQL 3.23/4.0/4.1 Manual
- Table of Contents
- 29.7.7 C API Prepared Statement Function Descriptions
- 29.7.7.1 mysql_stmt_affected_rows()
- 29.7.7.2 mysql_stmt_attr_get()
- 29.7.7.3 mysql_stmt_attr_set()
- 29.7.7.4 mysql_stmt_bind_param()
- 29.7.7.5 mysql_stmt_bind_result()
- 29.7.7.6 mysql_stmt_close()
- 29.7.7.7 mysql_stmt_data_seek()
- 29.7.7.8 mysql_stmt_errno()
- 29.7.7.9 mysql_stmt_error()
- 29.7.7.10 mysql_stmt_execute()
- 29.7.7.11 mysql_stmt_fetch()
- 29.7.7.12 mysql_stmt_fetch_column()
- 29.7.7.13 mysql_stmt_field_count()
- 29.7.7.14 mysql_stmt_free_result()
- 29.7.7.15 mysql_stmt_init()
- 29.7.7.16 mysql_stmt_insert_id()
- 29.7.7.17 mysql_stmt_num_rows()
- 29.7.7.18 mysql_stmt_param_count()
- 29.7.7.19 mysql_stmt_param_metadata()
- 29.7.7.20 mysql_stmt_prepare()
- 29.7.7.21 mysql_stmt_reset()
- 29.7.7.22 mysql_stmt_result_metadata()
- 29.7.7.23 mysql_stmt_row_seek()
- 29.7.7.24 mysql_stmt_row_tell()
- 29.7.7.25 mysql_stmt_send_long_data()
- 29.7.7.26 mysql_stmt_sqlstate()
- 29.7.7.27 mysql_stmt_store_result()
29.7.7.4. mysql_stmt_bind_param()
my_bool mysql_stmt_bind_param(MYSQL_STMT *stmt,
MYSQL_BIND *bind)
Description
mysql_stmt_bind_param() is used
to bind input data for the parameter markers in the SQL
statement that was passed to
mysql_stmt_prepare(). It uses
MYSQL_BIND structures to supply the data.
bind is the address of an array of
MYSQL_BIND structures. The client library
expects the array to contain one element for each
“?” parameter marker that is
present in the query.
Suppose that you prepare the following statement:
INSERT INTO mytbl VALUES(?,?,?)
When you bind the parameters, the array of
MYSQL_BIND structures must contain three
elements, and can be declared like this:
MYSQL_BIND bind[3];
Section 29.7.5, “C API Prepared Statement Data types”, describes
the members of each MYSQL_BIND element and
how they should be set to provide input values.
Return Values
Zero if the bind operation was successful. Non-zero if an error occurred.
Errors
-
CR_UNSUPPORTED_PARAM_TYPEThe conversion is not supported. Possibly the
buffer_typevalue is illegal or is not one of the supported types. -
CR_OUT_OF_MEMORYOut of memory.
-
CR_UNKNOWN_ERRORAn unknown error occurred.
Example
For the usage of
mysql_stmt_bind_param(), refer
to the Example from Section 29.7.7.10, “mysql_stmt_execute()”.
User Comments
The MYSQL_BIND array is only pointed to by the MYSQL_STMT so it must not be changed or freed until the MYSQL_STMT is either not used any more or rebound to a new MYSQL_BIND array.
The length of the BIND structure in v4.1.xx is 55 bytes.
The boundary must be aligned as per:
http://bugs.mysql.com/bug.php?id=8550
"... buffers that will store integer types need to be properly aligned, and unless you allocate every single buffer with an own "malloc" you risk getting an alignment error (sigbus)."
I found that adding a single byte variable to the declaration at the end like:
my_bool pad; /* Align boundary */
bringing the total bytes in the structure up to 56, cures the error I was getting:
Error: 2036 (CR_UNSUPPORTED_PARAM_TYPE)
Using unsupported buffer type: 0 (parameter: 2)
Because the variable buffer_type was not being read from the second element of the array in the expected location.
In Ver 5.1, this is not needed.
Mike Trader
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