25.2.7.20. mysql_stmt_prepare()
int mysql_stmt_prepare(MYSQL_STMT *stmt, const char
*query, unsigned long length)
Description
Given the statement handle returned by
mysql_stmt_init(), prepares the SQL
statement pointed to by the string query
and returns a status value. The string length should be given
by the length argument. The string must
consist of a single SQL statement. You should not add a
terminating semicolon (‘;’) or
\g to the statement.
The application can include one or more parameter markers in
the SQL statement by embedding question mark
(‘?’) characters into the SQL
string at the appropriate positions.
The markers are legal only in certain places in SQL
statements. For example, they are allowed in the
VALUES() list of an
INSERT statement (to specify column values
for a row), or in a comparison with a column in a
WHERE clause to specify a comparison value.
However, they are not allowed for identifiers (such as table
or column names), or to specify both operands of a binary
operator such as the = equal sign. The
latter restriction is necessary because it would be impossible
to determine the parameter type. In general, parameters are
legal only in Data Manipulation Language (DML) statements, and
not in Data Definition Language (DDL) statements.
The parameter markers must be bound to application variables
using mysql_stmt_bind_param() before
executing the statement.
Return Values
Zero if the statement was prepared successfully. Non-zero if
an error occurred.
Errors
-
CR_COMMANDS_OUT_OF_SYNC
Commands were executed in an improper order.
-
CR_OUT_OF_MEMORY
Out of memory.
-
CR_SERVER_GONE_ERROR
The MySQL server has gone away.
-
CR_SERVER_LOST
The connection to the server was lost during the query
-
CR_UNKNOWN_ERROR
An unknown error occurred.
If the prepare operation was unsuccessful (that is,
mysql_stmt_prepare() returns non-zero), the
error message can be obtained by calling
mysql_stmt_error().
Example
For the usage of mysql_stmt_prepare(),
refer to the Example from
Section 25.2.7.10, “mysql_stmt_execute()”.
