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bool mysql_stmt_send_long_data(MYSQL_STMT *stmt, unsigned int parameter_number, const char *data, unsigned long length) Enables an application to send parameter data to the server in pieces (or “chunks”). Call this function after mysql_stmt_bind_param() or mysql_stmt_bind_named_param() and before mysql_stmt_execute(). It can be called multiple times to send the parts of a character or binary data value for a column, which must be one of the TEXT or BLOB data types.
parameter_number indicates which parameter to associate the data with. Parameters are numbered beginning with 0. data is a pointer to a buffer containing data to be sent, and length indicates the number of bytes in the buffer.
Note
The next mysql_stmt_execute() call ignores the bind buffer for all parameters that have been used with mysql_stmt_send_long_data() since last mysql_stmt_execute() or mysql_stmt_reset().
To reset/forget the sent data, call mysql_stmt_reset(). See Section 6.4.23, “mysql_stmt_reset()”.
The max_allowed_packet system variable controls the maximum size of parameter values that can be sent with mysql_stmt_send_long_data().
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The parameter does not have a string or binary type.
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Invalid parameter number.
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Commands were executed in an improper order.
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The MySQL server has gone away.
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Out of memory.
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An unknown error occurred.
The following example demonstrates how to send the data for a TEXT column in chunks. It inserts the data value 'MySQL - The most popular Open Source database' into the text_column column. The mysql variable is assumed to be a valid connection handler.
#define INSERT_QUERY "INSERT INTO \ test_long_data(text_column) VALUES(?)" MYSQL_BIND bind[1]; long length; stmt = mysql_stmt_init(mysql); if (!stmt) { fprintf(stderr, " mysql_stmt_init(), out of memory\n"); exit(0); } if (mysql_stmt_prepare(stmt, INSERT_QUERY, strlen(INSERT_QUERY))) { fprintf(stderr, "\n mysql_stmt_prepare(), INSERT failed"); fprintf(stderr, "\n %s", mysql_stmt_error(stmt)); exit(0); } memset(bind, 0, sizeof(bind)); bind[0].buffer_type= MYSQL_TYPE_STRING; bind[0].length= &length; bind[0].is_null= 0; /* Bind the buffers */ if (mysql_stmt_bind_named_param(stmt, bind, 1, NULL)) { fprintf(stderr, "\n param bind failed"); fprintf(stderr, "\n %s", mysql_stmt_error(stmt)); exit(0); } /* Supply data in chunks to server */ if (mysql_stmt_send_long_data(stmt,0,"MySQL",5)) { fprintf(stderr, "\n send_long_data failed"); fprintf(stderr, "\n %s", mysql_stmt_error(stmt)); exit(0); } /* Supply the next piece of data */ if (mysql_stmt_send_long_data(stmt,0, " - The most popular Open Source database",40)) { fprintf(stderr, "\n send_long_data failed"); fprintf(stderr, "\n %s", mysql_stmt_error(stmt)); exit(0); } /* Now, execute the query */ if (mysql_stmt_execute(stmt)) { fprintf(stderr, "\n mysql_stmt_execute failed"); fprintf(stderr, "\n %s", mysql_stmt_error(stmt)); exit(0); }