Rows.length is null or not an object

Should the text within the brackets be double quoted? After taking another look, I noticed there was a second comma after the second value, replaced that and used double quotes and it worked. So now that this is working with Server Side, I find it too slow. So I would like to go back to the Ajax method as it seemed to work a lot faster. So I am back to the original issue I described. Fair enough - that's the draw back of using server-side processing.

The HTTP session can have considerable latency So with the original issue - are you using the expect json format? Can you provide an example of what you are using? Thanks Allan. I'm not entirely sure what you mean? I am using a PHP script to write the json, as the data is dynamic for the data table, it works when it comes through, minus what I said in the original post.

Dont want to have to do that. With the exception that it only needs to output two columns instead of four. If I recall, I used the php script supplied in 1. I copied my alteration that I was trying to get to run. Which of the following expression filters the rows whose column B values are greater than 45? What does the aggregate method shown in below code do?

Which of the following argument is used to ignore the index while concatenating two data frames? Questions in the final assessment are from the above questions only. Facebook Twitter. Try to understand these solutions and solve your Hands-On problems.

Not encourage copy and paste these solutions. Answer: 2 c You can define constraints on an object table just as you can on other tables. You can define constraints on the leaf-level scalar attributes of a column object, with the exception of REF s that are not scoped. Example and Example illustrate the possibilities. You can define indexes on an object table or on the storage table for a nested table column or attribute just as you can on other tables.

For an example of an index on a nested table, see Example You can define indexes on leaf-level scalar attributes of column objects, as shown in Example Wherever Oracle expects a column name in an index definition, you can also specify a scalar attribute of an object column. You can define triggers on an object table just as you can on other tables. You cannot define a trigger on the storage table for a nested table column or attribute.

You cannot modify LOB values in a trigger body. Otherwise, there are no special restrictions on using object types with triggers. Example Creating a Trigger on Objects in a Table. When a REF column is unconstrained, it may store object references to row objects contained in any object table of the corresponding object type.

Oracle does not ensure that the object references stored in such columns point to valid and existing row objects. Therefore, REF columns may contain object references that do not point to any existing row object. Such REF values are referred to as dangling references. A REF column may be constrained to be scoped to a specific object table.

The REF values may, however, be dangling. The rules for referential constraints apply to such columns. That is, the object reference stored in these columns must point to a valid and existing row object in the specified object table. Oracle SQL lets you omit qualifying table names in some relational operations.

Using the dot notation, you can qualify the column names with table names or table aliases to make things more maintainable. For example:. Using unqualified names can lead to problems. If you add an assignment column to depts and forget to change the query, Oracle automatically recompiles the query such that the inner SELECT uses the assignment column from the depts table. This situation is called inner capture. To avoid inner capture and similar problems resolving references, Oracle requires you to use a table alias to qualify any dot-notational reference to methods or attributes of objects.

Use of a table alias is optional when referencing top-level attributes of an object table directly, without using the dot notation. The following queries show some correct and incorrect ways to reference attribute idno :. It references this top-level attribute directly, without using the dot notation, so no table alias is required. This is incorrect; a table alias is required. You must qualify a reference to an object attribute or method with a table alias rather than a table name even if the table name is itself qualified by a schema name.

The same requirement applies to attribute references that use REF s. Table aliases should uniquely pick out the same table throughout a query and should not be the same as schema names that could legally appear in the query.

You cannot use a database link to do any of the following:. Connect to a remote database to select, insert, or update a user-defined type or an object REF on a remote table. Methods are functions or procedures that you can declare in an object type definition to implement behavior that you want objects of that type to perform. An application calls the methods to invoke the behavior.

In SQL, the parentheses are required for all method calls. Methods written in other languages, such as C, are stored externally. Member methods are the means by which an application gains access to an object instance's data. You define a member method in the object type for each operation that you want an object of that type to be able to perform. Member methods have a built-in parameter named SELF that denotes the object instance on which the method is currently being invoked.

Member methods can reference the attributes and methods of SELF without a qualifier. This makes it simpler to write member methods. In Example the code shows a method declaration that takes advantage of SELF to omit qualification of the attributes hgt , len , and wth. Example Creating a Member Method. SELF does not need to be explicitly declared, although it can be. It is always the first parameter passed to the method.

This notation specifies the object on which to invoke the method, then the method to call. Any parameters must be placed inside the required parentheses. To be able to compare and order variables of an object type, you must specify a basis for comparing them. Two special kinds of member methods can be defined for doing this: map methods and order methods. With a map method, you can order any number of objects by calling each object's map method once to map that object to a position on the axis used for the comparison, such as a number or date.

Example contains a simple map method. From the standpoint of writing one, a map method is simply a parameter-less member function that uses the MAP keyword and returns one of the datatypes just listed. The following example defines a map method area that provides a basis for comparing rectangle objects by their area:.

An object type can declare at most one map method or one order method. A subtype can declare a map method only if its root supertype declares one. See "Equal and Not Equal Comparisons" for the use of map methods when comparing collections that contain object types. Order methods make direct object-to-object comparisons. Unlike map methods, they cannot map any number of objects to an external axis.

They simply tell you that the current object is less than, equal to, or greater than the other object that it is being compared to, with respect to the criterion used by the method. An order method is a function with one declared parameter for another object of the same type. The method must be written to return either a negative number, zero, or a positive number.

The return signifies that the object picked out by the SELF parameter is respectively less than, equal to, or greater than the other parameter's object. As with map methods, an order method, if one is defined, is called automatically whenever two objects of that type need to be compared.

Order methods are useful where comparison semantics may be too complex to use a map method. For example, to compare binary objects such as images, you might create an order method to compare the images by their brightness or number of pixels. An object type can declare at most one order method or one map method. Only a type that is not derived from another type can declare an order method; a subtype cannot define one. Example shows an order method that compares locations by building number:.

Example Creating an Order Method. A map method maps object values into scalar values and can order multiple values by their position on the scalar axis. An order method directly compares values for two particular objects.

You can declare a map method or an order method but not both. If you declare a method of either type, you can compare objects in SQL and procedural statements. However, if you declare neither method, you can compare objects only in SQL statements and only for equality or inequality.

Two objects of the same type count as equal only if the values of their corresponding attributes are equal. When sorting or merging a large number of objects, use a map method. One call maps all the objects into scalars, then sorts the scalars. An order method is less efficient because it must be called repeatedly it can compare only two objects at a time.

See "Performance of Object Comparisons". In a type hierarchy, where definitions of specialized types are derived from definitions of more general types, only the root type—the most basic type, from which all other types are derived—can define an order method.

If the root type does not define one, its subtypes cannot define one either. If the root type specifies a map method, any of its subtypes can define a map method that overrides the map method of the root type. But if the root type does not specify a map method, no subtype can specify one either. So if the root type does not specify either a map or an order method, none of the subtypes can specify either a map or order method.

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