What Is Data Manipulation Language?

At present, the programming languages used must indicate the operations that the CPU will process, and omitting such descriptions only indicates the required results. The process of obtaining the results is not a programming language completed by the computer itself as a processing language. ^[1]

The function of "data processing language" is to complete adding data, modifying data, and deleting data. These functions and the "database query language" to be described later are the most commonly used operation commands in database applications, and the two parts often work together.

The following are commonly used DML commands:

INSERT:

UPDATE;

DELETE.

(1) Add data

After creating the data table, use the INSERT command to add new data to the table. You can simply add records one by one, or you can add records in one data table to another data table in batches in combination with the SELECT command to be described later. Note that the INSERT command is used to add a new record to the data table, rather than adding a field. If you do not specify a field value, the database will automatically add a default value or empty, as long as this field is specified when the data table is created or allowed to be empty.

(2) Modify the data

Data modification is one of the most common operations in database operations. Use the UPDATE command to change the content of some fields in a record. The UPDATE command is usually used with the WHERE clause. The purpose of this clause is to limit the modification of the data in those rows in the specified range. If you do not use the WHERE clause in the UPDATE command, then all record rows in the data table will be modified.

(3) Delete data

use

Symbol processing language (symbol processing language) is a computer language designed to express and process complex concepts. Such as LISP and PRO-LOG languages ^[3]

In data processing, users can use various programming languages in order to express various requirements for data processing and write various processing programs. This is also similar in knowledge processing. In order to express knowledge, express the intention of using knowledge, and describe the process of knowledge processing, it needs the support of various knowledge processing languages.

Knowledge processing languages can be classified into two categories: procedural and descriptive. The descriptive processing language only requires the user to describe "what to do", while the question "how to do it" is spoiled automatically by the processor in the machine. Procedural processing languages not only require users to describe what they do, but they also need to specify what they do.

Because the processing of knowledge sometimes includes a lot of data processing, but mainly the processing of symbols and logical reasoning. Therefore, some programming languages for data processing are used, such as FORTRAN, COBOI. It is inconvenient or impossible at all to solve the problem of knowledge processing, both in terms of the structure description of the processed object and in various operations that can be performed on the processed object. Therefore, people have been searching for a programming language suitable for solving artificial intelligence problems since the early days of artificial intelligence research. Among them, Lisp was a pioneer, and it has developed a lot later. In addition, Prolog, Smalltalk, OPS, and FRL are several general-purpose programming languages that have great influence in the field of artificial intelligence. These languages play a very important role in the field of knowledge processing and in many specific knowledge-based systems. Because the design of these knowledge processing languages is always associated with a certain knowledge representation mode and knowledge processing mode, they each have their own unique knowledge representation mode and knowledge processing mode. ^[5]

The IETF's IPTEL working group described the framework and implementation requirements of the Call Processing Language (CPL) in RFC2824, followed by draft-ietf-iptel-cpl 06. The details of the CPL language are defined in txt. Users can write script files through the CPL and upload them to the Signaling Server. During the process of a user initiating or receiving a call, the signaling server dynamically provides the user with services such as call forwarding and call forwarding on busy based on the results of running the CPL script file.

The network model that the CPL script runs in consists of two parts: the end system and the signaling server. End systems refer to devices that initiate and receive signaling information and media streams, including telephone equipment, PC telephone clients, and automatic voice systems. A signaling server is a device that relays and controls signaling information. In the network constructed by the SIP protocol, it refers to a proxy server, a redirect server, and a registration server. ^[6]