What is the full form of TCL(i) TCL: Transaction Control LanguageTCL stands for transaction control language. TCL commands mainly help manage and regulate database transactions to preserve consistency. The statements can be organized into logical transactions using TCL. During the process, the term "transaction" refers to a group of SQL statements executed on the knowledge and information kept in the Database Management System (DBMS). Any transaction made momentarily takes place in the database (database). A user must issue TCL commands to make these modifications/changes permanent. The DDL command and DML command also let a user manage some modifications to the data in a table that are made by DML statements. TCL CommandsThere are typically three main types of TCL commands. They are as follows:
1. COMMIT: This command enables users to preserve a certain database transaction permanently. The changes produced when using a DML command like DELETE, UPDATE, or INSERT are temporary until the current session is closed. In other words, the changes could only be done if one permanently stores data. Therefore, we use the COMMIT command to keep away from it and be safe. It designates these adjustments as lasting. The COMMIT command has the following syntax: COMMIT; 2. ROLLBACK: The purpose of this command is to return the database to its very committed state. If you want to jump to a save point in an ongoing transaction, use it with the SAVEPOINT command. In essence, it assists a user in retrieving or recovering data to the most recently committed state save-point. An UPDATE command may be used by a user to make a few minor updates to the database, but after doing so, the user may discover that the changes are not necessary. Therefore, the user can use the ROLLBACK command to roll back the data to the most recently committed state or any specific save-point if the inserted, updated, or deleted data is wrong or undesired. In other words, you can undo the modifications if the user didn't utilize the COMMIT command. The ROLLBACK command has the following syntax: ROLLBACK TO savepoint_name; 3. SAVEPOINT: With this command, a transaction can be saved momentarily to roll back to that point, if necessary, quickly. Besides, you may use the SAVEPOINT command to identify multiple data states in a table and utilize the ROLLBACK command to roll back to any of them as needed. The SAVEPOINT command has the following syntax: SAVEPOINT savepoint_name; Advantages of the TCL
Disadvantages of TCL
(ii) TCL: Tool Command LanguageTCL stands for tool command language. TCL, which is pronounced "tickle" and written Tcl rather than TCL, is the perfect option if you're searching for a dynamic programming language that's simple to learn. Everything from desktop and web applications to network management and testing may be done with it. Tcl is an established but still-emerging language that is open source, useful for businesses, and very extensible. In the industry, Tcl is preferred as a scripting language. The Tcl language supports control structures, variables, network socket access, and APIs. You may work on a variety of platforms with Tcl. This dynamic programming language is high-level, all-purpose, and interpretable. The shell software Tcl reads the Tcl command from a file or its standard input and outputs the necessary information. This scripting language uses strings and procedural syntax. John Osterhout developed the concept of this language in 1989. This language makes it simple to embed Inti () apps. Every command in the language has a predefined function. These commands are the language's reserved phrases and the vocabulary and cannot identify other variables. However, you can create versions of any of these instructions using these Tcl commands to replace the built-in functions. The interpreter can work faster and more efficiently using Tcl commands to ensure precise input and performance. Tcl command syntax: Name of command arg 1 arg 2… argN It is typically a list of words, in which the first word represents the command to be first executed. The next words are more like a summary of the points. In Tcl, one can use " " or {} to combine multiple words to create a single argument. TCL Data TypesThe only kinds of data that Tcl supports are strings. In Tcl, everything that we need to represent is done using Strings, be it the commands, arguments, output, and variables. Similarly, numerical parameters and outcomes are also provided as strings in the commands that require them. Many commands specify a format for their string parameters, but they select how to interpret this. For instance, Tcl command strings are frequently used as parameters and can be executed as part of the instructions. Remembering that everything in the Tcl interpreter is a string function is helpful when learning it. In many aspects, Tcl constructs are similar to more sophisticated constructs in other languages. The Tcl constructions, in comparison, are not organized in any way; they are merely strings of letters, which causes them to behave differently from the structures they would initially appear to be. Ultimately, Tcl strings can be thought of as commands, expressions, or even lists, depending on how they are translated. Next TopicUAE |