SELECT @demoEducba. Oracle PL/SQL DECLARE id NUMBER := 1000; SQL Server T-SQL DECLARE @id integer = 1000; Teradata As we did for UINON example, we can use the same trick for local variables. Have you ever lie on your resume? The syntax for defining one or more variables is: DECLARE [ DEFAULT ] ; The variable name list may contain one or more variable names. You pass in 2019, you get 3 student from prior 4 year since 2015. Using A Variable In MySQL Select Statment In A Where Clause Februari 26, 2023 I would like to know if it's possible to find a value in a select statement and use it in a where clause like: SELECT col1, MAX (col2) - COUNT (DISTINCT col3) as variable FROM table Solution 1: You could try subquery syntax, also called nested select. Following is the syntax of EXECUTE MACRO command. You want to get Productname for a particular ProductID. SET @wishes = 'Hey! Finally, lets look at how to declare an INT variable in SQL Server and assign an inital value. Its best to declare variables when you first use them to ensure that they are always initialized to some valid value and that their intended use is always apparent. Now let us insert some data into this volatile table. SQL Assistant, BTEQ? Notice, the name length is based on your first records. Following is an example of a Macro that accepts parameters. Was Galileo expecting to see so many stars? Consider one example where we will declare one variable named @wishes that wont have any initial value and will have a varchar data type. If one of the SQL statements in Macro fails, then all the statements are rolled back. By the way, I did better than them in school. DECLARE @wishes varchar(100) This is not possible in plain SQL without using PL/SQL construct in Teradata. Promoting, selling, recruiting, coursework and thesis posting is forbidden. How do you declare a variable in Teradata SQL? Formatting is not something stored procedures or SQL is known for. Dynamic SQL enables you to write application code that is reusable because the code defines a process that is independent of the specific SQL statements used. SELECT @wishes AS 'Good Wishes'. DB2 LUW also does not require any variable declaration to pass back to the calling. It would look something like this: If you decide you want to put your logic inside a stored procedure, then you can DECLARE variables. Please let us know here why this post is inappropriate. Tracking Consent PDFs Site Feedback Help Stored Procedures are executed using CALL statement. I updated my answer with an example. Why doesn't the federal government manage Sandia National Laboratories? These dynamic SQL statements are created using Teradata variables. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. This is very common for BI reporting. Teradata stored procedure is created from the following commands: BTEQ utility using the COMPILE command.Following is the syntax of the CREATE PROCEDURE statement. However if you are calling BTEQ code in shell script you can easily use shell variables in BTEQ SQL queries. . You cannot select without an object name when it is placed in union. I have a legacy product that I have to maintain. The following example executes the Macro names Get_Emp; It accepts employee no as parameter and extracts records from employee table for that employee. First let us create a variable table, you can use CTE, but CTE is only valid in one query, so a temp table (in Teradata it was called volatile table) will be a better option if you want to use the variable in multiple queries. They may contain only procedural statements. NUSI may have multiple rows per value. DECLARE @demoEducba1 AS VARCHAR(100)='Happy Learning! How do I create a stored procedure in Teradata? How would that work? How to react to a students panic attack in an oral exam? Why was the nose gear of Concorde located so far aft? Learn SQL on EDUCBA with payal. we will use SELECT @wishes = Hey! In the real word scenario, many application manipulate the date and time data types. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. We can assign the values to the variables declared in SQL with the help of two methods that are given below: 1. ALL RIGHTS RESERVED. We can make the use of the Declare statement to declare the local variables in SQL and then optionally initialize those variables to a certain initial value. The definition of Macros is stored in Data Dictionary. In addition, dynamic SQL lets you execute SQL statements that are not supported in static SQL programs, such as data definition language (DDL) statements. Enjoy unlimited access on 5500+ Hand Picked Quality Video Courses. If you are used to some other database, I will admit that it does seem cumbersome. Assume you have a report in which some queries need to go back 2 year, other queries need to go back 4 year. A while back Teradata moved their documentation to a new web platform (docs.teratadata.com). Date types are highly formatted and very complicated. Can you please explain how doesn't it work? What are two requirements for declaring a variable? Which is correct example for variable declaration? Enjoy unlimited access on 5500+ Hand Picked Quality Video Courses. Does Cast a Spell make you a spellcaster? Users don't need separate privileges on the database objects used inside the Macro. Agree Then use those variables in your statement. Yes and no. Which of the following is used to declare a variable? Good Morning My Friend! What is the difference between macro and stored procedure in Teradata? Use "pre" tags with your current output to preserve spacing and line breaks.. I've seen SMS messages take 24 hours to deliver. Connect and share knowledge within a single location that is structured and easy to search. You can (as one example) declare variables inside of a stored procedure. No from statement needed. Teradata Declare Variable Stored Procedure FOR EACH STATEMENT vs. It will end up with a table containing variable values in each row. I have this code so far: DECLARE @AddressIDS TABLE ( AddressID int ) INSERT INTO Address(Street1, City, StateCode, ZipCode) OUTPUT inserted.AddressID INTO @AddressIDS SELECT S Solution 1: Assuming Street1 + City + StateCode + ZipCode is unique, or that multiple contacts can share the same AddressID, then you don't need to suss out the AddressID . UNION Most of the times, Java wants you to initialize the variable. What if I want to populate column name , database name or tablename as the parameter. CREATE PROCEDURE ( [parameter 1 data type, parameter 2 data type..] ). Some examples of using stored procedures to match complex updates. In simple terms, this means that you can store and process extremely huge data sets using Teradata. Notify me of follow-up comments by email. IN this case you must generate dynamic SQL and use exec. Good Morning My Friend! Variables are very useful when you need to change part of code while keeping most of the code intact. Copyright 1998-2023 engineering.com, Inc. All rights reserved.Unauthorized reproduction or linking forbidden without expressed written permission. If you were a SQL Server user, you knew select union select will do. is something similar possible on TeraData. The declaration of a variable generally takes the following syntax: dataType variableName ; dataType variableName ; Where dataType is a type-specifier which is any Java data type and variableName is the unique name of a variable. SQL commands stored in Teradata variables can be executed using. This article is about detailed descriptions and examples of the commonly used Teradata date functions that you can use to manipulate date columns in the Teradata, stored procedure or in embedded SQLs. Registration on or use of this site constitutes acceptance of our Privacy Policy. Many DBMS have drop table if exists tablename, unfortunately, you have no such luxury in Teradata. This is a nice solution because it will work on any RDBMS that supports CTEs (so everything except for mysql --UPDATED-- mysql 8.0+ now supports CTEs!). I have a problem where I need to parse a bunch of XML files into a SQL database where the needed elements are all in different branches of the XML file. How does Teradata solve the similar situation? Variables in SQL procedures are defined by using the DECLARE statement. Within a Macro, these parameters are referenced with ; (semicolon). What capacitance values do you recommend for decoupling capacitors in battery-powered circuits? The Current_Date part can be replaced with any scalar query. WITH dummy(num) AS ( SELECT 1 AS num) SELECT CURRENT_TIMESTAMP AS mytime FROM dummy UNION SELECT CURRENT_TIMESTAMP + CAST('10-01' AS INTERVAL YEAR(2) TO MONTH) FROM dummy; In Teradata, you can only define local variables in macros, procedures and functions. And their documentation is not as good as others. In Case statement, we defined conditions. It is a pain. In SQL Server or Oracle you can define it very easily. Very often when working with BTEQ script you will face requirement to use dynamic variables or parameters. Convert arbitrary date-like string to date in Teradata, Getting the Libname from the Teradata Schema, How to remove null date data in Teradata 16.20, Group by grouping sets in BigQuery vs Teradata, Am I being scammed after paying almost $10,000 to a tree company not being able to withdraw my profit without paying a fee. It turned out in Teradata you will need to create a temp variable table, then cross join that to the table/tables which you want to use variables. SELECT CURRENT_TIMESTAMP + CAST('10-01' AS INTERVAL YEAR(2) TO MONTH); Executed as Single statement. CREATE MACRO Get_Emp_Salary(EmployeeNo INTEGER) AS ( SELECT EmployeeNo, NetPay FROM Salary WHERE EmployeeNo = :EmployeeNo; ); Executing Parameterized Macros 2016-2018. Let's quickly see an example to understand this. By joining you are opting in to receive e-mail. Initializing simply means assigning a beginning (initial) value to a variable. Why must a product of symmetric random variables be symmetric? Teradata does not offer variables in the same manner as SQL Server. By using this website, you agree with our Cookies Policy. The law states that we can store cookies on your device if they are strictly necessary for the operation of this site. In this post we will see different methods in which you can pass parameters to BTEQ script. Asking for help, clarification, or responding to other answers. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. See the example below. You cannot declare variables in a typical SQL Statement that you are running directly from your code editor. You can change it to the database you are using. If you dont include this, the 2nd time you run the stored proc, it will complain so and so table exists. SQL data types, SQLLEN values, and SQLTYPE values that the precompiler uses for host variables in COBOL programs. What capacitance values do you recommend for decoupling capacitors in battery-powered circuits? Macros are created using CREATE MACRO statement. So I can create a shell script and pass the values as parameter. Oftentimes, we cannot change the world, we will adapt ourselves to interact with the world. Specifying the initial value to the variable is the optional thing. Teradata Dynamic SQL Statements Sometimes it is required to create SQL statements (DDLs, DMLs etc) dynamically as per some logic/data that is not known earlier. How can I recognize one? Row 3-11, create a variable table, which I will use later. looks the variable table method works. This site uses different types of cookies. 2- Click Ctrl + Shitt + Mouse right button and select "Open Command Window here" (This is to open the command promt, you can also open the command promt and type the command: cd C:\Program Files (x86)\Android\android-sdk\platform-tools) 3- Once the shell is open, type this commands in SQL Assistant, for BTEQ you can use shell scripts to plug a variable in. SELECT concat(@demoEducba1,@demoEducba2). Teradata Macros can accept parameters. In the code below, I'm looking to declare a variable and use it in a WHERE statement.. Its so important to do this that Java either initializes a variable for you, or it indicates an error has occurred, telling you to initialize a variable. Has Microsoft lowered its Windows 11 eligibility criteria? Affordable solution to train a team and make them project ready. In Basic, a string variable ends in a $, and whole number variables, known as integers, end with a %. As always, code is included here if you want to follow along. Save my name, email, and website in this browser for the next time I comment. Following is the generic syntax of the CALL statement. This website uses cookies to improve your experience. Only 1 row, so if you cross join it with other tables, it will add the variable columns to the table without causing dup. Teradata - Stored Procedure Previous Page Next Page A stored procedure contains a set of SQL statements and procedural statements. If you find difficulty to write other queries in Teradata, feel free to raise it here in the comment area. For example, the following SQL will encounter one error: SELECT CURRENT_TIMESTAMP AS mytime DECLARE @demoEducba AS VARCHAR(100)='Happy Learning!' The following example creates a Macro called Get_Emp. The following example calls the stored procedure InsertSalary and inserts records to Salary Table. Login. You can see the results. Is lock-free synchronization always superior to synchronization using locks? A user that is handed the script only needs to change things at the very top (in the CTE declaration) instead of hunting through the sql to find. Agree Java uses the keyword int for integer, double for a floating point number (a double precision number), and boolean for a Boolean value (true or false). Is it possible to just use the following syntax on Teradata? Cookies are small text files that can be used by websites to make a user's experience more efficient. It just isn't valid syntax in a vanilla SQL Assistant script. Projective representations of the Lorentz group can't occur in QFT! Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. These dynamic SQL statements are created using Teradata variables. Note that when we do not specify the initial value to the variable, the variables value is by default assigned to NULL. Literals, expressions, the result of a query, and special register values can be assigned to variables. You need EXEC privilege to execute the Macros. Sorry, Hillary. We can assign the values to the variables using the SET statement with the help of the following syntax. Provides better security since the data is accessed through stored procedures instead of accessing them directly. Already a Member? I wrote a create table statement. Clash between mismath's \C and babel with russian. Further, the declared variables are referred to as the local variables. If a law is new but its interpretation is vague, can the courts directly ask the drafters the intent and official interpretation of their law? Find centralized, trusted content and collaborate around the technologies you use most. Letting Excel VBA know you are using a variable is called declaring a variable. The definition of stored procedure is stored in database and the parameters are stored in data dictionary tables. The website cannot function properly without these cookies. Once a condition is satisfied, its corresponding value is returned. For example: int age; float weight; char gender; In these examples, age, weight and gender are variables which are declared as integer data type, floating data type and character data type respectively. Normally a SELECT results in rows being returned to the user. You may also have a look at the following articles to learn more . Are there conventions to indicate a new item in a list? Use DECIMAL ( i + d, d) or NUMERIC ( i + d, d) No exact equivalent. For example: DECLARE @site_value INT = 10; This variable declaration example would declare a variable called @site_value that is an INT datatype. The SELECT statement can be used to assign the values to the variables in SQL as well as retrieving the value of those variables. Remember, however, that the outer stored procedure (and each inner stored procedure) is still unable to return more than one value to its caller. By Raj Teradata The easiest method to pass parameters to BTEQ script is to call it within a shell script. To declare (create) a variable, you will specify the type, leave at least one space, then the name for the variable and end the line with a semicolon ( ; ). The term stored procedure refers to a stored procedure you write with SQL statements. The open-source game engine youve been waiting for: Godot (Ep. As we did for UINON example, we can use the same trick for local variables. In TSql I can define a variable like so: DECLARE @Threshold AS int; SET @Threshold = 5; I can then use it like so: ,COALESCE ( CASE WHEN X >= @Threshold THEN A ELSE NULL END ,CASE WHEN Y >= @Threshold THEN B ELSE NULL END ) AS Bla is something similar possible on TeraData tsql teradata Share Improve this question Follow Gives better maintenance since the business logic is tested and stored in the server. Read More, In case of sale of your personal information, you may opt out by using the link Do Not Sell My Personal Information. But there are parameters for macros, and if it's a script, you can use shell-variables in Unix. Following is an example of a Macro that accepts parameters. The intention is to display ads that are relevant and engaging for the individual user and thereby more valuable for publishers and third party advertisers. DATE is the datatype used for storing date values in a table. Comments has been added for each step in the procedure to provide explanation of that particular step. TPT (Teradata Parallel Transporter) is a client suit that support multiple instances of . I created a fake student table containing 4 records with various enrollment dates. You can use ? Row 78-96, I copied the previous script to stored proc. Row 1, use default database, here I block database name to protect privacy. Teradata is a parallel 'shared-nothing' database management system. Definition. Can we write stored procedure in Teradata? What's wrong with my argument? SQL commands stored in Teradata variables can be executed using EXECUTE IMMEDIATE command. CREATE PROCEDURE ( [parameter 1 data type, parameter 2 data type..] BEGIN. In the where clause, I limited enrollment date between prior2yearbegin and targetyearend, i.e. Following is the generic syntax of the CREATE PROCEDURE statement. By signing up, you agree to our Terms of Use and Privacy Policy. The following example executes the Macro names Get_Emp; When the following command is executed, it retrieves all records from employee table. Asking for help, clarification, or responding to other answers. rev2023.3.1.43269. Let's look at the example below: In the above script I have created 4 variables with column names, database name, tablename and using it directly in the BTEQ query. Good Morning My Friend! , 29 , , ( SSIS Variable). No exact equivalent. You can call the stored procedure and then call the RESULT_SCAN function and pass it the statement ID generated for the stored procedure. The teradata in touch with time when fired on a stored procedure codes. To learn more, see our tips on writing great answers. I select the table outside the procedure. Declaring a Transact-SQL Variable The DECLARE statement initializes a Transact-SQL variable by: Assigning a name. The values of those variables can be changed and reassigned using various ways, such as using the SET statement or using the SELECT query statement. Here, we declare a variable called @LastName as an input parameter and three Output parameters. This page summarize the equivalents in Teradata SQL. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Your email address will not be published. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Close this window and log in. I consent to the use of following cookies: Necessary cookies help make a website usable by enabling basic functions like page navigation and access to secure areas of the website. Learn SQL on EDUCBA with payal.' Row 64, create a procedure getlast4yearstudent and pass target year variable year_var. Within a Macro, these parameters are referenced with ; (semicolon). How can the mass of an unstable composite particle become complex? Why do you need to initialize a variable? What does a search warrant actually look like? Publish articles via Kontext Column. We will declare one variable named @demoEducba, declare the data type of that variable to the varchar, initialize the variable with a certain value, say Happy Learning! and then fetch the variables value using the select statement as shown below. I have below BTEQ script: Now you can see I have hardcoded SQL query in the BTEQ. Macro is a set of SQL statements which are stored and executed by calling the Macro name. Already a member? Teradata SQL Tricks for SQL Server/Oracle Developers. Launching the CI/CD and R Collectives and community editing features for Teradata declaring dates at start of the script, Teradata Sql assistant not running SELECT statements, check if volatile table exists in teradata, Select a variable to output from within stored procedure in Teradata. It's free. However, you can use single-row-single-column volatile tables in an equivalent manner. Variable declarations in a Teradata Stored Procedure are always local to the surrounding compound statement (BEGINEND) and to all the compound statements located within the surrounding BEGINEND. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. We declare an integer variable x in the outer and inner compound statements. SELECT @wishes = 'Hey! Using the SET statement. In your code editor window, you would be more likely to create a volatile table and use it to store the value of your "variable". Single statement are referenced with ; ( semicolon ) website can not select without an object when... Sql data types, SQLLEN values, and SQLTYPE values that the uses. How do you recommend for decoupling capacitors in battery-powered circuits to some other database, I copied the Previous to... Specifying the initial value to a variable in SQL Server and assign an inital value and with. For storing date values in a table containing 4 records with various enrollment dates script you... Picked Quality Video Courses coworkers, Reach developers & technologists share private knowledge with coworkers, developers. Procedure you write with SQL statements in Macro fails, then all the statements are using. So far aft client suit that support multiple instances of variables declared in SQL well. First records stored procedure InsertSalary and inserts records to Salary table look at the following command executed... The statement ID generated for the operation of this site constitutes acceptance of our Privacy Policy script... To other answers been added for each step in the Where clause, teradata declare variable will use later calls stored. Make a user 's experience more efficient executed, it will end up a. Inner compound statements ( initial ) value to a stored procedure Previous Page next Page a procedure! Forbidden without expressed written permission syntax on Teradata SQL is known for well as the! Values that the precompiler uses for host variables in SQL Server or responding to other.., use default database, I limited enrollment date between prior2yearbegin and targetyearend,.. Hand Picked Quality Video Courses back 4 year, other queries need to go back year! Example, we will adapt ourselves to interact with the world the calling, coursework and thesis is. Replaced with any scalar query variables declared in SQL as well as retrieving the value those... An input parameter and extracts records from employee table Output parameters records with various enrollment dates command. Initializes a Transact-SQL variable the declare statement initializes a Transact-SQL variable by: assigning beginning! That can be used by websites to make a user 's experience more efficient of. Table containing 4 records with various enrollment dates called declaring a Transact-SQL variable by: assigning a (... Responding to other answers need to go back 2 year, other queries need to change part of while... And website in this post is inappropriate Exchange Inc ; user contributions licensed under CC.... Sql statement that you are using a variable table, which I will later! Easy to search inserts records to Salary table select union select will do legacy product I... Dynamic SQL and use exec the way, I limited enrollment date between prior2yearbegin targetyearend. The next time I comment and executed by calling the Macro names Get_Emp ; it employee... Application manipulate the date and time data types inside the Macro name what is the used! What if I want to follow along Macros is stored in database and parameters! Agree to our terms of service, Privacy Policy you use most time I comment to... The comment area each step in the Where clause, I did better than them in.! ) this is not something stored procedures are defined by using the set statement with world... That you can easily use shell variables in COBOL programs outer and compound... Other answers rolled back have drop table if exists tablename, unfortunately, you to... Our terms of use and Privacy Policy SQLLEN values, and special register values can be used to other! Have below BTEQ script it to the variables using the select statement as shown below literals expressions! Cookie Policy, and special register values can be used by websites to make user... Picked Quality Video Courses data Dictionary tables you can call the stored procedure in Teradata variables are executed.! Is to call it within a shell script and pass target year variable year_var many... Are referred to as the parameter Quality Video Courses retrieves all records from employee table for that employee at! A Macro, these parameters are stored in Teradata not declare variables inside of a Macro these! 2023 Stack Exchange Inc ; user contributions licensed under CC BY-SA notice the! Get_Emp ; it accepts employee no as parameter that the precompiler uses for host variables in a typical SQL that. Each step in the real word scenario, many application manipulate the date and time data.... Are strictly necessary for the stored proc a team and make them project ready can easily use variables. You are calling BTEQ code in shell script and pass target year variable year_var the select statement can assigned... Make a user 's experience more efficient follow along without expressed written permission dynamic SQL statements and procedural.... 2Nd time you run the stored procedure Previous Page next Page a stored procedure codes why does n't the government... Set statement with the help of two methods that are given below: 1 any query... Without expressed written permission Page a stored procedure Previous Page next Page a stored you. With the world, we will adapt ourselves to interact with the help of two methods that given... An example of a stored procedure in Teradata, feel free to raise it here in the area... This case you must generate dynamic SQL statements are created using Teradata variables can be to... Stored procedure and then call the RESULT_SCAN function and pass target year year_var. Called @ LastName as an input parameter and three Output parameters my name email., SQLLEN values, and special register values can be replaced with any scalar query outer inner. Procedure statement n't the federal government manage Sandia National Laboratories variable called @ as... Of those variables since the data is accessed through stored procedures are using! Acceptance of our Privacy Policy script, you knew select union select will do back. From your code editor get 3 student from prior 4 year shell-variables in Unix well as retrieving the value those! First records PL/SQL construct in Teradata, feel free to raise it here in the same manner as Server! Uinon example, we will adapt ourselves to interact with the help of call. Code editor I block database name or tablename as the parameter initial value to variable! And share knowledge within a single location that is structured and easy search. ; it accepts employee no as parameter or Oracle you can use shell-variables in Unix offer variables the! As single statement Server user, you agree to our terms of and! From employee table are created using Teradata is forbidden as SQL Server to match complex updates, email, SQLTYPE... Methods that are given below: 1 column name, database name or as. My name, database name to protect Privacy Raj Teradata the easiest method to pass back to the is! Sqllen values, and if it & # x27 ; shared-nothing & # ;... Is based on your device if they are strictly necessary for the operation of this.... Enrollment date between prior2yearbegin and targetyearend, i.e see I have a legacy product that I have a report which! Concorde located so far aft it the statement ID generated for the next time I comment value to variable. Cookie Policy agree to our terms of use and Privacy Policy and cookie Policy script! You agree to our terms of service, Privacy Policy code intact variables declared in SQL with help! Since the data is accessed through stored procedures to match complex updates to understand this vanilla Assistant... Commands stored in database and the parameters are stored in data Dictionary Lorentz group ca occur... An INT variable in SQL with the world, we declare an variable... Created from the following articles to learn more integer variable x in the area! Use and Privacy Policy and cookie Policy you want to get Productname for a particular ProductID it is placed union. Row 78-96, I did better than them in school a stored procedure is created from the following articles learn! Clash between mismath 's \C and babel with russian accepts employee no as parameter and three Output parameters scenario... To get Productname for a particular ProductID generate dynamic SQL and use exec for. Single location that is structured and easy to search that you are calling code. Very useful when you need to go back 2 year, other queries need to go back 4 year 2015! Is placed in union on the database you are using a variable here I block database name to protect.. Condition is satisfied, its corresponding value is returned optional thing browse questions... A students panic attack in an oral exam open-source game engine youve been waiting for: Godot (.! Single statement to assign the values to the calling be replaced with scalar. How does n't it work CURRENT_TIMESTAMP + CAST ( '10-01 ' as INTERVAL year ( 2 ) to ). Oracle you can call the stored proc, it will complain so so! Further, the result of a Macro, these parameters are referenced with ; ( semicolon ) and compound! Vanilla SQL Assistant script we did for UINON example, we can store and extremely... I block database name or tablename as the parameter without using PL/SQL construct in Teradata SQL used for storing values. A string variable ends in a list date between prior2yearbegin and targetyearend,.! At how to declare a variable clicking post your Answer, you agree with our Policy. Populate column name, database name to protect Privacy with russian teradata declare variable known... Dbms have drop table if exists tablename, unfortunately, you get 3 student from prior 4 year since..