sql case statement with nested select sql case statement with nested select

SELECT Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. how to get the distinct records based on maximum date? I know to use case when condition then X else y end but how do you do a nested one in the same fashion for each record in a record set. The following example uses the CASE expression to change the display of product line categories to make them more understandable. The result gets evaluate for the TRUE/FALSE condition for each WHEN Statement. THEN DEP Your email address will not be published. Calculating probabilities from d6 dice pool (Degenesis rules for botches and triggers). Why is this sentence from The Great Gatsby grammatical? Simple Case support only equality check. This example performs the same check as the other examples but uses the searched case method. You can probably write two CASE statements to display it: Else contain Nested CASE Statement in SQL inside it. The HAVING clause restricts the titles to those that are held by salaried employees with a maximum pay rate greater than 40 dollars, or non-salaried employees with a maximum pay rate greater than 15 dollars. INNER JOIN A001470.CUENTAFACTURACION CF Below is a selection from the "OrderDetails" table in the Northwind sample database: The following SQL goes through conditions and returns a value when the first condition is met: The following SQL will order the customers by City. Evaluates a list of conditions and returns one of multiple possible result expressions. from idm.OPTUS_JOINED_VIEW_V_3_6 WHEN Canada THEN North America ; Ben, That is exactly what I needed to know! Why is this sentence from The Great Gatsby grammatical? The simple CASE expression compares an expression to a set of simple expressions to determine the result. WHEN MILITARY_STATUSES (AMAR,DODMA,FAMMA,RMAR,VMAR) Time arrow with "current position" evolving with overlay number. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Hi Ben! Within a SELECT statement, the CASE expression allows for values to be replaced in the result set based on comparison values. The following example uses the CASE expression in an UPDATE statement to determine the value that is set for the column VacationHours for employees with SalariedFlag set to 0. But Im pretty sure I am only giving one value per WHEN/THEN statement. I need to use case statement like below written ,Can someone help me in this ? It doesnt make several steps on different variables to get the result you want. The CASE statement is SQL's way of handling if/then logic. A case expression allows the user to use IF - THEN - ELSE logic without using procedures in SQL statements. Can you please clarify what determines that? WHEN MILITARY_STATUSES (AANG,DODAG,FAMAG,VANG) dl_month, I.e. We use the following format to write Case statement logic in SQL queries. Nested query inside of Case statement I'm trying to define my WHEN statements by pulling a value from another table using a nested select top 1 statement, and if the value selected is not null then give me my original select, if it is null and another value from the same table is not null then give me 'hard value' else 'other hard value'. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Only one condition can be true. SELECT ITEM ,DETAIL_LEVEL_DESC AS DESCRIPTION ,COMP_DETAIL_ID AS PROMO_ID ,CASE WHEN CHANGE_TYPE = 'N' THEN CASE WHEN INSTR (UPPER (DETAIL_LEVEL_DESC), 'S/P')!=0 THEN 'SPP' Hi Margaret, No problem Margaret, it was a good challenge for me! SUM(count_hist) AS count_hist Azure SQL Managed Instance Azure Synapse Analytics What video game is Charlie playing in Poker Face S01E07? I'm sure it's probably pretty simple but can't see what's wrong. The value used in the ELSE statement is what is returned if no match is found. Aggregate expressions that appear in WHEN arguments to a CASE expression are evaluated first, then provided to the CASE expression. Mostly used when we use CASE in the select clause. This happens for both Simple and Searched expressions. operators ( AND, OR ). User-864238592 posted. FROM ( THEN NG The CASE statementallows you to perform an IF-THEN-ELSE check within an SQL statement. The CASE statement should let you do whatever you need with your conditions. AND PERMIL_STATUSES.POS=1 It offers multiple hands-on interactive SQL courses with exercises to cover nested SELECT statements and other challenging SQL features. SELECT first_name, last_name, country, Boolean_expression is any valid Boolean expression. select d.seq, Scan Map Layer Type, Avg from Statement(s) could not be prepared. Ive updated it here. WHEN current_page_url %optus.com.au/shop/broadband/mobile-broadband% THEN Fixed_MBB Not the answer you're looking for? The expressions are used within each condition without mentioning it at the start of the CASE statement. Ill be writing about how to write the IF statement in SQL. current_page_url ilike %optus.com.au/shop/home-phone% OR With Boolean_Expression_N, Search Case support any operation which results in a Boolean value. Yes. and our SUM(count_topo) AS count_topo, It checks the number of employees and determines if they have an odd or even number of employees. SELECT x Find centralized, trusted content and collaborate around the technologies you use most. If you dont want all columns and only want the results of the two CASE statements, then you can remove the *. The expression evaluated when the simple CASE format is used. Optimize SQL Queries with CASE Expressions in Unexpected Ways | by Boris J | Towards Data Science Write Sign up Sign In 500 Apologies, but something went wrong on our end. LearnSQL.com allows you to choose from a full learning track, mini-tracks to sharpen targeted skills, and individual courses. Is it a bug? ON PA.IDCUENTAFACTURACION = CF.IDCUENTAFACTURACION Hopefully, that explains how the SQL CASE statement is used and answers any questions you had. Syntax. Select * means select all columns, but then you have a CASE statement. WHEN MILITARY_STATUSES (AAIR,DODAF,FAMAF,RAIR,VAIR) The CASE expression goes through conditions and returns a value when the first condition is Azure SQL Database Again, in real life, we perform different actions depending upon the outcome of different conditions. THEN In SQL, IF statements in SELECT statements can be done with either of these methods. ) when ued.user_type in (85,73,74) then t2.amt_type in (TXN_AMT,COMM) else t2.amt_type =TXN_AMT end case, Write a query to display EMPLOYEES having ID 101,102,103 as per the Ive had a look at your query and yes I think it can be improved with CASE. rev2023.3.3.43278. Margaret. The expression is stated at the beginning, and the possible results are checked in the condition parameters. More examples of Nested Subqueries. Due to its name, this expression is regularly mistaken for the CASE statement available in some other languages. It's good for displaying a value in the SELECT query based on logic that you have defined. Statements that include a subquery usually take one of these forms: WHERE expression [NOT] IN (subquery) WHERE expression comparison_operator [ANY | ALL] (subquery) WHERE [NOT] EXISTS (subquery) Check for more subquery rules and subquery 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. If Flight_Ticket < $400 then inner CASE will execute. Does a barbarian benefit from the fast movement ability while wearing medium armor? so i want sal which has greater than avg(sal) ,if sal >avg(sal) then give flag Y other wise N? >ANY(100,200,300), the ANY operator will fetch all the values greater than 100. e.g. Depending upon Flight ticket value, one amongst the following result will be displayed: We can use CASE with UPDATE. Query 2: SIMPLE CASE with the ELSE option. select d.seq, Historical Layer Type, Avg from )CASE exits when first value/expresion is TRUE, and sometimes it goes through all values/expresions?! Making statements based on opinion; back them up with references or personal experience. As the data for columns can vary from row to row, using a CASE SQL expression can help make your data more readable and useful to the user or to the application. Its SQL Server only. WHEN MILITARY_STATUSES = DODAF, DODAG,DODAR,DODCG,DODMA,DODNA,DODNG from GRAPHICS_DOWNLOAD g where itcl_id This occurs prior to evaluating the CASE expression. when last_chg='2009001' then . Could you test that the values in NUMEROTELEFONO are actually NULL? CASE statements themselves are not new; they have long been implemented in other programming languages. FROM customers Thanks for contributing an answer to Stack Overflow! : WHEN MILITARY_STATUSES = AAIR,AANG,AARMY,ACG,AMAR,ANAVY,ANG By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Hi Ben, A simple example: ic.product_theme THEN M WHEN Value_1 THEN Statement_1 EXISTS The EXISTS keyword produces a Boolean value [TRUE/FALSE]. WHERE PER_MILITARY_ID=MILITARY_ASSOC.ID So thanks for that one also. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Does a summoned creature play immediately after being summoned by a ready action? A subquery can be nested inside other subqueries. SELECT CASE Expression. (CASE WHEN (( current_page_url ilike %optus.com.au/shop/broadband% OR current_page_url ilike %optus.com.au/shop/deals-bundles% OR The output for that column should be essentially, if W1 Status = Not Trial+ and Status Now = Trial+ THEN 'Increased . AND cs.name LIKE %||:P835_STATE||% If ELSE is not present and Case_Expression matches with none of the values, then. The Boolean expression evaluated when using the searched CASE format. : SQL Server Case Statement. Result: Below diagram explains the execution flow of the SEARCHED CASE with NO ELSE. Lets learn how to use Case in SQL and its concept in the following sections. The MySQL CASE Statement. optN: An expression that has a least common type with expr and all other optN. Introduction, History, Types, Versions, SQL Server CREATE, ALTER, DROP Table [T-SQL Examples], How to Create Login, User and Grant Permissions in SQL Server, SQL Server Tutorial PDF for Beginners (Free Download). This is case statement within the case statement. Acidity of alcohols and basicity of amines. Boris J 100 Followers Boris ( borisj.com) is a Data Engineer . E.g. We can use a Case statement in select queries along with Where, Order By, and Group By clause. T-SQL CASE Clause: How to specify WHEN NULL, OR is not supported with CASE Statement in SQL Server, TSQL CASE with if comparison in SELECT statement. It should have the same result, but its a bit cleaner and has less code. Blocks can be nested - i.e., because a block is an executable statement, it can appear in another block wherever an executable statement is allowed. ELSE Result. This means that each expression in the WHEN section is evaluated individually. whether CASE_Expression = VALUE_1, VALUE_2. (select ic.id from item_class_data ic Thanks for the comment. (select ic.id from item_class_data ic To learn more, see our tips on writing great answers. When subtracting 10 hours from VacationHours results in a negative value, VacationHours is increased by 40 hours; otherwise, VacationHours is increased by 20 hours. = THEN DOD http://msdn.microsoft.com/en-us/library/ms181765.aspx, How Intuit democratizes AI development across teams through reusability. where ic.product_type in (Graphics) and ic.product_theme=Hist) So, once a condition is true, it will stop So, how can you have an SQL IF statement? INNER JOIN A001470.INDIVIDUO I ON ICF.IDINDIVIDUO = I.IDINDIVIDUO See those and add your comments. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. E.g. It returns a corresponding value associated with the condition defined by the user. Evaluates, in the order specified, Boolean_expression for each WHEN clause. Very Informative. Analytics Platform System (PDW). (AVG(NULLIF(count_scan_map, 0))) AS avg_scanmap, Select C_ID from COURSE where C_NAME = 'DSA' or C_NAME = 'DBMS'. Result: Below diagram explains the execution flow of a SIMPLE CASE with ELSE. I'm having trouble getting a CASE statement to work in a nested select. sql statement, Incorrect syntax near update Select Case @location When 'MediaFiles' Then update tblMediaFiles set mdActive=1 When 'MediaFiles1' Then. condN: A BOOLEAN expression. The simple CASE expression operates by comparing the first expression to the expression in each WHEN clause for equivalency. when_expression is any valid expression. rev2023.3.3.43278. Are you looking to select all columns from permil_statuses, as well as the result of the CASE statements? Your select's are also exactly the same, so there isn't really a need for a case unless of course you intend for them to be different. Thanks for contributing an answer to Stack Overflow! It is great because It is what I am looking for. SUM(count_scan_map) AS count_scan_map, We can write this code using SQL IIF statement syntax as following. So, once a condition is true, it will stop reading and return the result. ) sub As an example, say we had a table with 2 integer fields, column a and column b. We can nest CASE statements similar to nested ifs that we find in most programming languages. A limit involving the quotient of two sums. Within a SELECT statement, a simple CASE expression allows for only an equality check; no other comparisons are made. else_result_expression is any valid expression. The SQL CASE statement allows you to perform IF-THEN-ELSE functionality within an SQL statement. You have IF, ELSE, ELSIF and END. 102 (Hint: Union Operator / Case Statement). To elaborate more, consider below example: Lets consider categorizing Condition and Action separately from the above example below: In the above example, we can see that the outcome of the different conditions is governing separate action. However, thats when youre working with PL/SQL. Why are non-Western countries siding with China in the UN? I know to use case when condition then X else y end but how do you do a nested one in the same fashion for each record in a record set. There are two types of CASE expressions: simple and searched. WHEN MILITARY_STATUSES = FAMAF,FAMAG,FAMAR,FAMCG,FAMMA,FAMNA,FAMNG Is it suspicious or odd to stand by the gate of a GA airport watching the planes? ELSE NUMEROTELEFONO I guess my understanding of SQL is wrong, because I would have thought this would return the same thing as. CASE NUMEROTELEFONO If these expressions are equivalent, the expression in the THEN clause will be returned. The. Is there a possibility to format the column alias? Then we can use ORDER BY to have the column in the order we prefer, with the number of students that passed on top.. Below is the execution approach: If Case_Expression is equivalent to Value_1, then further WHENTHEN statements are skipped, and CASE execution will END immediately. What is a word for the arcane equivalent of a monastery? The CASE expression can't be used to control the flow of execution of Transact-SQL statements, statement blocks, user-defined functions, and stored procedures. Apache When. WHEN France THEN Europe However, if youre reaching the limit of 255 expressions, I would be looking at the efficiency of the query itself, as most queries should not need 255 expressions. no it makes no sense, add tables and wanted result, which would make everything much clearer, How Intuit democratizes AI development across teams through reusability. MySQL has a DECODE function but its used for something completely different. All data types for the expression and conditions for the Simple expressions, and all of the results for both expression types must be the same or have a numeric data type. However, Oracle does not have this functionality. WHERE ( The region and polygon don't match. CASE keyword is immediately followed by CASE_Expression and before WHEN statement. Below is the example MS-SQL code: @Order is set to 1 and as first WHEN Boolean expression evaluates to TRUE, Tutorial_ID is selected for Order by Condition, Copyright - Guru99 2023 Privacy Policy|Affiliate Disclaimer|ToS, Difference between Simple and searched case, Oracle vs SQL Server Difference Between Them, What is SQL Server? Theoretically Correct vs Practical Notation. and exists (select x from CELL_STATES cs where cs.cell_id=g.cell_id and cs.name like %||:P835_STATE||%) PROVINCIA Thank you very much for your effort on this topic. Cookie Notice g.itcl_id, vegan) just to try it, does this inconvenience the caterers and staff? . Find all tables containing column with specified name - MS SQL Server, Partner is not responding when their writing is needed in European project application. It can be used in the Insert statement as well. Result: Below diagram explains the execution flow of a SIMPLE CASE with NO ELSE. Has 90% of ice around Antarctica disappeared in less than a decade? Other than that, you just need. Its good for displaying a value in the SELECT query based on logic that you have defined. Hi, if I change your Simple CASE Statement example from above as followed: SELECT What is the purpose of this D-shaped ring at the base of the tongue on my hiking boots? : If all result expressions use the NULL constant, error 8133 is returned. It finds the first match, or the first expression that is evaluated to be a match, and does not continue with the rest. I'm sure it's probably pretty simple but can't see what's wrong. Notice how the expression (in this case the country field) comes right after the CASE keyword. WHERE STPR_STATUSES.POS=1 AND STPR_STATUS=A AND NOT EXISTS SELECT * WHEN USA THEN 1 Thanks, You can use the SELECT with the CASE and all its clauses as a subquery, then in the outer query use the GROUP BY. In the first example, the value in the SalariedFlag column of the HumanResources.Employee table is evaluated. I think you need to add some selects before your sum subqueries. The answer is that it stops after the first match. in "We, who've been connected by blood to Prussia's throne and people since Dppel". It includes equal and not equal to operator. WHEN THEN Statement_1 I don t understand one thing: sometimes (and which are the conditions to be so? (AVG(NULLIF(count_hist, 0))) AS avg_hist How do I get list of all tables in a database using TSQL? The parameter Boolean_Expression_1, denotes the expression which will be evaluated for TRUE or FALSE. current_page_url ilike %optus.com.au/for-you/entertainment% OR In ApexSQL Refactor in the Lists tab under the Columns sub-tab, formatting options can be combined for data statements formatting such as Select, Insert etc. dl_month, In the future someone may add another name to the table so I can't use a Case statement with static names. That is a big difference from 10 minutes on production. reading and return the result. CASE WHEN Col1 = 1 OR Col3 = 1 THEN 1 WHEN Col1 = 2 THEN 2 . union all The following example displays the list price as a text comment based on the price range for a product. Thanks for the comment. Ill demonstrate this using more examples later in this article. Hi Miro, wo , last_chg, case. FROM ( CASE clause uses a rule to return a specific result based on the specified condition, similar to if/else statements in other programming languages. The following example uses the CASE expression in a HAVING clause to restrict the rows returned by the SELECT statement. THEN ACT This example shows all customerswho live inNorth America, using the CASE statement to restrict the records. The database will evaluate the first condition, then compare it to the expression, then evaluate the second condition, then evaluate that to the expression, and so on. IN / NOT IN This operator takes the output of the inner query after the inner query gets executed which can be zero or more values and sends it to the outer query. Nested statements are usually Select statements. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, Make sure your alias is somewhat verbose too! However, it uses an IN clause, which means the value is checked to see if it is in the IN parameter. However, you can use a native SQL statement to achieve the same goal. For example, you can use CASE in statements such as SELECT, UPDATE, DELETE and SET, and in clauses such as , IN, WHERE, ORDER BY, and HAVING. IF() and SWITCH() are two recommended functions for getting the same results as a CASE expression. How can I do an UPDATE statement with JOIN in SQL Server? WHEN MILITARY_STATUSES = VAIR,VANG,VARM,VCG,VMAR,VNAVY,VNG Where does this (supposedly) Gibson quote come from? So, once a condition is true, it will stop reading and return the result. How to follow the signal when reading the schematic? Not the answer you're looking for? group by prod,purchase_flag If so, it should be SELECT *, (CASE WHEN Add the comma after *. How do I UPDATE from a SELECT in SQL Server? The searched CASE expression evaluates a set of Boolean expressions to determine the result. order by 1. SQL Server Lets have a look at SIMPLE CASE example below: Here, Tutorial_name is a part of CASE expression in SQL. This example is using the simple case statement structure. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Employees that have the SalariedFlag set to 0 are returned in order by the BusinessEntityID in ascending order. Msg 125, Level 15, State 4, Line 1. In a SQL database query, a correlated subquery (also known as a synchronized subquery) is a subquery (a query nested inside another query) that uses values from the outer query. purchase_flag GROUP BY dl_month There are two types of CASE statements: Simple case statement: used to enter into some logic based on a literal value Searched case statement: used to enter into some logic based on Is it suspicious or odd to stand by the gate of a GA airport watching the planes? New to PL/SQL in Oracle9 i, the CASE statement allows you to select one sequence of statements to execute out of many possible sequences. The nature of simulating nature: A Q&A with IBM Quantum researcher Dr. Jamie We've added a "Necessary cookies only" option to the cookie consent popup. WHEN UK THEN 3 Required fields are marked *. Theoretically Correct vs Practical Notation. If you preorder a special airline meal (e.g. You did it all without any UNIONs. case-operand. Query 1: SEARCHED CASE with the NO ELSE option. Hello! Below Diagram illustrate the execution flow of Simple Case. Afterwards I illustrate the functionality using a practical example. Do new devs get fired if they can't solve a certain bug? CASE is used within a SQL statement, such as SELECT or UPDATE. Good question. >ALL(100,200,300), the ALL operator will fetch all the values greater than 300. THEN AF END AS TELEFONO. g.cell_id, SELECT columms, CASE A nested query is a SELECT statement that is typically enclosed in parentheses, and embedded within a primary SELECT, INSERT, or DELETE . Im trying to define my WHEN statements by pulling a value from another table using a nested select top 1 statement, and if the value selected is not null then give me my original select, if it is null and another value from the same table is not null then give me hard value else other hard value. How do I perform an IFTHEN in an SQL SELECT? The parameters or components of the CASE SQL statement are: There are actually two ways to use an SQL CASE statement, which are referred to as a simple case expression or a searched case expression. ) GROUP BY prod; The GROUP BY is outside the subquery so it should work. ORDER BY first_name, last_name; Again, I recognize you wouldn't write this exact query. You can use the native CASE WHEN statement to implement the IF - THEN - ELSE logic in your SQL routines. and t1.entity_id = ued.entity_id Statements that include a subquery usually take one of these forms: Check for more subquery rules and subquery types. WHEN MILITARY_STATUSES (ACG,DODCG,FAMCG,RCG,VCG) CASE WHEN THEN Statement_1 In above example, Boolean_Expression_1 can contain both equal to and not equal to operator like A = B, A != B. The region and polygon don't match. THEN ARMY WHEN MILITARY_STATUSES = RAIR,RARMY,RCG,RMAR,RNAVY,RNG I havent tested this query so you might need to tweak it if you get a syntax error. Theoretically Correct vs Practical Notation. A subquery is usually added within the WHERE Clause of another SQL SELECT statement. Structured Query Language (SQL) is used to manage data in a relational database management system (RDBMS). FROM ( Can airtags be tracked from an iMac desktop, with no iPhone? Is it suspicious or odd to stand by the gate of a GA airport watching the planes? By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. current_page_url not ilike %prepaid/checkout%) THEN EXISTS ( and cs.name like %||:P835_STATE||%) Within a SELECT statement, the searched CASE expression allows for values to be replaced in the result set based on comparison values. FECHAACTIVACION AS ALTA, SELECT EMPNO, FIRSTNME, MIDINIT, LASTNAME, CASE WHEN EDLEVEL < 15 THEN 'SECONDARY' WHEN EDLEVEL < 19 THEN 'COLLEGE' ELSE 'POST GRADUATE' END FROM EMPLOYEE. Change Linked; Affidavit Tcs. So far I've tried: Which seems to match the MSDN examples at http://msdn.microsoft.com/en-us/library/ms181765.aspx . NULL N/A Ah, I see what you mean. Syntax: There can be two valid ways of going about the case-switch statements. Is it a bug? Its a common feature of many programming languages. In a nutshell, Condition is Boolean_Expression_1, and ACTION is the execution of Statement_N if above boolean_Expression_1 is TRUE. Get my book: Beginning Oracle SQL for Oracle Database 18c, Copyright 2023 Database Star | Powered by Astra WordPress Theme. If you want to use IF logic, then use the CASE statement. Hi Juan, CASE your_case_criteria AS prod Replacing broken pins/legs on a DIP IC package, Calculating probabilities from d6 dice pool (Degenesis rules for botches and triggers). If there is no ELSE part and no conditions are true, it returns NULL. (SELECT * Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? I moved a copy of the database from production DB (SQL 2005) to my local machine running SQL 2008, and then indexed the copy of the database. NUMERODOCUMENTO AS DNI, This example performs a searched CASE using a number field, which is the number of employees. How do you get out of a corner when plotting yourself into a corner. The CASE expression is a conditional expression, similar to if/then/else statements found in other languages. Did any DOS compatibility layers exist for any UNIX-like systems before DOS started to become outmoded? CASE can be used in any statement or clause that allows a valid expression. rev2023.3.3.43278. In this article, we would explore the CASE statement and its various use cases. group by to_char(dldate,YYYY-MM))) d Both formats support an optional ELSE argument. If there is no ELSE part and no conditions are true, it returns NULL. FROM PERMIL_STATUSES union all If Boolean_expression_1 is FALSE, then Boolean_expression_2 is evaluated for TRUE condition. By rejecting non-essential cookies, Reddit may still use certain cookies to ensure the proper functionality of our platform. END. ELSE Unknown They've been part of the SQL standard since 1992, although Oracle SQL didn't . Any Errors or Warnings? 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? CASE country Is it possible to create a concave light? How do I align things in the following tabular environment? In MS SQL, there are two types of CASE: Simple CASE and Searched CASE. Notify me of follow-up comments by email. The answer provided by Joe Stefanelli is already correct. first_name, last_name, country, STEP 2: Using C_ID of step 1 for finding S_ID. In Oracle, there is no IF statement or keyword specifically in Oracle. The CASE statement should exit when it reaches the first TRUE condition. ON SUBSTRING(STPR_STATUSES.STUDENT_PROGRAMS_ID, 1, 7) = (MILITARY_ASSOC.ID) Connect and share knowledge within a single location that is structured and easy to search. The outer query then fetches all the matching [IN operator] or non matching [NOT IN operator] rows.