How do you write a conditional statement in PL SQL?
PL/SQL Conditional Statements. PL/SQL IF-THEN Statement. The IF statement accompanies a condition with a sequence of statements enclosed by END IF and THEN. If the condition is true, the statements get executed and if the condition is FALSE or NULL then it does nothing.
What are the control statements in PL SQL?
PL/SQL categories of control statements are: Conditional selection statements, which run different statements for different data values. Loop statements, which run the same statements with a series of different data values. Sequential control statements, which are not crucial to PL/SQL programming.
What are the conditional expressions in SQL?
Following are Conditional Expressions in SQL. The CASE Expression: Let you use IF-THEN-ELSE statements without having to invoke procedures. In a simple CASE expression, the SQL searches for the first WHEN……THEN pair for which expr is equal to comparison_expr and returns return_expr. If above condition is not satisfied, an ELSE clause exists, ...
Do you need Goto in PL SQL?
Unlike the IF and LOOP statements, the sequential control statements GOTO and NULL are not crucial to PL/SQL programming. The GOTO statement, which goes to a specified statement, is seldom needed. Occasionally, it simplifies logic enough to warrant its use.
What are the conditional statements in Oracle?
The condition is a Boolean variable, constant, or expression that evaluates to TRUE, FALSE, or NULL. If condition evaluates to TRUE, the executable statements found after the THEN keyword and before the matching END IF statement are executed. If condition evaluates to FALSE or NULL, those statements are not executed.
What is the use of conditional control statements?
Conditional control allows you to control the program's flow of the execution based on a condition. In programming terms, this means that the statements in the program are not executed sequentially. Rather, one group of statements or another is executed, depending on how the condition is evaluated.
What are different types of statements in PL SQL?
Types of SQL StatementsData Definition Language (DDL) Statements.Data Manipulation Language (DML) Statements.Transaction Control Statements.Session Control Statements.System Control Statement.Embedded SQL Statements.
What is a conditional in SQL?
Conditional statements are used to define what logic is to be executed based on the status of some condition being satisfied. There are two types of conditional statements supported in SQL procedures: CASE. IF.
What are the 4 conditional statements?
What Are Conditionals?General truth – If I eat breakfast, I feel good all day.Future event – If I have a test tomorrow, I will study tonight.Hypothetical situation – If I had a million dollars, I would buy a boat!Hypothetical outcome – If I had prepared for the interview, I would have gotten the job.
What is the use of conditional statement explain with example?
Example: We have a conditional statement If it is raining, we will not play. Let, A: It is raining and B: we will not play. Then; If A is true, that is, it is raining and B is false, that is, we played, then the statement A implies B is false.
What are types of conditional statements?
There are the following types of conditional statements in C.If statement.If-Else statement.Nested If-else statement.If-Else If ladder.Switch statement.
What is conditional statement and its types?
The conditional statements if, if-else, and switch allow us to choose which statement will be executed next. • Each choice or decision is based on the value of a boolean expression (also called the condition).
How many types of functions are there in PL SQL?
The list of Oracle/PLSQL functions is sorted into the type of function based on categories such as string/character, conversion, advanced, numeric/mathematical, and date/time. These functions can be used in SQL statements or queries in Oracle.
What is the conditional of a statement?
A conditional statement is a statement that can be written in the form “If P then Q,” where P and Q are sentences. For this conditional statement, P is called the hypothesis and Q is called the conclusion. Intuitively, “If P then Q” means that Q must be true whenever P is true.
Why is it called a conditional statement?
Conditional sentences are natural language sentences that express that one thing is contingent on something else, e.g. "If it rains, the picnic will be cancelled." They are so called because the impact of the main clause of the sentence is conditional on the dependent clause.
What is the advantages of conditional statement?
Advantages of Conditional Statements: A conditional statement has many benefits. It can organize a program into logical segments of code that run only if certain conditions are met. It also makes a program more robust by allowing only a portion of code to run if a condition has been met.
What is statement in PL SQL?
PL/SQL has three categories of control statements: Conditional selection statements, which run different statements for different data values. The conditional selection statements are IF and and CASE . Loop statements, which run the same statements with a series of different data values.
What are the different types of statement explain?
There are three kinds of statements: expression statements, declaration statements, and control flow statements. You can group zero or more statements together into a block with braces: { and } .
What are the 5 types of SQL?
There are five types of SQL commands: DDL, DML, DCL, TCL, and DQL.
How many types of statement are there?
The 4 English Sentence Typesformfunction1declarativestatement: It tells us something2interrogativequestion: It asks us something3imperativecommand: It tells us to do something4exclamativeexclamation: It expresses surprise
What are the conditions in PL/SQL?
Decision-making structures require that the programmer specify one or more conditions to be evaluated or tested by the program, along with a statement or statements to be executed if the condition is determined to be true, and optionally, other statements to be executed if the condition is determined to be false.
What is an if statement?
The IF statement associates a condition with a sequence of statements enclosed by the keywords THEN and END IF. If the condition is true, the statements get executed and if the condition is false or NULL then the IF statement does nothing. 2. IF-THEN-ELSE statement.
What is a selector in a case?
A selector is an expression whose value is used to select one of several alternatives.
What happens if a condition is true?
If the condition is true, the statements run; otherwise, the IF statement does nothing. (For complete syntax, see "IF Statement" .)
How many times does the for loop statement execute?
In Example 4-25, the FOR LOOP statement executes 10 times unless the FETCH statement inside it fails to return a row, in which case it ends immediately.
How many exit when statements are there in an inner loop?
In Example 4-11, one basic LOOP statement is nested inside the other, and both have labels. The inner loop has two EXIT WHEN statements; one that exits the inner loop and one that exits the outer loop.
What does "if then elsif" mean?
The IF THEN ELSIF statement runs the first statements for which condition is true. Remaining conditions are not evaluated. If no condition is true, the else_statements run, if they exist; otherwise, the IF THEN ELSIF statement does nothing. (For complete syntax, see "IF Statement" .)
What does a searched case statement do?
The searched CASE statement runs the first statements for which condition is true. Remaining conditions are not evaluated. If no condition is true, the CASE statement runs else_statements if they exist and raises the predefined exception CASE_NOT_FOUND otherwise. (For complete syntax, see "CASE Statement" .)
How to process rows in a query?
To process the rows of a query result set, use a cursor FOR LOOP, which has a query instead of a range of integers. For details, see "Query Result Set Processing With Cursor FOR LOOP Statements".
When does the exit when statement exit?
The EXIT WHEN statement exits the current iter ation of a loop when the condition in its WHEN clause is true , and transfers control to the end of either the current loop or an enclosing labeled loop.
What happens if the condition is true?
If the condition is true, the statements run; otherwise, the IF statement does nothing.
What does the CONTINUE statement do?
The CONTINUE statement exits the current iteration of a loop unconditionally and transfers control to the next iteration of either the current loop or an enclosing labeled loop.
What does "if then elsif" mean?
The IF THEN ELSIF statement runs the first statements for which condition is true. Remaining conditions are not evaluated. If no condition is true, the else_statements run, if they exist; otherwise, the IF THEN ELSIF statement does nothing. (For complete syntax, see " IF Statement " .)
How to process rows in a query?
To process the rows of a query result set, use a cursor FOR LOOP, which has a query instead of a range of integers. For details, see " Processing Query Result Sets With Cursor FOR LOOP Statements ".
How many exit when statements are there in an inner loop?
The inner loop has two EXIT WHEN statements; one that exits the inner loop and one that exits the outer loop. An EXIT WHEN statement in an inner loop can transfer control to an outer loop only if the outer loop is labeled.
When does the exit when statement exit?
The EXIT WHEN statement exits the current iter ation of a loop when the condition in its WHEN clause is true , and transfers control to the end of either the current loop or an enclosing labeled loop.
Can a simple case statement be matched by a null?
As in a simple CASE expression, if the selector in a simple CASE statement has the value NULL, it cannot be matched by WHEN NULL (see Example 2-51 ). Instead, use a searched CASE statement with WHEN condition IS NULL (see Example 2-53 ).
Why is decision making important in PL/SQL?
Decision-Making is an important part for most of the computer programs. It helps to develop the program code logically. For correct decision making, PL/SQL provides us with the Conditional Statements. These Conditional Statements helps us to develop a proper algorithm and a logical program .
What is an if statement?
The IF statement accompanies a condition with a sequence of statements enclosed by END IF and THEN. If the condition is true, the statements get executed and if the condition is FALSE or NULL then it does nothing. The control passes to the succeeding statements in any case.
Is the ELSE clause mandatory?
The ELSE clause is not mandatory to write. If you omit it, PL/SQL adds the ELSE block implicitly.
Is case statement efficient?
The CASE statement is efficient compared to IF statements and hence if the IF-THEN-ELSE programs become lengthy, it is recommended to use CASE statements.
When to use if statement?
The if statement, or the if...then statement can be used when there is only a single condition to be tested. If the result of the condition is TRUE then certain specified action will be performed otherwise if it is FALSE then no action is taken and the control of program will just move out of the if code block.
What is decision making statement?
Decision making statements are those statements which are in charge of executing a statement out of multiple given statements based on some condition. The condition will return either true or false. Based on what the condition returns, the associated statement is executed. For example, if someone says, If I get 40 marks, I will pass the exam, ...
Can you specify two statements?
Using this statement group we can specify two statements or two set of statements, dependent on a condition such that when the condition is true then one set of statements is executed and if the condition is false then the other set of statements is executed .
Can decision making statements be implemented in PL/SQL?
This can be logically implemented in PL/SQL block using decision making statements.
Can you have multiple Elsif statements?
As you can se in the syntax above, we can have multiple elsif statements with as many conditions as we want. Below we have a diagram or we can say a flowchart:
What is conditional statement?
Conditional statements allow to execute commands according to a certain condition.
What is an ELSE condition?
ELSE condition contains commands to run if the condition set by IF is not true.
Can a case condition be used with operators?
The CASE condition can also be used with operators.
Can conditional expressions be used in loops?
Conditional expressions can also be used in loops.
What is PL/SQL in Oracle?
PL/SQL is a block structured language that enables developers to combine the power of SQL with procedural statements.All the statements of a block are passed to oracle engine all at once which increases processing speed and decreases the traffic.
What is PL/SQL programming?
PL/SQL is basically a procedural language, which provides the functionality of decision making, iteration and many more features of procedural programming languages. PL/SQL can execute a number of queries in one block using single command.
What is var1 in SQL?
var1 INTEGER : It is the declaration of variable, named var1 which is of integer type. There are many other data types that can be used like float, int, real, smallint, long etc. It also supports variables used in SQL as well like NUMBER (prec, scale), varchar, varchar2 etc.
What is a SQL query?
SQL is a single query that is used to perform DML and DDL operations. It is declarative, that defines what needs to be done, rather than how things need to be done. PL/SQL is procedural that defines how the things needs to be done. Execute as a single statement. Execute as a whole block.
What is the declaration section in SQL?
Declare section starts with DECLARE keyword in which variables, constants, records as cursors can be declared which stores data temporarily. It basically consists definition of PL/SQL identifiers. This part of the code is optional.
What are PL/SQL identifiers?
PL/SQL identifiers. There are several PL/SQL identifiers such as variables, constants, procedures, cursors, triggers etc. Like several other programming languages, variables in PL/SQL must be declared prior to its use. They should have a valid name and data type as well.
What is multi line comment?
Multi Line Comment: To create comments that span over several lines, the symbol /* and */ is used.