이 문서에서는 SQL Server에서 WHILE 루프를 사용하는 방법에 대한 전체 개요를 설명합니다. ㅏ WHILE 루프는 지정된 조건이 만족될 때까지 일련의 명령문을 반복적으로 실행하는 데 사용되는 제어 흐름 명령문입니다. . 이 루프는 주어진 조건으로 시작하여 이를 평가하고, 그것이 TRUE이면 추가 실행을 위해 명령문이 루프 내부로 이동합니다. 조건이 FALSE가 되면 실행되지 않습니다. 이는 SQL Server의 while 루프가 0회 이상 실행될 수 있음을 의미합니다.
WHILE 루프의 흐름도
다음 순서도에서는 SQL Server 내 WHILE 루프의 전체 워크플로를 설명합니다.
60개 중 10개는 무엇인가요?
이 차트에서 매 반복마다 지정된 조건을 확인하고, 평가 결과에 따라 코드 흐름이 결정되는 것을 볼 수 있습니다. 결과가 TRUE로 평가되면 제어 흐름은 추가 실행을 위해 루프 내부로 이동합니다. 평가 결과가 FALSE이면 제어 흐름이 루프를 종료하고 루프 외부의 모든 문이나 쿼리가 실행됩니다.
통사론
다음 구문은 SQL Server의 WHILE 루프를 보여줍니다.
WHILE boolean_condition BEGIN BREAK END;
이 구문에는 다음과 같은 매개변수 또는 인수가 있습니다.
WHILE 루프 예
예제를 통해 SQL Server에서 WHILE 루프가 어떻게 작동하는지 이해해 보겠습니다. 주어진 예에서 우리는 먼저 다음의 값을 선언했습니다. 정수형 그 값을 1로 설정합니다. 다음으로 WHILE 루프는 조건을 확인하고, 진실 , 인쇄문이 인쇄됩니다. 루프가 될 때 거짓 , WHILE 루프 뒤의 다음 명령문이 인쇄됩니다.
DECLARE @stud_value INT; SET @stud_value = 1; WHILE @stud_value <= 5 begin print 'mark henry'; set @stud_value="@stud_value" + 1; end; 'rose bennet'; < pre> <p>Executing this statement will return the following output:</p> <img src="//techcodeview.com/img/sql-server-tutorials/44/sql-server-while-loop-2.webp" alt="SQL Server WHILE LOOP"> <p>In the above WHILE loop code snippet, we must increment the variable's value after each iteration. See the below part of the above code line as <strong>SET @stud_value = @stud_value + 1</strong> . If we do not write this statement, the loop will execute infinitely because it cannot becomes FALSE.</p> <pre> BEGIN PRINT 'Mark Henry'; SET @stud_value = @stud_value + 1; END; </pre> <h3>Infinite WHILE Loop</h3> <p>An infinite loop occurs when the evaluation of a condition will never be false. Therefore, the loop will never end and be executed forever. The loop in the following code snippet is infinite because the variable's value is not incremented.</p> <pre> DECLARE @stud_value INT; SET @stud_value = 1; WHILE @stud_value <= 5 begin print 'please stop execution!' end; < pre> <p>Executing the loop will display the below output. This loop will never end its execution until we do not cancel their execution of the query manually.</p> <img src="//techcodeview.com/img/sql-server-tutorials/44/sql-server-while-loop-3.webp" alt="SQL Server WHILE LOOP"> <h3>Inserting Records with WHILE Loop</h3> <p>We can also use the WHILE loop to insert records into the defined table. Let us see how to inserts dummy records into the database. First, we will create a table named <strong>'bikeshop'</strong> containing three columns: <strong>Id, bike_name,</strong> and <strong>price</strong> . Execute the following statement to create this table:</p> <pre> CREATE TABLE bikeshop ( Id INT PRIMARY KEY IDENTITY, bike_name VARCHAR (50) NOT NULL, price FLOAT ) </pre> <p>Next, we will use the WHILE loop to insert ten records into this table by executing the following script:</p> <pre> DECLARE @count INT; SET @count = 1; WHILE @count <= 10 begin insert into bikeshop values('bike-' + cast(@count as varchar), @count*5000) set @count="@count" 1; end; < pre> <p>In this code, we have declared a variable @ <strong>count</strong> and then initialize its value with 1 using a SET clause. Next, we have to define the loop body that executes the INSERT statement to add one record in each execution. The <strong>bike_name column</strong> will append the value of a @count variable with the string <strong>Bike</strong> , and the <strong>price</strong> column determines by the value of a @count variable multiplied by <strong>5000</strong> . The loop will execute until the value of the @count variable becomes FALSE. It means the WHILE loop will execute ten times and <strong>inserts ten records</strong> into the table bikeshop.</p> <p>Now, we can verify all the records of the bikeshop table with the SELECT statement. It will display the following output:</p> <img src="//techcodeview.com/img/sql-server-tutorials/44/sql-server-while-loop-4.webp" alt="SQL Server WHILE LOOP"> <h3>BREAK Statement</h3> <p>SQL Server also allows us to use the BREAK statement in the WHILE loop like programming languages. This statement is used to <strong>immediately stop the current iteration of the loop</strong> , and control flow resumes with the next statement after the loop. In general, we will use the <a href="/sql-server-if-else"> <strong>IF...ELSE statement</strong> </a> to check whether or not a condition has occurred.</p> <p>The following example will explain how to use the BREAK statement in the WHILE loop:</p> <pre> DECLARE @count INT; SET @count = 1; WHILE @count = 6 BEGIN BREAK END SET @Count = @Count + 1 END; </pre> <p>Executing the code will display the below output:</p> <img src="//techcodeview.com/img/sql-server-tutorials/44/sql-server-while-loop-5.webp" alt="SQL Server WHILE LOOP"> <p>The value of the variable is first evaluated in this code. If it is TRUE, the control enters into the loop and prints the statement. When the variable value is greater than or equal to 6, control enters the IF...ELSE block and executes the BREAK statement to terminate the loop. If an IF...ELSE block fails to meet the condition; then, the loop will keep running until the condition is changed to FALSE.</p> <h3>CONTINUE Statement</h3> <p>SQL Server also allows us to use the CONTINUE statement in the WHILE loop like programming languages. This statement immediately <strong>terminates the current execution of the loop when the specified condition is met</strong> , and control flow returns to the beginning of the loop. In general, the IF...ELSE statement will be used to test whether or not a condition has been met.</p> <p>The CONTINUE statement in the WHILE loop is demonstrated in the following example. In this example, we'll assume that we wish to use a WHILE loop to <strong>print only odd values</strong> . The CONTINUE statement can be used to do this. This example will first <strong>test</strong> whether the variable value is <strong>odd or even</strong> . If it is even, the execution goes inside the IF…ELSE statement blocks and decrement the variable value by one. Then, it will execute the CONTINUE statement and starts a new iteration from the beginning.</p> <pre> DECLARE @Count INT SET @Count = 1 WHILE (@Count <= 1 2="0" 44 20) begin if @count % set + continue end print 'the odd value is=" + CONVERT(VARCHAR, @Count) SET @Count = @Count + 1 END </pre> <p>Executing the code snippet will display the below output:</p> <img src=" techcodeview.com img sql-server-tutorials sql-server-while-loop-6.webp' alt="SQL Server WHILE LOOP"> <h3>How to implementing paging with WHILE loop in SQL Server?</h3> <p>We can also use the WHILE loop for implementing the paging. Paging allows displaying the subset of records from a table at any particular time. The following example will explain this concept. The WHILE loop in the code will select two records from the bikeshop table at a time. The records that have been chosen are then displayed in the output.</p> <pre> DECLARE @count INT DECLARE @limit INT; SET @count = 0 SET @limit = 2; WHILE @count <10 begin select * from bikeshop order by id offset @count rows fetch next @limit only set + 2; end; < pre> <p>Executing the code snippet will return the below output:</p> <img src="//techcodeview.com/img/sql-server-tutorials/44/sql-server-while-loop-7.webp" alt="SQL Server WHILE LOOP"> <h3>Nested WHILE Loop</h3> <p>The Nested WHILE Loop in SQL Server is simply a WHILE Loop written inside another WHILE Loop. When we work on multi-layered data, the Nested WHILE loops are essential. Because this concept is useful in extracting the layered data when we want to select them, it is recommended to be careful while using the nested loop.</p> <p> <strong>Syntax</strong> </p> <p>The following syntax illustrate the working of the nested WHILE Loop in SQL Server:</p> <pre> WHILE Expression BEGIN WHILE @Val2 <= 10 begin --second while loop statements sql end --this statement is outside the second --which first -- this < pre> <p>Let us explain this syntax step by step:</p> <p> <strong>Step 1:</strong> The loop starts by checking the first WHILE loop condition, and if it finds a false result, it will exit from While Loop. Otherwise, if the result is true, the control goes inside the BEGIN and END block for further execution. This block will start the execution of the second WHILE loop. See step 2.</p> <p> <strong>Step 2:</strong> This step will check the condition in the Nested WHILE Loop, and if it is false, the second loop will be exit and execute the statement outside this. Otherwise, if the result is true, the control goes inside the BEGIN and END block for further execution.</p> <p> <strong>Step 3:</strong> Once all the statements execute from the second WHILE loop, the control goes to the first WHILE and repeats the first step.</p> <p> <strong>Example</strong> </p> <p>The following example will print the multiplication table of 5 up to 10 using the nested WHILE loop.</p> <pre> DECLARE @val1 INT DECLARE @val2 INT SET @val1 = 5 SET @val2 = 1 WHILE @val1 <= 5 44 begin while @val2 <="10" print convert(varchar, @val1) + ' * @val2) techcodeview.com img sql-server-tutorials sql-server-while-loop-8.webp' alt="SQL Server WHILE LOOP"> <h2>Conclusion</h2> <p>The WHILE loop is a useful method when there is a need to execute a SQL script repeatedly. The article explained how to work with the WHILE loop in MS SQL Server to execute operations such as record insertion and pagination with a simple example. Here we have also learned the BREAK and CONTINUE statements to control the WHILE loop iteration.</p> <hr></=></pre></=></pre></10></pre></=></pre></=></pre></=></pre></=> 무한 WHILE 루프
조건의 평가가 결코 거짓이 아닐 때 무한 루프가 발생합니다. 따라서 루프는 끝나지 않고 영원히 실행됩니다. 다음 코드 조각의 루프는 변수 값이 증가하지 않기 때문에 무한합니다.
DECLARE @stud_value INT; SET @stud_value = 1; WHILE @stud_value <= 5 begin print \'please stop execution!\' end; < pre> <p>Executing the loop will display the below output. This loop will never end its execution until we do not cancel their execution of the query manually.</p> <img src="//techcodeview.com/img/sql-server-tutorials/44/sql-server-while-loop-3.webp" alt="SQL Server WHILE LOOP"> <h3>Inserting Records with WHILE Loop</h3> <p>We can also use the WHILE loop to insert records into the defined table. Let us see how to inserts dummy records into the database. First, we will create a table named <strong>'bikeshop'</strong> containing three columns: <strong>Id, bike_name,</strong> and <strong>price</strong> . Execute the following statement to create this table:</p> <pre> CREATE TABLE bikeshop ( Id INT PRIMARY KEY IDENTITY, bike_name VARCHAR (50) NOT NULL, price FLOAT ) </pre> <p>Next, we will use the WHILE loop to insert ten records into this table by executing the following script:</p> <pre> DECLARE @count INT; SET @count = 1; WHILE @count <= 10 begin insert into bikeshop values(\'bike-\' + cast(@count as varchar), @count*5000) set @count="@count" 1; end; < pre> <p>In this code, we have declared a variable @ <strong>count</strong> and then initialize its value with 1 using a SET clause. Next, we have to define the loop body that executes the INSERT statement to add one record in each execution. The <strong>bike_name column</strong> will append the value of a @count variable with the string <strong>Bike</strong> , and the <strong>price</strong> column determines by the value of a @count variable multiplied by <strong>5000</strong> . The loop will execute until the value of the @count variable becomes FALSE. It means the WHILE loop will execute ten times and <strong>inserts ten records</strong> into the table bikeshop.</p> <p>Now, we can verify all the records of the bikeshop table with the SELECT statement. It will display the following output:</p> <img src="//techcodeview.com/img/sql-server-tutorials/44/sql-server-while-loop-4.webp" alt="SQL Server WHILE LOOP"> <h3>BREAK Statement</h3> <p>SQL Server also allows us to use the BREAK statement in the WHILE loop like programming languages. This statement is used to <strong>immediately stop the current iteration of the loop</strong> , and control flow resumes with the next statement after the loop. In general, we will use the <a href="/sql-server-if-else"> <strong>IF...ELSE statement</strong> </a> to check whether or not a condition has occurred.</p> <p>The following example will explain how to use the BREAK statement in the WHILE loop:</p> <pre> DECLARE @count INT; SET @count = 1; WHILE @count = 6 BEGIN BREAK END SET @Count = @Count + 1 END; </pre> <p>Executing the code will display the below output:</p> <img src="//techcodeview.com/img/sql-server-tutorials/44/sql-server-while-loop-5.webp" alt="SQL Server WHILE LOOP"> <p>The value of the variable is first evaluated in this code. If it is TRUE, the control enters into the loop and prints the statement. When the variable value is greater than or equal to 6, control enters the IF...ELSE block and executes the BREAK statement to terminate the loop. If an IF...ELSE block fails to meet the condition; then, the loop will keep running until the condition is changed to FALSE.</p> <h3>CONTINUE Statement</h3> <p>SQL Server also allows us to use the CONTINUE statement in the WHILE loop like programming languages. This statement immediately <strong>terminates the current execution of the loop when the specified condition is met</strong> , and control flow returns to the beginning of the loop. In general, the IF...ELSE statement will be used to test whether or not a condition has been met.</p> <p>The CONTINUE statement in the WHILE loop is demonstrated in the following example. In this example, we'll assume that we wish to use a WHILE loop to <strong>print only odd values</strong> . The CONTINUE statement can be used to do this. This example will first <strong>test</strong> whether the variable value is <strong>odd or even</strong> . If it is even, the execution goes inside the IF…ELSE statement blocks and decrement the variable value by one. Then, it will execute the CONTINUE statement and starts a new iteration from the beginning.</p> <pre> DECLARE @Count INT SET @Count = 1 WHILE (@Count <= 1 2="0" 44 20) begin if @count % set + continue end print \'the odd value is=" + CONVERT(VARCHAR, @Count) SET @Count = @Count + 1 END </pre> <p>Executing the code snippet will display the below output:</p> <img src=" techcodeview.com img sql-server-tutorials sql-server-while-loop-6.webp\' alt="SQL Server WHILE LOOP"> <h3>How to implementing paging with WHILE loop in SQL Server?</h3> <p>We can also use the WHILE loop for implementing the paging. Paging allows displaying the subset of records from a table at any particular time. The following example will explain this concept. The WHILE loop in the code will select two records from the bikeshop table at a time. The records that have been chosen are then displayed in the output.</p> <pre> DECLARE @count INT DECLARE @limit INT; SET @count = 0 SET @limit = 2; WHILE @count <10 begin select * from bikeshop order by id offset @count rows fetch next @limit only set + 2; end; < pre> <p>Executing the code snippet will return the below output:</p> <img src="//techcodeview.com/img/sql-server-tutorials/44/sql-server-while-loop-7.webp" alt="SQL Server WHILE LOOP"> <h3>Nested WHILE Loop</h3> <p>The Nested WHILE Loop in SQL Server is simply a WHILE Loop written inside another WHILE Loop. When we work on multi-layered data, the Nested WHILE loops are essential. Because this concept is useful in extracting the layered data when we want to select them, it is recommended to be careful while using the nested loop.</p> <p> <strong>Syntax</strong> </p> <p>The following syntax illustrate the working of the nested WHILE Loop in SQL Server:</p> <pre> WHILE Expression BEGIN WHILE @Val2 <= 10 begin --second while loop statements sql end --this statement is outside the second --which first -- this < pre> <p>Let us explain this syntax step by step:</p> <p> <strong>Step 1:</strong> The loop starts by checking the first WHILE loop condition, and if it finds a false result, it will exit from While Loop. Otherwise, if the result is true, the control goes inside the BEGIN and END block for further execution. This block will start the execution of the second WHILE loop. See step 2.</p> <p> <strong>Step 2:</strong> This step will check the condition in the Nested WHILE Loop, and if it is false, the second loop will be exit and execute the statement outside this. Otherwise, if the result is true, the control goes inside the BEGIN and END block for further execution.</p> <p> <strong>Step 3:</strong> Once all the statements execute from the second WHILE loop, the control goes to the first WHILE and repeats the first step.</p> <p> <strong>Example</strong> </p> <p>The following example will print the multiplication table of 5 up to 10 using the nested WHILE loop.</p> <pre> DECLARE @val1 INT DECLARE @val2 INT SET @val1 = 5 SET @val2 = 1 WHILE @val1 <= 5 44 begin while @val2 <="10" print convert(varchar, @val1) + \' * @val2) techcodeview.com img sql-server-tutorials sql-server-while-loop-8.webp\' alt="SQL Server WHILE LOOP"> <h2>Conclusion</h2> <p>The WHILE loop is a useful method when there is a need to execute a SQL script repeatedly. The article explained how to work with the WHILE loop in MS SQL Server to execute operations such as record insertion and pagination with a simple example. Here we have also learned the BREAK and CONTINUE statements to control the WHILE loop iteration.</p> <hr></=></pre></=></pre></10></pre></=></pre></=></pre></=>
다음으로 WHILE 루프를 사용하여 다음 스크립트를 실행하여 이 테이블에 10개의 레코드를 삽입합니다.
내 모니터 크기는 얼마야?
DECLARE @count INT; SET @count = 1; WHILE @count <= 10 begin insert into bikeshop values(\'bike-\' + cast(@count as varchar), @count*5000) set @count="@count" 1; end; < pre> <p>In this code, we have declared a variable @ <strong>count</strong> and then initialize its value with 1 using a SET clause. Next, we have to define the loop body that executes the INSERT statement to add one record in each execution. The <strong>bike_name column</strong> will append the value of a @count variable with the string <strong>Bike</strong> , and the <strong>price</strong> column determines by the value of a @count variable multiplied by <strong>5000</strong> . The loop will execute until the value of the @count variable becomes FALSE. It means the WHILE loop will execute ten times and <strong>inserts ten records</strong> into the table bikeshop.</p> <p>Now, we can verify all the records of the bikeshop table with the SELECT statement. It will display the following output:</p> <img src="//techcodeview.com/img/sql-server-tutorials/44/sql-server-while-loop-4.webp" alt="SQL Server WHILE LOOP"> <h3>BREAK Statement</h3> <p>SQL Server also allows us to use the BREAK statement in the WHILE loop like programming languages. This statement is used to <strong>immediately stop the current iteration of the loop</strong> , and control flow resumes with the next statement after the loop. In general, we will use the <a href="/sql-server-if-else"> <strong>IF...ELSE statement</strong> </a> to check whether or not a condition has occurred.</p> <p>The following example will explain how to use the BREAK statement in the WHILE loop:</p> <pre> DECLARE @count INT; SET @count = 1; WHILE @count = 6 BEGIN BREAK END SET @Count = @Count + 1 END; </pre> <p>Executing the code will display the below output:</p> <img src="//techcodeview.com/img/sql-server-tutorials/44/sql-server-while-loop-5.webp" alt="SQL Server WHILE LOOP"> <p>The value of the variable is first evaluated in this code. If it is TRUE, the control enters into the loop and prints the statement. When the variable value is greater than or equal to 6, control enters the IF...ELSE block and executes the BREAK statement to terminate the loop. If an IF...ELSE block fails to meet the condition; then, the loop will keep running until the condition is changed to FALSE.</p> <h3>CONTINUE Statement</h3> <p>SQL Server also allows us to use the CONTINUE statement in the WHILE loop like programming languages. This statement immediately <strong>terminates the current execution of the loop when the specified condition is met</strong> , and control flow returns to the beginning of the loop. In general, the IF...ELSE statement will be used to test whether or not a condition has been met.</p> <p>The CONTINUE statement in the WHILE loop is demonstrated in the following example. In this example, we'll assume that we wish to use a WHILE loop to <strong>print only odd values</strong> . The CONTINUE statement can be used to do this. This example will first <strong>test</strong> whether the variable value is <strong>odd or even</strong> . If it is even, the execution goes inside the IF…ELSE statement blocks and decrement the variable value by one. Then, it will execute the CONTINUE statement and starts a new iteration from the beginning.</p> <pre> DECLARE @Count INT SET @Count = 1 WHILE (@Count <= 1 2="0" 44 20) begin if @count % set + continue end print \'the odd value is=" + CONVERT(VARCHAR, @Count) SET @Count = @Count + 1 END </pre> <p>Executing the code snippet will display the below output:</p> <img src=" techcodeview.com img sql-server-tutorials sql-server-while-loop-6.webp\' alt="SQL Server WHILE LOOP"> <h3>How to implementing paging with WHILE loop in SQL Server?</h3> <p>We can also use the WHILE loop for implementing the paging. Paging allows displaying the subset of records from a table at any particular time. The following example will explain this concept. The WHILE loop in the code will select two records from the bikeshop table at a time. The records that have been chosen are then displayed in the output.</p> <pre> DECLARE @count INT DECLARE @limit INT; SET @count = 0 SET @limit = 2; WHILE @count <10 begin select * from bikeshop order by id offset @count rows fetch next @limit only set + 2; end; < pre> <p>Executing the code snippet will return the below output:</p> <img src="//techcodeview.com/img/sql-server-tutorials/44/sql-server-while-loop-7.webp" alt="SQL Server WHILE LOOP"> <h3>Nested WHILE Loop</h3> <p>The Nested WHILE Loop in SQL Server is simply a WHILE Loop written inside another WHILE Loop. When we work on multi-layered data, the Nested WHILE loops are essential. Because this concept is useful in extracting the layered data when we want to select them, it is recommended to be careful while using the nested loop.</p> <p> <strong>Syntax</strong> </p> <p>The following syntax illustrate the working of the nested WHILE Loop in SQL Server:</p> <pre> WHILE Expression BEGIN WHILE @Val2 <= 10 begin --second while loop statements sql end --this statement is outside the second --which first -- this < pre> <p>Let us explain this syntax step by step:</p> <p> <strong>Step 1:</strong> The loop starts by checking the first WHILE loop condition, and if it finds a false result, it will exit from While Loop. Otherwise, if the result is true, the control goes inside the BEGIN and END block for further execution. This block will start the execution of the second WHILE loop. See step 2.</p> <p> <strong>Step 2:</strong> This step will check the condition in the Nested WHILE Loop, and if it is false, the second loop will be exit and execute the statement outside this. Otherwise, if the result is true, the control goes inside the BEGIN and END block for further execution.</p> <p> <strong>Step 3:</strong> Once all the statements execute from the second WHILE loop, the control goes to the first WHILE and repeats the first step.</p> <p> <strong>Example</strong> </p> <p>The following example will print the multiplication table of 5 up to 10 using the nested WHILE loop.</p> <pre> DECLARE @val1 INT DECLARE @val2 INT SET @val1 = 5 SET @val2 = 1 WHILE @val1 <= 5 44 begin while @val2 <="10" print convert(varchar, @val1) + \' * @val2) techcodeview.com img sql-server-tutorials sql-server-while-loop-8.webp\' alt="SQL Server WHILE LOOP"> <h2>Conclusion</h2> <p>The WHILE loop is a useful method when there is a need to execute a SQL script repeatedly. The article explained how to work with the WHILE loop in MS SQL Server to execute operations such as record insertion and pagination with a simple example. Here we have also learned the BREAK and CONTINUE statements to control the WHILE loop iteration.</p> <hr></=></pre></=></pre></10></pre></=></pre></=>
코드를 실행하면 아래 출력이 표시됩니다.
이 코드에서는 변수 값이 먼저 평가됩니다. TRUE이면 컨트롤이 루프에 들어가 명령문을 인쇄합니다. 변수 값이 6보다 크거나 같으면 제어 장치는 IF...ELSE 블록에 들어가고 BREAK 문을 실행하여 루프를 종료합니다. IF...ELSE 블록이 조건을 충족하지 못하는 경우 그러면 조건이 FALSE로 변경될 때까지 루프가 계속 실행됩니다.
CONTINUE 문
SQL Server에서는 프로그래밍 언어와 마찬가지로 WHILE 루프에서 CONTINUE 문을 사용할 수도 있습니다. 이 발언은 즉시 지정된 조건이 충족되면 루프의 현재 실행을 종료합니다. , 제어 흐름은 루프의 시작 부분으로 돌아갑니다. 일반적으로 IF...ELSE 문은 조건이 충족되었는지 여부를 테스트하는 데 사용됩니다.
다음 예에서는 WHILE 루프의 CONTINUE 문을 보여줍니다. 이 예에서는 WHILE 루프를 사용하여 다음 작업을 수행한다고 가정합니다. 홀수 값만 인쇄 . CONTINUE 문을 사용하여 이를 수행할 수 있습니다. 이 예는 먼저 시험 변수 값이 다음과 같은지 여부 홀수 또는 짝수 . 짝수이면 IF...ELSE 문 블록 내부에서 실행이 진행되고 변수 값이 1씩 감소합니다. 그런 다음 CONTINUE 문을 실행하고 처음부터 새로운 반복을 시작합니다.
C++에서 문자열 분할하기
DECLARE @Count INT SET @Count = 1 WHILE (@Count <= 1 2="0" 44 20) begin if @count % set + continue end print \'the odd value is=" + CONVERT(VARCHAR, @Count) SET @Count = @Count + 1 END </pre> <p>Executing the code snippet will display the below output:</p> <img src=" techcodeview.com img sql-server-tutorials sql-server-while-loop-6.webp\' alt="SQL Server WHILE LOOP"> <h3>How to implementing paging with WHILE loop in SQL Server?</h3> <p>We can also use the WHILE loop for implementing the paging. Paging allows displaying the subset of records from a table at any particular time. The following example will explain this concept. The WHILE loop in the code will select two records from the bikeshop table at a time. The records that have been chosen are then displayed in the output.</p> <pre> DECLARE @count INT DECLARE @limit INT; SET @count = 0 SET @limit = 2; WHILE @count <10 begin select * from bikeshop order by id offset @count rows fetch next @limit only set + 2; end; < pre> <p>Executing the code snippet will return the below output:</p> <img src="//techcodeview.com/img/sql-server-tutorials/44/sql-server-while-loop-7.webp" alt="SQL Server WHILE LOOP"> <h3>Nested WHILE Loop</h3> <p>The Nested WHILE Loop in SQL Server is simply a WHILE Loop written inside another WHILE Loop. When we work on multi-layered data, the Nested WHILE loops are essential. Because this concept is useful in extracting the layered data when we want to select them, it is recommended to be careful while using the nested loop.</p> <p> <strong>Syntax</strong> </p> <p>The following syntax illustrate the working of the nested WHILE Loop in SQL Server:</p> <pre> WHILE Expression BEGIN WHILE @Val2 <= 10 begin --second while loop statements sql end --this statement is outside the second --which first -- this < pre> <p>Let us explain this syntax step by step:</p> <p> <strong>Step 1:</strong> The loop starts by checking the first WHILE loop condition, and if it finds a false result, it will exit from While Loop. Otherwise, if the result is true, the control goes inside the BEGIN and END block for further execution. This block will start the execution of the second WHILE loop. See step 2.</p> <p> <strong>Step 2:</strong> This step will check the condition in the Nested WHILE Loop, and if it is false, the second loop will be exit and execute the statement outside this. Otherwise, if the result is true, the control goes inside the BEGIN and END block for further execution.</p> <p> <strong>Step 3:</strong> Once all the statements execute from the second WHILE loop, the control goes to the first WHILE and repeats the first step.</p> <p> <strong>Example</strong> </p> <p>The following example will print the multiplication table of 5 up to 10 using the nested WHILE loop.</p> <pre> DECLARE @val1 INT DECLARE @val2 INT SET @val1 = 5 SET @val2 = 1 WHILE @val1 <= 5 44 begin while @val2 <="10" print convert(varchar, @val1) + \' * @val2) techcodeview.com img sql-server-tutorials sql-server-while-loop-8.webp\' alt="SQL Server WHILE LOOP"> <h2>Conclusion</h2> <p>The WHILE loop is a useful method when there is a need to execute a SQL script repeatedly. The article explained how to work with the WHILE loop in MS SQL Server to execute operations such as record insertion and pagination with a simple example. Here we have also learned the BREAK and CONTINUE statements to control the WHILE loop iteration.</p> <hr></=></pre></=></pre></10></pre></=>