在上面的test_mysql_while_loop存储过程中: 首先,重复构建str字符串,直到x变量的值大于5。 然后,使用SELECT语句显示最终的字符串。 要注意,如果不初始化x变量的值,那么它默认值为NULL。 因此,WHILE循环语句中的条件始终为TRUE,并且您将有一个不确定的循环,这是不可预料的。 下面来测试test_mysql_while_loopstore...
CREATE PROCEDURE sp_demo_in_parameter(IN p_in INT) BEGIN SELECT p_in; --查询输入参数 SET p_in=2; --修改 select p_in;--查看修改后的值 END; 执行结果: mysql> set @p_in=1 mysql> call sp_demo_in_parameter(@p_in) 略 mysql> select @p_in; 略 以上可以看出,p_in虽然在存储过程中...
Summary: in this tutorial, you will learn about PL/SQL WHILE loop statement to execute a sequence of statements as long as a specified condition is TRUE. Introduction to PL/SQL WHILE loop statement PL/SQL WHILE loop is a control structure that repeatedly executes a code block as long as a...
ID || ' '; END LOOP; --拼接主SQL TARGET_RESULTS := TARGET_RESULTS || 'FROM (SELECT a.PRO_NAME,a.CLASS_NAME,a.ID,a.MAIN_DATA_PRO_CODE,b.TIME '; TARGET_RESULTS := TARGET_RESULTS || 'FROM IEW_V_PRO_USER a LEFT JOIN (SELECT DISTINCT PROJECTID,TIME from V_IEW_ACC_DETAIL_...
在while循环中记录数据值的方法有多种,具体取决于编程语言和应用场景。以下是一些常见的方法: 1. 使用变量:在while循环中,可以使用一个或多个变量来记录数据值。在每次循环迭代中,更新变量的值...
In the stored procedure above: First, we buildstrstring repeatedly until the value of thexvariableis greater than5. Then, we display the final string using theSELECT statement. Notice that if we don’t initialize x variable, its default value isNULL. Therefore the condition in theWHILEloop ...
Then, we display the final string using the SELECT statement. Notice that if we don’t initialize x variable, its default value is NULL. Therefore the condition in the WHILE loop statement is always TRUE and you will have a indefinite loop, which is not expected. REPEAT loop The syntax of...
-- Statement 2 END $$ DELIMITER ; 1. 2. 3. 4. 5. 6. 7. 8. 9. 根据格式就可以定义存储过程,写一些需要的逻辑,增删改查 存储过程还可以传递参数并且也可以定义变量,如下例 DELIMITER $$ CREATE PROCEDURE my_procedure(IN param1 INT, OUT param2 INT) ...
"SELECT INTO" with indexes? "Simple" SQL to check for alpha or numeric charcters isn't working right "String or binary data would be truncated.\r\nThe statement has been terminated." "String or binary data would be truncated" and field specifications “Unable to enlist in the transaction”...
Once I finally figured that you cannot have conditionals in the SQL Query everything seemed to work. Here is the code for anyone else that needs it. It does not take in to account holidays. BEGIN SELECT MONTH(CURDATE()) INTO @curmonth; ...