Question

我正在尝试创建一个SQL case语句，其中一个then语句将有多个动作。不确定这是否可能，以下查询的这部分( @ItemCountVariable = a.ItemCount + 10)不起作用，但这正是我想要实现的。

DECLARE @ItemCountVariable INT = 0
...

WHEN MATCHED THEN
UPDATE SET Name = a.Name, 
           [Description] = a.[Description],
           ItemCount =
            (CASE WHEN  ((a.ItemCount + 10) < 20)
                    THEN a.ItemCount + 10
                  ELSE a.ItemCount, @ItemCountVariable = a.ItemCount + 10
            END)
...

Answer 1

正如jarlh在评论中所写，<form method="POST" action="{% url 'account_change_password' %}" class="password_change signup"> {{form.non_field_errors}} {% csrf_token %} <p><label for="id_oldpassword">Current Password:</label> <input id="id_oldpassword" name="oldpassword" placeholder="Current Password" type="password" required class="sigup_input"/></p> <p>{{form.oldpassword.errors}}</p> <p><label for="id_password1">New Password:</label> <input id="id_password1" name="password1" placeholder="New Password" type="password" required class="sigup_input"/></p> <p>{{form.password1.errors}}</p> <p><label for="id_password2">New Password (again):</label> <input id="id_password2" name="password2" placeholder="New Password (again)" type="password" required class="sigup_input"/></p> <p>{{form.password2.errors}}</p> <button type="submit" name="action">{% trans "Change Password" %}</button> </form>是一种表达，而不是一种陈述这意味着case返回单个值，不能用作流控制元素。有关更多信息，请参阅MSDN官方文档中有关case的相关qoute :(我已加粗相关部分）

备注
  SQL Server在CASE表达式中只允许10个级别的嵌套。

CASE表达式不能用于控制Transact-SQL语句，语句块，用户定义函数和存储过程的执行流程。有关控制流方法的列表，请参阅Control-of-Flow Language (Transact-SQL).

Answer 2

跟着BEGIN...END

DECLARE @Iteration Integer = 0;
WHILE @Iteration <10  
BEGIN  
    SELECT FirstName, MiddleName   
    FROM dbo.DimCustomer WHERE LastName = 'Adams';
    SET @Iteration += 1  ;
END;

当时有多个动作的SQL Case语句

2 个答案: