Question

我正在尝试使用liquiBase yaml changelog文件在SQL Server中创建一个视图，其中每一行如下：

employee_id | provider_id | days_remaining | employed_dates

并且有三个表

雇员-雇员ID，名字，姓氏
作业-作业ID，员工ID，开始日期，结束日期，提供者ID
分配-作业ID，作业ID，员工ID，开始日期，结束日期，提供者ID
employee_id为行
provider_id是provider_id的{{1}}，为此job_id

end_date

employee_id是上述days_remaining

employee_id

provider_id是上述employed_dates的所有assignment_id的所有employee_id的串联

到目前为止，我的代码：

provider_id

我有两个问题：

是否可以避免重复计算provider_id（以下代码）三次？

databaseChangeLog:
  - changeSet:
  id: 100
  author: 100
  dbms: "mssql"
  changes:
    - createView:
        schemaName: ${schemaName}
        viewName: employee_history_view
        replaceIfExists: true
        selectQuery: >
          SELECT EMPLOYEE.employee_id,
          (
            SELECT TOP 1 provider_id from JOB
            where JOB.employee_id = employee_id
            order by end_date DESC
          ) as provider_id,
          employee.first_name,
          employee.last_name,
          DATEDIFF(DAY,
          (
            SELECT max(ASSIGNMENT.end_Date)
            from ASSIGNMENT
            where ASSIGNMENT.employee_id = EMPLOYEE.employee_id
            and ASSIGNMENT.provider_id = (
                                            SELECT TOP 1 provider_id from JOB
                                            where JOB.employee_id = employee_id
                                            order by end_date DESC
                                          )
            and end_date < getDate()
          ),
          getdate() ) as days_remaining,
          (
            '[' + SUBSTRING (
              (
                SELECT TOP 100 ', {"start":"'+CONVERT(CHAR(10),ASSIGNMENT.start_date,120)+'","end":"'+CONVERT(CHAR(10),ASSIGNMENT.end_date,120)+'"}'
                from ASSIGNMENT
                where ASSIGNMENT.employee_id = EMPLOYEE.employee_id
                and ASSIGNMENT.provider_id = (
                                                SELECT TOP 1 provider_id from JOB
                                                where JOB.employee_id = EMPLOYEE.employee_id
                                                order by end_date DESC
                                              )
                order by program_type DESC
                for xml path ('')
              ), 2, 8000) + ']'
          ) as employed_dates
          FROM ${employeeSchema}.EMPLOYEE

由于liquibase中不支持变量，变量表或CTE，我该怎么办？

是否可以修改上面的内容，以便将每个employee_id列在多行中（针对与该employee_id相关联的每个provider_id）？ UNION无效，因为liquibase不支持循环或某种for-each构造，并且CROSS JOINS无效，因为它将employee_id与每个provider_id配对，无论它们是否关联。

Answer 1

对不起，之前并没有明确考虑，可以通过在末尾添加以下INNER JOIN来解决：

position: absolute

对于Liquibase createView，是否可以存储子搜索的值？

1 个答案: