sql - 如何转换选择查询

Question

我有 DDL:

drop table names
drop table salary

create table names(
id int, 
name1 varchar(50),
char1 varchar(50),
char2 varchar(50))

insert into names values (1,'name1','char1','chara'),
                         (2,'name2','char2','charb'),
                         (3,'name3','char3','charc'),
                         (4,'name4','char4','chard'),
                         (5,'name5','char5','charf');

create table salary(
id int, 
salary int,
bonus int,
oldsalary int)

insert into salary values (1,500,245,354),
                         (2,600,345,246),
                         (3,60,365,334),
                         (4,55,545,364),
                         (5,25,345,374);

并且有许多 SQL 查询(其中之一)

    SELECT n.name1,
       s.salary,
       s.bonus,
       ( s.bonus + s.salary ) AS Sumsalary
FROM   names n
       INNER JOIN salary s
               ON n.id = s.id

我想编写选择查询，从 SQL 查询中使用的表中检索所有字段名，除以此选择查询中的使用情况，并在屏幕截图中提到一些附加信息。

我想从此查询中检索的数据格式:

Answer 1

如果您有权访问系统 View ，您可以获得用于查询的表和列的列表:

;WITH XMLNAMESPACES ('http://schemas.microsoft.com/sqlserver/2004/07/showplan' AS ns)
SELECT DISTINCT st.TEXT AS QueryText, 
                C.value('./@Table', 'varchar(50)') As Tab,
                C.value('./@Column', 'varchar(50)') As Col
FROM sys.dm_exec_cached_plans AS cp
CROSS APPLY sys.dm_exec_query_plan(cp.plan_handle) AS qp
CROSS APPLY sys.dm_exec_sql_text(cp.plan_handle) AS st
CROSS APPLY query_plan.nodes('//ns:ColumnReference') as T(C)
WHERE cp.ObjType = 'Adhoc' AND
      St.Text Like '%s.bonus%' AND
      st.Text Not Like '%WITH XMLNAMESPACES%' AND 
      C.value('./@Table', 'varchar(50)') IS NOT NULL

结果如下:

QueryText            Tab       Col
SELECT n.name1, ...  [Names]   id
SELECT n.name1, ...  [Names]   name1
SELECT n.name1, ...  [Salary]  bonus
SELECT n.name1, ...  [Salary]  id
SELECT n.name1, ...  [Salary]  salary

然后，您可以使用这些结果作为链接到 sys.columns 的一种方式，以确定缺少哪些列等。