如果发现有关如何将表（或查询）转换为XML的几个问题，但没有一个问题显示如何从一个主表开始并连接多个主表：许多卫星表，并从中生成表示层次结构的XML的数据。所以我想我现在已经把它解决了，所以我会分享这个解决方案。如果其他人有另一种方法，请发布另一个答案。
鉴于这些人为的数据：
create table #recipe (id int, name varchar(10))
create table #ingredient (recipe_id int, name varchar(30), quantity varchar(20), sort int)
create table #instruction (recipe_id int, task varchar(32), sort int)
insert into #recipe values (1, 'pizza'), (2, 'omelet')
insert into #ingredient values (1, 'pizza dough', '1 package', 1),
(1, 'tomato sauce', '1 can', 2),
(1, 'favorite toppings', 'you choose', 3),
(2, 'eggs', 'three', 1),
(2, 'a bunch of other ingredients', 'you choose', 2)
insert into #instruction values (1, 'pre-bake pizza dough', 1),
(1, 'add tomato sauce', 2),
(1, 'add toppings', 3),
(1, 'bake a little longer', 4),
(2, 'break eggs into mixing bowl', 1),
(2, 'beat yolks and whites together', 2),
(2, 'pour into large sauce pan', 3),
(2, 'add other ingredients', 4),
(2, 'fold in half', 5),
(2, 'cook until done', 6)
以表格形式显示如下：
#recipe id name
----------- ----------
1 pizza
2 omelet
#ingredient recipe_id name quantity sort
----------- ------------------------------ -------------------- -----------
1 pizza dough 1 package 1
1 tomato sauce 1 can 2
1 favorite toppings you choose 3
2 eggs three 1
2 a bunch of other ingredients you choose 2
#instruction recipe_id task sort
----------- -------------------------------- -----------
1 pre-bake pizza dough 1
1 add tomato sauce 2
1 add toppings 3
1 bake a little longer 4
2 break eggs into mixing bowl 1
2 beat yolks and whites together 2
2 pour into large sauce pan 3
2 add other ingredients 4
2 fold in half 5
2 cook until done 6
我想创建一个XML文档，每个配方都有一条记录，在每个配方元素中，我想要一组成分和另一组指令，如下所示：
<recipes>
<recipe id="2" name="omelet">
<ingredients>
<ingredient name="eggs" quantity="three" />
<ingredient name="a bunch of other ingredients" quantity="you choose" />
</ingredients>
<instructions>
<instruction task="break eggs into mixing bowl" />
<instruction task="beat yolks and whites together" />
<instruction task="pour into large sauce pan" />
<instruction task="add other ingredients" />
<instruction task="fold in half" />
<instruction task="cook until done" />
</instructions>
</recipe>
<recipe id="1" name="pizza">
<ingredients>
<ingredient name="pizza dough" quantity="1 package" />
<ingredient name="tomato sauce" quantity="1 can" />
<ingredient name="favorite toppings" quantity="you choose" />
</ingredients>
<instructions>
<instruction task="pre-bake pizza dough" />
<instruction task="add tomato sauce" />
<instruction task="add toppings" />
<instruction task="bake a little longer" />
</instructions>
</recipe>
</recipes>
答案 0 :(得分：2)
此SQL逐字创建所需的XML：
select recipe.*,
(
select ingredient.name, ingredient.quantity
from #ingredient ingredient
where recipe.id = ingredient.recipe_id
order by ingredient.sort
for xml auto, root('ingredients'), type
),
(
select instruction.task
from #instruction instruction
where recipe.id = instruction.recipe_id
order by instruction.sort
for xml auto, root('instructions'), type
)
from #recipe as recipe
order by recipe.name
for xml auto, root('recipes'), type
我为临时表名称别名，因为在临时表上使用for xml auto会创建命名不佳的XML元素。这是它的外观：
<recipes>
<recipe id="2" name="omelet">
<ingredients>
<ingredient name="eggs" quantity="three" />
<ingredient name="a bunch of other ingredients" quantity="you choose" />
</ingredients>
<instructions>
<instruction task="break eggs into mixing bowl" />
<instruction task="beat yolks and whites together" />
<instruction task="pour into large sauce pan" />
<instruction task="add other ingredients" />
<instruction task="fold in half" />
<instruction task="cook until done" />
</instructions>
</recipe>
<recipe id="1" name="pizza">
<ingredients>
<ingredient name="pizza dough" quantity="1 package" />
<ingredient name="tomato sauce" quantity="1 can" />
<ingredient name="favorite toppings" quantity="you choose" />
</ingredients>
<instructions>
<instruction task="pre-bake pizza dough" />
<instruction task="add tomato sauce" />
<instruction task="add toppings" />
<instruction task="bake a little longer" />
</instructions>
</recipe>
</recipes>
这个SQL创建了另一个版本的XML，其中所有数据都是值而不是属性，但是在相同的基本层次结构中：
select recipe.*,
(
select ingredient.name, ingredient.quantity
from #ingredient ingredient
where recipe.id = ingredient.recipe_id
order by ingredient.sort
for xml path('ingredient'), root('ingredients'), type
),
(
select instruction.task
from #instruction instruction
where recipe.id = instruction.recipe_id
order by instruction.sort
for xml path('instruction'), root('instructions'), type
)
from #recipe as recipe
order by recipe.name
for xml path('recipe'), root('recipes'), type
它的外观如下：
<recipes>
<recipe>
<id>2</id>
<name>omelet</name>
<ingredients>
<ingredient>
<name>eggs</name>
<quantity>three</quantity>
</ingredient>
<ingredient>
<name>a bunch of other ingredients</name>
<quantity>you choose</quantity>
</ingredient>
</ingredients>
<instructions>
<instruction>
<task>break eggs into mixing bowl</task>
</instruction>
<instruction>
<task>beat yolks and whites together</task>
</instruction>
<instruction>
<task>pour into large sauce pan</task>
</instruction>
<instruction>
<task>add other ingredients</task>
</instruction>
<instruction>
<task>fold in half</task>
</instruction>
<instruction>
<task>cook until done</task>
</instruction>
</instructions>
</recipe>
<recipe>
<id>1</id>
<name>pizza</name>
<ingredients>
<ingredient>
<name>pizza dough</name>
<quantity>1 package</quantity>
</ingredient>
<ingredient>
<name>tomato sauce</name>
<quantity>1 can</quantity>
</ingredient>
<ingredient>
<name>favorite toppings</name>
<quantity>you choose</quantity>
</ingredient>
</ingredients>
<instructions>
<instruction>
<task>pre-bake pizza dough</task>
</instruction>
<instruction>
<task>add tomato sauce</task>
</instruction>
<instruction>
<task>add toppings</task>
</instruction>
<instruction>
<task>bake a little longer</task>
</instruction>
</instructions>
</recipe>
</recipes>
最初，我尝试将主要查询的from子句中的成分和说明与inner join放在配方表中。但是指令都嵌套在配料中，这些配料嵌套在配方中。当我将它们移动到查询的select部分时，它理顺了XML。