跟进：Is this XML format correct?
我有一些SQL代码在QABLOCK中循环并打印它们（PRINTs将在生产中更改为INSERT）。
-- XML instance
DECLARE @x1 XML
SELECT @x1 =
'
<tests>
<test id="1">
<qablock number="1">
<question>What is 1 + 1?</question>
<explanation>It"s 2.</explanation>
<options>
<option number="1" value="1" correct="0" />
<option number="2" value="2" correct="1" />
<option number="3" value="3" correct="0" />
<option number="4" value="4" correct="0" />
<option number="5" value="5" correct="0" />
</options>
</qablock>
<qablock number="2">
<question>What is 2 + 2?</question>
<explanation>It"s 4.</explanation>
<options>
<option number="1" value="1" correct="0" />
<option number="2" value="2" correct="0" />
<option number="3" value="3" correct="0" />
<option number="4" value="4" correct="1" />
<option number="5" value="5" correct="0" />
</options>
</qablock>
</test>
</tests>
'
DECLARE
@cnt INT,
@totCnt INT,
@child XML
-- counter variables
SELECT
@cnt = 1,
@totCnt = @x1.value('count(/tests/test/qablock)','INT')
-- loop
WHILE @cnt <= @totCnt BEGIN
SELECT
1 AS tests_id, --this is hard-coded
@cnt AS qablock_number,
@x1.value('(/tests/test/qablock[position()=sql:variable("@cnt")]/question/text())[1]','varchar(500)') AS question,
@x1.value('(/tests/test/qablock[position()=sql:variable("@cnt")]/explanation/text())[1]','varchar(1000)') AS explanation
PRINT 'Processing Child Element: ' + CAST(@cnt AS VARCHAR)
PRINT 'Child element: ' + CAST(@child AS VARCHAR(max))
PRINT ''
-- increment the counter variable
SELECT @cnt = @cnt + 1
END
我不知道这是否是正确的程序，但至少它似乎有效。我接下来要做的是运行另一个类似的脚本，它循环遍历所有的OPTION和PRINT。对于每个OPTION，我需要打印：QABLOCK编号，OPTION编号，OPTION值和OPTION is_correct。我甚至无法接近。 :(这是我到目前为止所得到的：
-- XML instance
DECLARE @x1 XML
SELECT @x1 =
'
<tests>
<test id="1">
<qablock number="1">
<question>What is 1 + 1?</question>
<explanation>It"s 2.</explanation>
<options>
<option number="1" value="1" correct="0" />
<option number="2" value="2" correct="1" />
<option number="3" value="3" correct="0" />
<option number="4" value="4" correct="0" />
<option number="5" value="5" correct="0" />
</options>
</qablock>
<qablock number="2">
<question>What is 2 + 2?</question>
<explanation>It"s 4.</explanation>
<options>
<option number="1" value="1" correct="0" />
<option number="2" value="2" correct="0" />
<option number="3" value="3" correct="0" />
<option number="4" value="4" correct="1" />
<option number="5" value="5" correct="0" />
</options>
</qablock>
</test>
</tests>
'
DECLARE
@cnt INT,
@totCnt INT,
@child XML
-- counter variables
SELECT
@cnt = 1,
@totCnt = @x1.value('count(/tests/test/qablock/options/option)','INT')
-- loop
WHILE @cnt <= @totCnt BEGIN
SELECT
1 AS tests_id, --hard-coded value
@x1.value('(/tests/test/qablock/@number)[1]','varchar(500)') AS qablock_number,
@x1.value('(/tests/test/qablock/options/option[position()=sql:variable("@cnt")]/@number)[1]','varchar(500)') AS option_number
PRINT 'Processing Child Element: ' + CAST(@cnt AS VARCHAR)
PRINT 'Child element: ' + CAST(@child AS VARCHAR(max))
PRINT ''
-- increment the counter variable
SELECT @cnt = @cnt + 1
END
所以，显然它已经搞砸了，但我似乎无法弄清楚要改变什么。
首先，我不知道如何获取当前OPTION的父QABLOCK编号。
其次，只有我的前5个option_number正确显示其数字，第二个5显示为NULL。
答案 0 :(得分：1)
这应该可以解决问题：
-- XML instance
DECLARE @x1 XML
SELECT @x1 =
'
<tests>
<test id="1">
<qablock number="1">
<question>What is 1 + 1?</question>
<explanation>It"s 2.</explanation>
<options>
<option number="1" value="1" correct="0" />
<option number="2" value="2" correct="1" />
<option number="3" value="3" correct="0" />
<option number="4" value="4" correct="0" />
<option number="5" value="5" correct="0" />
</options>
</qablock>
<qablock number="2">
<question>What is 2 + 2?</question>
<explanation>It"s 4.</explanation>
<options>
<option number="1" value="1" correct="0" />
<option number="2" value="2" correct="0" />
<option number="3" value="3" correct="0" />
<option number="4" value="4" correct="1" />
<option number="5" value="5" correct="0" />
</options>
</qablock>
</test>
</tests>
'
declare @testCount int
, @testIndex int
, @qaCount int
, @qaIndex int
, @optCount int
, @optIndex int
, @testId int
, @qaNo int
, @question nvarchar(500)
, @explanation nvarchar(500)
, @optNo int
, @optVal int
, @optCorrect bit
--for each test
set @testCount = @x1.value('count(/tests/test)','int')
set @testIndex = 1
while @testIndex <= @testCount
begin
--insert a record for this test
set @testId = @x1.value('(/tests/test[sql:variable(''@testIndex'')]/@id)[1]','int')
print 'insert into tests (id, ...) values (' + + cast(@testId as nvarchar(9)) + ')'
print 'set @testIdDB = scope_identity()' --if we're using db generated ids rather than relying on the ids in the imported xml
--for each qablock
set @qaCount = @x1.value('count(/tests/test[sql:variable(''@testIndex'')]/qablock)','int')
set @qaIndex = 1
while @qaIndex <= @qaCount
begin
--insert a qa record
select @qaNo = @x1.value('(/tests/test[sql:variable(''@testIndex'')]/qablock[sql:variable(''@qaIndex'')]/@number)[1]','int')
, @question = @x1.value('(/tests/test[sql:variable(''@testIndex'')]/qablock[sql:variable(''@qaIndex'')]/question/text())[1]','nvarchar(500)')
, @explanation = @x1.value('(/tests/test[sql:variable(''@testIndex'')]/qablock[sql:variable(''@qaIndex'')]/explanation/text())[1]','nvarchar(500)')
print 'insert into qa (testId, qaNo, Question, Explanation) values (@testIdDB, ' + cast(@qaNo as nvarchar(9)) + ', ' + quotename(@question,'''') + ', ' + quotename(@explanation,'''') + ')'
print 'set @qaIdDB = scope_identity()'
--for each option
set @optCount = @x1.value('count(/tests/test[sql:variable(''@testIndex'')]/qablock[sql:variable(''@qaIndex'')]/options/option)','int')
set @optIndex = 1
while @optIndex <= @optCount
begin
--insert an option record
select @optNo = @x1.value('(/tests/test[sql:variable(''@testIndex'')]/qablock[sql:variable(''@qaIndex'')]/options/option[sql:variable(''@optIndex'')]/@number)[1]','int')
, @optVal = @x1.value('(/tests/test[sql:variable(''@testIndex'')]/qablock[sql:variable(''@qaIndex'')]/options/option[sql:variable(''@optIndex'')]/@value)[1]','int')
, @optCorrect = @x1.value('(/tests/test[sql:variable(''@testIndex'')]/qablock[sql:variable(''@qaIndex'')]/options/option[sql:variable(''@optIndex'')]/@correct)[1]','bit')
print 'insert into tests (qaId, number, value, isCorrect) values (@qaIdDB, ' + cast(@optNo as nvarchar(9)) + ', ' + cast(@optVal as nvarchar(9)) + ', ' + cast(@optCorrect as nchar(1)) + ')'
set @optIndex = @optIndex + 1
end
set @qaIndex = @qaIndex + 1
end
set @testIndex = @testIndex + 1
end
或者更好（感谢您提供给我的链接）：
select x.value('@id','int') testId
FROM @x1.nodes('/tests/test') d(x)
select x.value('../@id','int') parentTestId
, x.value('@number','int') qaNumber
, x.value('(question/text())[1]','nvarchar(500)') question
, x.value('(explanation/text())[1]','nvarchar(500)') explanation
FROM @x1.nodes('/tests/test/qablock') d(x)
select x.value('../../@number','int') parentQaNumber
, x.value('@number','int') number
, x.value('@value','int') value
, x.value('@correct','bit') correct
FROM @x1.nodes('/tests/test/qablock/options/option') d(x)