提取由“:"分隔的字符串的第 n 个字段；存储在 SQL 列中 [英] Extracting nth field of string delimited by ":" stored in a SQL column
问题描述
我有一个包含两个以下列的 SQL 表:
I have a SQL table with the two following columns:
FORMAT Sample
GT:AD:DP:GQ:PL 0/0:233,0:233:99:0,120,1800
GT:AD:DP:GQ:PL 0/1:101,61:220:99:835,0,1859
GT:AD:DP:GQ:PL 0/0:172,0:172:99:0,120,1800
GT:AD:DP:GQ:PL 0/0:216,0:216:99:0,120,1800
GT:AD:DP:GQ:PL 0/0:216,0:216:99:0,120,1800
GT:AD:DP:GQ:PGT:PID:PL 0/1:185,232:417:99:0|1:8029494_T_G:8670,0,6429
GT:AD:DP:GQ:PL 0/0:367,0:367:99:0,120,1800
GT:AD:DP:GQ:PGT:PID:PL 0/1:150,198:348:99:0|1:8029494_T_G:7930,0,5677
GT:AD:DP:GQ:PGT:PID:PL 0/1:148,196:344:99:0|1:8029494_T_G:7876,0,5652
GT:AD:DP:GQ:PGT:PID:PL 0/0:148,0:344:99:0|1:8029494_T_G:7876,8334,14591
GT:AD:DP:GQ:PGT:PID:PL 0/0:148,0:344:99:0|1:8029494_T_G:7876,8334,14591
FORMAT 列指定在以下列中以:"分隔的字段的 ID.
The FORMAT column specifies the IDs for the fields that are given in the following column splitted by ":".
我想根据 FORMAT 列中的 ID/位置从第二列中提取特定字段，即 AD(第 2 位)、DP(第 3 位)或 GQ(第 4 位).
I would like to extract specific fields from the second column based on the ID/position from the FORMAT column, i.e. AD (2nd), DP (3rd) or GQ (4th).
我能够使用以下代码提取 AD 字段:
I was able to extract the AD field with the following code:
SELECT SUBSTRING(Sample, CHARINDEX(':',Sample)+1, CHARINDEX(':',Sample,5)-5) FROM Table 1;
问题是我无法提取字段 DP 或 GQ，因为不同字段的长度并不总是相同的，我无法指定哪个应该是搜索以下:"的起始位置位置.
The problem is that I am not able to extract the fields DP or GQ, since the length of the different fields is not always the same one and I cannot specify which should be the starting position to search for the following ":" location.
我也尝试使用本网站的拆分功能:
I also tried to use the Split function from this website:
http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=50648
问题是我不知道如何将列声明为变量，以便我可以为表格的每一行提取所需的字段.
The problem is that I do not know how to declare a column as a variable so that I can extract the required field for every single row of the table.
[Sample] 列的所需输出应如下所示:
The desired output for the [Sample] column should look like this:
GT AD DP GQ
0/0 233,0 233 99
0/1 101,61 220 99
0/0 172,0 172 99
0/0 216,0 216 99
0/0 216,0 216 99
0/1 185,232 417 99
0/0 367,0 367 99
0/1 150,198 348 99
0/1 148,196 344 99
0/0 148,0 344 99
0/0 148,0 344 99
任何帮助将不胜感激，
谢谢，
推荐答案
也许有点 XML 作为解析器
Perhaps a little XML as the parser
示例
Select A.Format
,B.*
From YourTable A
Cross Apply (
Select Pos2 = ltrim(rtrim(xDim.value('/x[2]','varchar(max)')))
,Pos3 = ltrim(rtrim(xDim.value('/x[3]','varchar(max)')))
,Pos4 = ltrim(rtrim(xDim.value('/x[4]','varchar(max)')))
From (Select Cast('<x>' + replace((Select replace(A.Format,':','§§Split§§') as [*] For XML Path('')),'§§Split§§','</x><x>')+'</x>' as xml) as xDim) as A
) B
退货
Format Pos2 Pos3 Pos4
GT:AD:DP:GQ:PL AD DP GQ
GT:AD:DP:GQ:PL AD DP GQ
GT:AD:DP:GQ:PL AD DP GQ
GT:AD:DP:GQ:PL AD DP GQ
GT:AD:DP:GQ:PL AD DP GQ
GT:AD:DP:GQ:PGT:PID:PL AD DP GQ
GT:AD:DP:GQ:PL AD DP GQ
GT:AD:DP:GQ:PGT:PID:PL AD DP GQ
GT:AD:DP:GQ:PGT:PID:PL AD DP GQ
GT:AD:DP:GQ:PGT:PID:PL AD DP GQ
GT:AD:DP:GQ:PGT:PID:PL AD DP GQ
或简单版本
Select A.Format
,Pos2 = Cast('<x>' + replace(Format,':','</x><x>')+'</x>' as xml).value('/x[2]','varchar(max)')
,Pos3 = Cast('<x>' + replace(Format,':','</x><x>')+'</x>' as xml).value('/x[3]','varchar(max)')
,Pos4 = Cast('<x>' + replace(Format,':','</x><x>')+'</x>' as xml).value('/x[4]','varchar(max)')
From YourTable A
或者如果对 UDF 开放
看一看 TSQL/SQL Server - 将分隔字符串解析/拆分为多个/单独列的表函数
编辑 - 示例更新
Select A.Format
,GT = Cast('<x>' + replace(Sample,':','</x><x>')+'</x>' as xml).value('/x[1]','varchar(max)')
,AD = Cast('<x>' + replace(Sample,':','</x><x>')+'</x>' as xml).value('/x[2]','varchar(max)')
,DP = Cast('<x>' + replace(Sample,':','</x><x>')+'</x>' as xml).value('/x[3]','varchar(max)')
,GQ = Cast('<x>' + replace(Sample,':','</x><x>')+'</x>' as xml).value('/x[4]','varchar(max)')
From YourTable A
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