SSIS スクリプト タスクで DataContractJsonSerializer を使用して、MongoDB からの REST API 応答をシリアル化し、フィールドをストアド プロシージャに渡して SQL Server テーブルに入力しています。パフォーマンスは悪く、より堅牢なソリューションを見つけようとしています。
より高速で堅牢なソリューションを推奨できる人はいますか? 私は REST API の世界に不慣れで、JSON の経験は現時点ではかなり限られています。
同様のソリューションを紹介する JSON.Net エンドツーエンドの例はありますか?
ありがとうございました、
ウィル・ファデル
Mongo Export ユーティリティの使用を検討しましたか? Mongo データを CSV にエクスポートしてから、フラット ファイルをインポートできます。JSON ドキュメントを SQL Server で解析する必要がなくなると、パフォーマンスが大幅に向上する可能性があります。
JSON は SQL Server のネイティブ データ型ではないため、通常はデータを直接 XML にシリアル化するか、JSON を XML にシリアル化してから SQL Server で XML を細断処理します。
SQL Server で JSON を解析する場合、適切な解決策はありません。以下は、JSON を解析するために Web から取得したテーブル値関数の修正版です。小さいドキュメントでは機能しましたが、非常に大きなドキュメントには拡張できませんでした。最終的に、NewtonSoft .NET 拡張機能を使用して JSON から XML にシリアル化する方が、SQL Server でテキストを細断処理するよりも優れたパフォーマンスを発揮することがわかりました。
CREATE FUNCTION [Resource].[ParseJson] (@JSON NVARCHAR(MAX))
RETURNS @Hierarchy TABLE
(
ElementId INT IDENTITY(1, 1) NOT NULL, /* internal surrogate primary key gives the order of parsing and the list order */
ParentId INT,/* if the element has a parent then it is in this column. The document is the ultimate parent, so you can get the structure from recursing from the document */
ObjectId INT,/* each list or object has an object id. This ties all elements to a parent. Lists are treated as objects here */
ObjectName NVARCHAR(2000),/* the name of the object */
StringValue NVARCHAR(MAX) NOT NULL,/*the string representation of the value of the element. */
ValueType VARCHAR(10) NOT null /* the declared type of the value represented as a string in StringValue*/
)
AS
BEGIN
DECLARE
@FirstObject INT, --the index of the first open bracket found in the JSON string
@OpenDelimiter INT,--the index of the next open bracket found in the JSON string
@NextOpenDelimiter INT,--the index of subsequent open bracket found in the JSON string
@NextCloseDelimiter INT,--the index of subsequent close bracket found in the JSON string
@Type NVARCHAR(10),--whether it denotes an object or an array
@NextCloseDelimiterChar CHAR(1),--either a '}' or a ']'
@Contents NVARCHAR(MAX), --the unparsed contents of the bracketed expression
@Start INT, --index of the start of the token that you are parsing
@end INT,--index of the end of the token that you are parsing
@param INT,--the parameter at the end of the next Object/Array token
@EndOfName INT,--the index of the start of the parameter at end of Object/Array token
@token NVARCHAR(200),--either a string or object
@value NVARCHAR(MAX), -- the value as a string
@name NVARCHAR(200), --the name as a string
@ParentId INT,--the next parent ID to allocate
@lenJSON INT,--the current length of the JSON String
@characters NCHAR(36),--used to convert hex to decimal
@result BIGINT,--the value of the hex symbol being parsed
@index SMALLINT,--used for parsing the hex value
@Escape INT --the index of the next escape character
DECLARE @Strings TABLE /* in this temporary table we keep all strings, even the names of the elements, since they are 'escaped' in a different way, and may contain, unescaped, brackets denoting objects or lists. These are replaced in the JSON string by tokens representing the string */
(
String_ID INT IDENTITY(1, 1),
StringValue NVARCHAR(MAX)
)
SELECT--initialise the characters to convert hex to ascii
@characters='0123456789abcdefghijklmnopqrstuvwxyz',
/* firstly we process all strings. This is done because [{} and ] aren't escaped in strings, which complicates an iterative parse. */
@ParentId=0;
WHILE 1=1 --forever until there is nothing more to do
BEGIN
SELECT
@start=PATINDEX('%[^a-zA-Z]["]%', @json collate SQL_Latin1_General_CP850_Bin);--next delimited string
IF @start=0 BREAK --no more so drop through the WHILE loop
IF SUBSTRING(@json, @start+1, 1)='"'
BEGIN --Delimited Name
SET @start=@Start+1;
SET @end=PATINDEX('%[^\]["]%', RIGHT(@json, LEN(@json+'|')-@start) collate SQL_Latin1_General_CP850_Bin);
END
IF @end=0 --no end delimiter to last string
BREAK --no more
SELECT @token=SUBSTRING(@json, @start+1, @end-1)
--now put in the escaped control characters
SELECT @token=REPLACE(@token, FROMString, TOString)
FROM
(SELECT
'\"' AS FromString, '"' AS ToString
UNION ALL SELECT '\\', '\'
UNION ALL SELECT '\/', '/'
UNION ALL SELECT '\b', CHAR(08)
UNION ALL SELECT '\f', CHAR(12)
UNION ALL SELECT '\n', CHAR(10)
UNION ALL SELECT '\r', CHAR(13)
UNION ALL SELECT '\t', CHAR(09)
) substitutions
SELECT @result=0, @escape=1
--Begin to take out any hex escape codes
WHILE @escape>0
BEGIN
SELECT @index=0,
--find the next hex escape sequence
@escape=PATINDEX('%\x[0-9a-f][0-9a-f][0-9a-f][0-9a-f]%', @token collate SQL_Latin1_General_CP850_Bin)
IF @escape>0 --if there is one
BEGIN
WHILE @index<4 --there are always four digits to a \x sequence
BEGIN
SELECT --determine its value
@result=@result+POWER(16, @index)
*(CHARINDEX(SUBSTRING(@token, @escape+2+3-@index, 1),
@characters)-1), @index=@index+1 ;
END
-- and replace the hex sequence by its unicode value
SELECT @token=STUFF(@token, @escape, 6, NCHAR(@result))
END
END
--now store the string away
INSERT INTO @Strings (StringValue) SELECT @token
-- and replace the string with a token
SELECT @JSON=STUFF(@json, @start, @end+1,
'@string'+CONVERT(NVARCHAR(5), @@identity))
END
-- all strings are now removed. Now we find the first leaf.
WHILE 1=1 --forever until there is nothing more to do
BEGIN
SELECT @ParentId=@ParentId+1
--find the first object or list by looking for the open bracket
SELECT @FirstObject=PATINDEX('%[{[[]%', @json collate SQL_Latin1_General_CP850_Bin)--object or array
IF @FirstObject = 0 BREAK
IF (SUBSTRING(@json, @FirstObject, 1)='{')
SELECT @NextCloseDelimiterChar='}', @type='object'
ELSE
SELECT @NextCloseDelimiterChar=']', @type='array'
SELECT @OpenDelimiter=@firstObject
WHILE 1=1 --find the innermost object or list...
BEGIN
SELECT
@lenJSON=LEN(@JSON+'|')-1
--find the matching close-delimiter proceeding after the open-delimiter
SELECT
@NextCloseDelimiter=CHARINDEX(@NextCloseDelimiterChar, @json,
@OpenDelimiter+1)
--is there an intervening open-delimiter of either type
SELECT @NextOpenDelimiter=PATINDEX('%[{[[]%',
RIGHT(@json, @lenJSON-@OpenDelimiter)collate SQL_Latin1_General_CP850_Bin)--object
IF @NextOpenDelimiter=0
BREAK
SELECT @NextOpenDelimiter=@NextOpenDelimiter+@OpenDelimiter
IF @NextCloseDelimiter<@NextOpenDelimiter
BREAK
IF SUBSTRING(@json, @NextOpenDelimiter, 1)='{'
SELECT @NextCloseDelimiterChar='}', @type='object'
ELSE
SELECT @NextCloseDelimiterChar=']', @type='array'
SELECT @OpenDelimiter=@NextOpenDelimiter
END
---and parse out the list or name/value pairs
SELECT
@contents=SUBSTRING(@json, @OpenDelimiter+1,
@NextCloseDelimiter-@OpenDelimiter-1)
SELECT
@JSON=STUFF(@json, @OpenDelimiter,
@NextCloseDelimiter-@OpenDelimiter+1,
'@'+@type+CONVERT(NVARCHAR(5), @ParentId))
WHILE (PATINDEX('%[A-Za-z0-9@+.e]%', @contents collate SQL_Latin1_General_CP850_Bin))<>0
BEGIN
IF @Type='Object' --it will be a 0-n list containing a string followed by a string, number,boolean, or null
BEGIN
SELECT
@end=CHARINDEX(':', ' '+@contents)--if there is anything, it will be a string-based name.
SELECT @start=PATINDEX('%[^A-Za-z@][@]%', ' '+@contents collate SQL_Latin1_General_CP850_Bin)--AAAAAAAA
SELECT @token=SUBSTRING(' '+@contents, @start+1, @End-@Start-1),
@endofname=PATINDEX('%[0-9]%', @token collate SQL_Latin1_General_CP850_Bin),
@param=RIGHT(@token, LEN(@token)-@endofname+1)
SELECT
@token=LEFT(@token, @endofname-1),
@Contents=RIGHT(' '+@contents, LEN(' '+@contents+'|')-@end-1)
SELECT @name=stringvalue FROM @strings
WHERE string_id=@param --fetch the name
END
ELSE
SELECT @Name=null
SELECT
@end=CHARINDEX(',', @contents)-- a string-token, object-token, list-token, number,boolean, or null
IF @end=0
SELECT @end=PATINDEX('%[A-Za-z0-9@+.e][^A-Za-z0-9@+.e]%', @Contents+' ' collate SQL_Latin1_General_CP850_Bin)
+1
SELECT
@start=PATINDEX('%[^A-Za-z0-9@+.e][A-Za-z0-9@+.e]%', ' '+@contents collate SQL_Latin1_General_CP850_Bin)
--select @start,@end, LEN(@contents+'|'), @contents
SELECT
@Value=RTRIM(SUBSTRING(@contents, @start, @End-@Start)),
@Contents=RIGHT(@contents+' ', LEN(@contents+'|')-@end)
IF SUBSTRING(@value, 1, 7)='@object'
INSERT INTO @hierarchy
(ObjectName, ParentId, StringValue, ObjectId, ValueType)
SELECT @name, @ParentId, SUBSTRING(@value, 8, 5),
SUBSTRING(@value, 8, 5), 'object'
ELSE
IF SUBSTRING(@value, 1, 6)='@array'
INSERT INTO @hierarchy
(ObjectName, ParentId, StringValue, ObjectId, ValueType)
SELECT @name, @ParentId, SUBSTRING(@value, 7, 5),
SUBSTRING(@value, 7, 5), 'array'
ELSE
IF SUBSTRING(@value, 1, 7)='@string'
INSERT INTO @hierarchy
(ObjectName, ParentId, StringValue, ValueType)
SELECT @name, @ParentId, stringvalue, 'string'
FROM @strings
WHERE string_id=SUBSTRING(@value, 8, 5)
ELSE
IF @value IN ('true', 'false')
INSERT INTO @hierarchy
(ObjectName, ParentId, StringValue, ValueType)
SELECT @name, @ParentId, @value, 'boolean'
ELSE
IF @value='null'
INSERT INTO @hierarchy
(ObjectName, ParentId, StringValue, ValueType)
SELECT @name, @ParentId, @value, 'null'
ELSE
IF PATINDEX('%[^0-9]%', @value collate SQL_Latin1_General_CP850_Bin)>0
INSERT INTO @hierarchy
(ObjectName, ParentId, StringValue, ValueType)
SELECT @name, @ParentId, @value, 'real'
ELSE
INSERT INTO @hierarchy
(ObjectName, ParentId, StringValue, ValueType)
SELECT @name, @ParentId, @value, 'int'
END
END
INSERT INTO @hierarchy (ObjectName, ParentId, StringValue, ObjectId, ValueType)
SELECT '-', NULL, '', @ParentId-1, @type
--
RETURN
END