欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  数据库

[转]在SqlServer 中解析JSON数据

程序员文章站 2022-04-08 13:46:03
...

CREATE FUNCTION dbo . parseJSON ( @JSON NVARCHAR ( MAX )) RETURNS @hierarchy TABLE ( element_id INT IDENTITY ( 1 , 1 ) NOT NULL, /* internal surrogate primary key gives the order of parsing and the list order */ sequenceNo [int] NULL, /* t

CREATE FUNCTION dbo.parseJSON( @JSON NVARCHAR(MAX))

RETURNS @hierarchy TABLE

(

element_id INT IDENTITY(1, 1) NOT NULL, /* internal surrogate primary key gives the order of parsing and the list order */

sequenceNo [int] NULL, /* the place in the sequence for the element */

parent_ID 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 */

Object_ID INT,/* each list or object has an object id. This ties all elements to a parent. Lists are treated as objects here */

NAME 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

@SequenceNo int, -- the sequence number within a list

@name NVARCHAR(200), --the name as a string

@parent_ID 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',

@SequenceNo=0, --set the sequence no. to something sensible.

/* firstly we process all strings. This is done because [{} and ] aren't escaped in strings, which complicates an iterative parse. */

@parent_ID=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) collateSQL_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 collateSQL_Latin1_General_CP850_Bin)

IF @escape>0 --if there is one

BEGIN

WHILE @index4 --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 @parent_ID=@parent_ID+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), @parent_ID))

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

@SequenceNo=0,@end=CHARINDEX(':', ' '+@contents)--if there is anything, it will be a string-based name.

SELECT @start=PATINDEX('%[^A-Za-z@][@]%', ' '+@contents collateSQL_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,@SequenceNo=@SequenceNo+1

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+' ' collateSQL_Latin1_General_CP850_Bin)

+1

SELECT

@start=PATINDEX('%[^A-Za-z0-9@+.e][A-Za-z0-9@+.e]%', ' '+@contents collateSQL_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

(NAME, SequenceNo, parent_ID, StringValue, Object_ID, ValueType)

SELECT @name, @SequenceNo, @parent_ID, SUBSTRING(@value, 8, 5),

SUBSTRING(@value, 8, 5), 'object'

ELSE

IF SUBSTRING(@value, 1, 6)='@array'

INSERT INTO @hierarchy

(NAME, SequenceNo, parent_ID, StringValue, Object_ID, ValueType)

SELECT @name, @SequenceNo, @parent_ID, SUBSTRING(@value, 7, 5),

SUBSTRING(@value, 7, 5), 'array'

ELSE

IF SUBSTRING(@value, 1, 7)='@string'

INSERT INTO @hierarchy

(NAME, SequenceNo, parent_ID, StringValue, ValueType)

SELECT @name, @SequenceNo, @parent_ID, stringvalue, 'string'

FROM @strings

WHERE string_id=SUBSTRING(@value, 8, 5)

ELSE

IF @value IN ('true', 'false')

INSERT INTO @hierarchy

(NAME, SequenceNo, parent_ID, StringValue, ValueType)

SELECT @name, @SequenceNo, @parent_ID, @value, 'boolean'

ELSE

IF @value='null'

INSERT INTO @hierarchy

(NAME, SequenceNo, parent_ID, StringValue, ValueType)

SELECT @name, @SequenceNo, @parent_ID, @value, 'null'

ELSE

IF PATINDEX('%[^0-9]%', @value collate SQL_Latin1_General_CP850_Bin)>0

INSERT INTO @hierarchy

(NAME, SequenceNo, parent_ID, StringValue, ValueType)

SELECT @name, @SequenceNo, @parent_ID, @value, 'real'

ELSE

INSERT INTO @hierarchy

(NAME, SequenceNo, parent_ID, StringValue, ValueType)

SELECT @name, @SequenceNo, @parent_ID, @value, 'int'

if @Contents=' ' Select @SequenceNo=0

END

END

INSERT INTO @hierarchy (NAME, SequenceNo, parent_ID, StringValue, Object_ID, ValueType)

SELECT '-',1, NULL, '', @parent_id-1, @type

--

RETURN

END

GO