SQLSERVER2008 解析JSON函数
时间:2021-08-11
本文章向大家介绍SQLSERVER2008 解析JSON函数，主要包括SQLSERVER2008 解析JSON函数使用实例、应用技巧、基本知识点总结和需要注意事项，具有一定的参考价值，需要的朋友可以参考一下。
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(max) ,--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) 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 @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 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 ,
@SequenceNo = @SequenceNo + 1
SELECT @end = CHARINDEX(',', @contents)-- a string-token, object-token, list-token, number,boolean, or null
IF @end = 0
BEGIN
SELECT @end = PATINDEX('%[A-Za-z0-9@+.e][^A-Za-z0-9@+.e]%',
@Contents + ' ' COLLATE SQL_Latin1_General_CP850_Bin)
+ 1
END
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
( 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
原文地址：https://www.cnblogs.com/YoungHeart/p/15128899.html
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