SQL SERVER Json 解析方法
阿新 • • 發佈：2018-11-15
整理記錄一個Json解析的函式方法，方法如下：
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(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 @ 有如下的Json資料：
{
"status": 0,
"msg": "SUCCESS",
"data": [{
"id": 1,
"name": "xiaohong"
}, {
"id": 2,
"name": "xiaoming"
}]
}測試資料如下：
--測試資料
if not object_id(N'Tempdb..#T') is null
drop table #T
Go
Create table #T([JsonStr] nvarchar(200))
Insert #T
select N'{"status":0,"msg":"SUCCESS","data":[{"id":1,"name":"xiaohong"},{"id":2,"name":"xiaoming"}]}'
Go
--測試資料結束讀取資料：
Select b.* from #T CROSS APPLY dbo.parseJSON(JsonStr) AS b
我們看到資料已經解析出來了，可以根據需要讀取自己想要的資料了。
方法來源：論壇問題