我用C#3.5不具有使用第三方库的灵活性的平台上削减版本的工作。
虽然我可以解析JSON(使用JSON流阅读器),我不知道如何真正把它变成一个类。 (也有通常的JSON没有访问类解串器)。
有谁知道如何使用反射来手动(尚未动态)将一个JSON字符串成一个类?
样品JSON:
{"items":[ {"firstName":"bob", "lastName":"smith", "id":1001, "foods": [{"name":"fish", "name":"bacon", "name":"cereal"}]}, {"firstName":"sarah", "lastName":"smith", "id":1002, "foods": [{"name":"bacon", "name":"apples", "name":"chocolate"}]}, {"firstName":"tom", "lastName":"waffle", "id":1003, "foods": [{"name":"waffles", "name":"sticks", "name":"stones"}]}, {"firstName":"reginald", "lastName":"hamtuft", "id":1003, "foods": [{"name":"ham", "name":"cigars", "name":"noisy children"}]} ]}
好吧,我根据反馈重做我的答案。 动态对象生成的代码仍然来源于此:
反序列化JSON成C#动态对象?
这使用正则表达式,通用集合和它不使用Linq,但仅在2行和那些可以很容易地改写为不能使用的LINQ(在末尾的两个“结果=”线DynamicJsonObject.TryGetMember()
通用字典也可以用哈希表,如果有必要更换。
该JSON解析器是从适合我怎么可以反序列化JSON到一个简单的词典<字符串,字符串>在ASP.NET?
class Program
{
static void Main(string[] args)
{
string data = "{ 'test': 42, 'test2': 'test2\"', 'structure' : { 'field1': 'field1', 'field2': 44 } }";
dynamic x = new DynamicJsonObject(JsonMaker.ParseJSON(data));
Console.WriteLine(x.test2);
Console.WriteLine(x.structure.field1);
Console.ReadLine();
}
}
public class DynamicJsonObject : DynamicObject
{
private readonly IDictionary<string, object> _dictionary;
public DynamicJsonObject(IDictionary<string, object> dictionary)
{
if (dictionary == null)
throw new ArgumentNullException("dictionary");
_dictionary = dictionary;
}
public override string ToString()
{
var sb = new StringBuilder();
ToString(sb);
return sb.ToString();
}
private void ToString(StringBuilder sb)
{
sb.Append("{");
var firstInDictionary = true;
foreach (var pair in _dictionary)
{
if (!firstInDictionary)
sb.Append(",");
firstInDictionary = false;
var value = pair.Value;
var name = pair.Key;
if (value is string)
{
sb.AppendFormat("\"{0}\":\"{1}\"", name, value);
}
else if (value is IDictionary<string, object>)
{
sb.AppendFormat("\"{0}\":", name);
new DynamicJsonObject((IDictionary<string, object>)value).ToString(sb);
}
else if (value is ArrayList)
{
sb.Append("\"");
sb.Append(name);
sb.Append("\":[");
var firstInArray = true;
foreach (var arrayValue in (ArrayList)value)
{
if (!firstInArray)
sb.Append(",");
firstInArray = false;
if (arrayValue is IDictionary<string, object>)
new DynamicJsonObject((IDictionary<string, object>)arrayValue).ToString(sb);
else if (arrayValue is string)
sb.AppendFormat("\"{0}\"", arrayValue);
else
sb.AppendFormat("{0}", arrayValue);
}
sb.Append("]");
}
else
{
sb.AppendFormat("\"{0}\":{1}", name, value);
}
}
sb.Append("}");
}
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
if (!_dictionary.TryGetValue(binder.Name, out result))
{
// return null to avoid exception. caller can check for null this way...
result = null;
return true;
}
var dictionary = result as IDictionary<string, object>;
if (dictionary != null)
{
result = new DynamicJsonObject(dictionary);
return true;
}
var arrayList = result as ArrayList;
if (arrayList != null && arrayList.Count > 0)
{
if (arrayList[0] is IDictionary<string, object>)
result = new List<object>(arrayList.Cast<IDictionary<string, object>>().Select(x => new DynamicJsonObject(x)));
else
result = new List<object>(arrayList.Cast<object>());
}
return true;
}
}
public static class JsonMaker
{
public static Dictionary<string, object> ParseJSON(string json)
{
int end;
return ParseJSON(json, 0, out end);
}
private static Dictionary<string, object> ParseJSON(string json, int start, out int end)
{
Dictionary<string, object> dict = new Dictionary<string, object>();
bool escbegin = false;
bool escend = false;
bool inquotes = false;
string key = null;
int cend;
StringBuilder sb = new StringBuilder();
Dictionary<string, object> child = null;
List<object> arraylist = null;
Regex regex = new Regex(@"\\u([0-9a-z]{4})", RegexOptions.IgnoreCase);
int autoKey = 0;
bool inSingleQuotes = false;
bool inDoubleQuotes = false;
for (int i = start; i < json.Length; i++)
{
char c = json[i];
if (c == '\\') escbegin = !escbegin;
if (!escbegin)
{
if (c == '"' && !inSingleQuotes)
{
inDoubleQuotes = !inDoubleQuotes;
inquotes = !inquotes;
if (!inquotes && arraylist != null)
{
arraylist.Add(DecodeString(regex, sb.ToString()));
sb.Length = 0;
}
continue;
}
else if (c == '\'' && !inDoubleQuotes)
{
inSingleQuotes = !inSingleQuotes;
inquotes = !inquotes;
if (!inquotes && arraylist != null)
{
arraylist.Add(DecodeString(regex, sb.ToString()));
sb.Length = 0;
}
continue;
}
if (!inquotes)
{
switch (c)
{
case '{':
if (i != start)
{
child = ParseJSON(json, i, out cend);
if (arraylist != null) arraylist.Add(child);
else
{
dict.Add(key.Trim(), child);
key = null;
}
i = cend;
}
continue;
case '}':
end = i;
if (key != null)
{
if (arraylist != null) dict.Add(key.Trim(), arraylist);
else dict.Add(key.Trim(), DecodeString(regex, sb.ToString().Trim()));
}
return dict;
case '[':
arraylist = new List<object>();
continue;
case ']':
if (key == null)
{
key = "array" + autoKey.ToString();
autoKey++;
}
if (arraylist != null && sb.Length > 0)
{
arraylist.Add(sb.ToString());
sb.Length = 0;
}
dict.Add(key.Trim(), arraylist);
arraylist = null;
key = null;
continue;
case ',':
if (arraylist == null && key != null)
{
dict.Add(key.Trim(), DecodeString(regex, sb.ToString().Trim()));
key = null;
sb.Length = 0;
}
if (arraylist != null && sb.Length > 0)
{
arraylist.Add(sb.ToString());
sb.Length = 0;
}
continue;
case ':':
key = DecodeString(regex, sb.ToString());
sb.Length = 0;
continue;
}
}
}
sb.Append(c);
if (escend) escbegin = false;
if (escbegin) escend = true;
else escend = false;
}
end = json.Length - 1;
return dict; //theoretically shouldn't ever get here
}
private static string DecodeString(Regex regex, string str)
{
return Regex.Unescape(regex.Replace(str, match => char.ConvertFromUtf32(Int32.Parse(match.Groups[1].Value, System.Globalization.NumberStyles.HexNumber))));
}
}
感谢皮特和休息让我在正确的轨道此上。 在我来说,我也有一个JSON字符串反序列化到SQL CLR函数一个强类型的对象,所以我对我可以使用“安全”(库限制更多的信息在这里 )。
我修改为ParseJSON的代码 ,这反序列化到一个Dictionary<string, object>
以能够反序列化阵列,它不能这样做的阵列,我还开发了一些方法,以铸造所得的字典到强类型对象,而无需使用该JavaScriptConverter
或System.Runtime.Serialization
库,使用此代码,我们能做到以下几点:
//we have a foo and bar classes with a variety of fields and properties
private class foo
{
public List<double[][]> data;
public IEnumerable<object> DataObj;
public int integerField;
public long longProperty { get; set; }
public string stringValue;
public int? nullableInt;
public DateTime dateTimeValue;
public List<bar> classValues;
}
private class bar
{
public string stringValue;
public DateTimeOffset dateTimeOffsetValue;
}
static void Main(string[] args)
{
//lets deserialize the following JSON string into our foo object,
//the dictionary is optional, and not necessary if our JSON property names are the same as in our object.
//in this case it's used to map the "jdata" property on the JSON string to the "data" property of our object,
//in the case of the "dataObj", we are mapping to the uppercase field of our object
string JSONstring = "{\"jdata\":[[[1526518800000,7.0],[1526518834200,7.0]],[[1526549272200,25.0],[1526549306400,25.0]]],\"dataObj\":[[[1526518800000,7.0],[1526518834200,7.0]],\"abc\",123],\"integerField\":623,\"longProperty\":456789,\"stringValue\":\"foo\",\"nullableInt\":\"\",\"dateTimeValue\":\"2018-05-17T01:00:00.0000000\", \"classValues\": [{\"stringValue\":\"test\",\"dateTimeOffsetValue\":\"2018-05-17T05:00:00.0000000\"},{\"stringValue\":\"test2\",\"dateTimeOffsetValue\":\"2018-05-17T06:00:00.0000000\"}]}";
var mappingDict = new Dictionary<string, string>() { { "jdata", "data" }, { "dataObj", "DataObj" } };
foo myObject = ParseJSON<foo>(JSONstring, mappingDict);
}
该ParseJSON方法将采取JSON字符串作为输入和任选的Dictionary<string, string>
并试图将其铸入类型T
字典用于在JSON串中的任何属性映射到对象的属性(例如中,“jdata” /“数据”字典上面定义)。
public static T ParseJSON<T>(string jsonString, Dictionary<string, string> mappingTable = null)
{
Dictionary<string, object> jsonDictionary = ParseJSON(jsonString);
T castedObj = CastAs<T>(jsonDictionary, mappingTable);
return castedObj;
}
以下是我为JSON解析改性方法(可以解析数组的数组):
public static Dictionary<string, object> ParseJSON(string json)
{
int end;
return ParseJSON(json, 0, out end);
}
private static Dictionary<string, object> ParseJSON(string json, int start, out int end)
{
Dictionary<string, object> dict = new Dictionary<string, object>();
bool escbegin = false;
bool escend = false;
bool inquotes = false;
string key = null;
int cend;
StringBuilder sb = new StringBuilder();
Dictionary<string, object> child = null;
List<object> arraylist = null;
Regex regex = new Regex(@"\\u([0-9a-z]{4})", RegexOptions.IgnoreCase);
int autoKey = 0;
int subArrayCount = 0;
List<int> arrayIndexes = new List<int>();
bool inSingleQuotes = false;
bool inDoubleQuotes = false;
for (int i = start; i < json.Length; i++)
{
char c = json[i];
if (c == '\\') escbegin = !escbegin;
if (!escbegin)
{
if (c == '"' && !inSingleQuotes)
{
inDoubleQuotes = !inDoubleQuotes;
inquotes = !inquotes;
if (!inquotes && arraylist != null)
{
arraylist.Add(DecodeString(regex, sb.ToString()));
sb.Length = 0;
}
continue;
}
else if (c == '\'' && !inDoubleQuotes)
{
inSingleQuotes = !inSingleQuotes;
inquotes = !inquotes;
if (!inquotes && arraylist != null)
{
arraylist.Add(DecodeString(regex, sb.ToString()));
sb.Length = 0;
}
continue;
}
if (!inquotes)
{
switch (c)
{
case '{':
if (i != start)
{
child = ParseJSON(json, i, out cend);
if (arraylist != null)
{
arraylist.Add(child);
}
else
{
dict.Add(key.Trim(), child);
key = null;
}
i = cend;
}
continue;
case '}':
end = i;
if (key != null)
{
if (arraylist != null) dict.Add(key.Trim(), arraylist);
else dict.Add(key.Trim(), DecodeString(regex, sb.ToString().Trim()));
}
return dict;
case '[':
if (arraylist != null)
{
List<object> _tempArrayList = arraylist;
for (int l = 0; l < subArrayCount; l++)
{
if (l == subArrayCount - 1)
{
_tempArrayList.Add(new List<object>());
}
else
{
_tempArrayList = (List<object>)_tempArrayList[arrayIndexes[l]];
}
}
if (arrayIndexes.Count < subArrayCount)
{
arrayIndexes.Add(0);
}
subArrayCount++;
}
else
{
arraylist = new List<object>();
subArrayCount++;
}
continue;
case ']':
if (key == null)
{
key = "array" + autoKey.ToString();
autoKey++;
}
if (arraylist != null)
{
List<object> _tempArrayList = arraylist;
for (int l = 0; l < subArrayCount; l++)
{
if (l == subArrayCount - 1)
{
if (sb.Length > 0)
{
_tempArrayList.Add(sb.ToString());
}
subArrayCount--;
if (subArrayCount == arrayIndexes.Count)
{
if (arrayIndexes.Count > 0)
{
arrayIndexes[arrayIndexes.Count - 1]++;
}
}
else if (subArrayCount == arrayIndexes.Count - 1)
{
arrayIndexes.RemoveAt(arrayIndexes.Count - 1);
if (arrayIndexes.Count > 0)
{
arrayIndexes[arrayIndexes.Count - 1]++;
}
}
}
else
{
_tempArrayList = (List<object>)_tempArrayList[arrayIndexes[l]];
}
}
sb.Length = 0;
}
if (subArrayCount == 0)
{
dict.Add(key.Trim(), arraylist);
arraylist = null;
key = null;
}
continue;
case ',':
if (arraylist == null && key != null)
{
dict.Add(key.Trim(), DecodeString(regex, sb.ToString().Trim()));
key = null;
sb.Length = 0;
}
if (arraylist != null && sb.Length > 0)
{
List<object> _tempArrayList = arraylist;
for (int l = 0; l < subArrayCount; l++)
{
if (l == subArrayCount - 1)
{
_tempArrayList.Add(sb.ToString());
}
else
{
_tempArrayList = (List<object>)_tempArrayList[arrayIndexes[l]];
}
}
sb.Length = 0;
}
continue;
case ':':
key = DecodeString(regex, sb.ToString());
sb.Length = 0;
continue;
}
}
}
sb.Append(c);
if (escend) escbegin = false;
if (escbegin) escend = true;
else escend = false;
}
end = json.Length - 1;
return dict; //shouldn't ever get here unless the JSON is malformed
}
private static string DecodeString(Regex regex, string str)
{
return Regex.Unescape(regex.Replace(str, match => char.ConvertFromUtf32(Int32.Parse(match.Groups[1].Value, System.Globalization.NumberStyles.HexNumber))));
}
以下方法尝试转换返回的字典中从以前的方法注入了强劲的类型的对象,我所知道的是漫长的,但它的工作:
private static T CastAs<T>(Dictionary<string, object> source, Dictionary<string, string> mappingTable = null)
{
T outputData = (T)Activator.CreateInstance(typeof(T));
TrySet(outputData, source, mappingTable);
return outputData;
}
private static void TrySet(object target, Dictionary<string, object> source, Dictionary<string, string> mappingTable = null)
{
if (target == null)
{
throw new ArgumentNullException("target");
}
bool useMappingTable = mappingTable != null && mappingTable.Count > 0;
foreach (KeyValuePair<string, object> kv in source)
{
string propertyName = null;
if (useMappingTable && mappingTable.ContainsKey(kv.Key))
{
propertyName = mappingTable[kv.Key];
}
else
{
propertyName = kv.Key;
}
if (!string.IsNullOrEmpty(propertyName))
{
UpdateMember(target, propertyName, kv.Value, mappingTable);
}
}
}
private static void UpdateMember(object target, string propertyName, object value, Dictionary<string, string> mappingTable)
{
try
{
FieldInfo fieldInfo = target.GetType().GetField(propertyName);
if (fieldInfo != null)
{
value = ConvertTo(value, fieldInfo.FieldType, mappingTable);
fieldInfo.SetValue(target, value);
}
else
{
PropertyInfo propInfo = target.GetType().GetProperty(propertyName);
if (propInfo != null)
{
value = ConvertTo(value, propInfo.PropertyType, mappingTable);
propInfo.SetValue(target, value);
}
}
}
catch (Exception ex)
{
throw ex;
}
}
private static object ConvertTo(object value, Type targetType, Dictionary<string, string> mappingTable)
{
try
{
bool isNullable = false;
Type sourceType = value.GetType();
//Obtain actual type to convert to (this is necessary in case of Nullable types)
if (targetType.IsGenericType && targetType.GetGenericTypeDefinition() == typeof(Nullable<>))
{
isNullable = true;
targetType = targetType.GetGenericArguments()[0];
}
if (isNullable && string.IsNullOrWhiteSpace(Convert.ToString(value)))
{
return null;
}
//if we are converting from a dictionary to a class, call the TrySet method to convert its members
else if (targetType.IsClass && sourceType.IsGenericType && sourceType.GetGenericTypeDefinition() == typeof(Dictionary<,>))
{
//make sure our value is actually a Dictionary<string, object> in order to be able to cast
if (sourceType.GetGenericArguments()[0] == typeof(string))
{
object convertedValue = Activator.CreateInstance(targetType);
TrySet(convertedValue, (Dictionary<string, object>)value, mappingTable);
return convertedValue;
}
return null;
}
else if (IsCollection(value))
{
Type elementType = GetCollectionElementType(targetType);
if (elementType != null)
{
if (targetType.BaseType == typeof(Array))
{
return ConvertToArray(elementType, value, mappingTable);
}
else
{
return ConvertToList(elementType, value, mappingTable);
}
}
else
{
throw new NullReferenceException();
}
}
else if (targetType == typeof(DateTimeOffset))
{
return new DateTimeOffset((DateTime)ChangeType(value, typeof(DateTime)));
}
else if (targetType == typeof(object))
{
return value;
}
else
{
return ChangeType(value, targetType);
}
}
catch (Exception ex)
{
if (targetType.IsValueType)
{
return Activator.CreateInstance(targetType);
}
return null;
}
}
private static Array ConvertToArray(Type elementType, object value, Dictionary<string, string> mappingTable)
{
Array collection = Array.CreateInstance(elementType, ((ICollection)value).Count);
int i = 0;
foreach (object item in (IEnumerable)value)
{
try
{
collection.SetValue(ConvertTo(item, elementType, mappingTable), i);
i++;
}
catch (Exception ex)
{
//nothing here, just skip the item
}
}
return collection;
}
private static IList ConvertToList(Type elementType, object value, Dictionary<string, string> mappingTable)
{
Type listType = typeof(List<>);
Type constructedListType = listType.MakeGenericType(elementType);
IList collection = (IList)Activator.CreateInstance(constructedListType);
foreach (object item in (IEnumerable)value)
{
try
{
collection.Add(ConvertTo(item, elementType, mappingTable));
}
catch (Exception ex)
{
//nothing here, just skip the item
}
}
return collection;
}
private static bool IsCollection(object obj)
{
bool isCollection = false;
Type objType = obj.GetType();
if (!typeof(string).IsAssignableFrom(objType) && typeof(IEnumerable).IsAssignableFrom(objType))
{
isCollection = true;
}
return isCollection;
}
private static Type GetCollectionElementType(Type objType)
{
Type elementType;
Type[] genericArgs = objType.GenericTypeArguments;
if (genericArgs.Length > 0)
{
elementType = genericArgs[0];
}
else
{
elementType = objType.GetElementType();
}
return elementType;
}
private static object ChangeType(object value, Type castTo)
{
try
{
return Convert.ChangeType(value, castTo);
}
catch (Exception ex)
{
//if the conversion failed, just return the original value
return value;
}
}
我希望这是有帮助的人仍然在寻找一种方式来做到这一点。
再次感谢皮特和其他人对他们的辉煌后。 我已经缠这是在询问JSON存储在关系表非常有用的一个SQL Server CLR标量函数矿(我知道有些人会说只使用MongoDB的!)。
请看下面:
public class JsonHelper
{
/// <summary>
/// Parses the JSON.
/// Thanks to http://stackoverflow.com/questions/14967618/deserialize-json-to-class-manually-with-reflection
/// </summary>
/// <param name="json">The json.</param>
/// <returns></returns>
public static Dictionary<string, object> DeserializeJson(string json)
{
int end;
return DeserializeJson(json, 0, out end);
}
/// <summary>
/// Parses the JSON.
/// </summary>
/// <param name="json">The json.</param>
/// <param name="start">The start.</param>
/// <param name="end">The end.</param>
/// <returns></returns>
private static Dictionary<string, object> DeserializeJson(string json, int start, out int end)
{
var dict = new Dictionary<string, object>();
var escbegin = false;
var escend = false;
var inquotes = false;
string key = null;
var sb = new StringBuilder();
List<object> arraylist = null;
var regex = new Regex(@"\\u([0-9a-z]{4})", RegexOptions.IgnoreCase);
var autoKey = 0;
var inSingleQuotes = false;
var inDoubleQuotes = false;
for (var i = start; i < json.Length; i++)
{
var c = json[i];
if (c == '\\') escbegin = !escbegin;
if (!escbegin)
{
if (c == '"' && !inSingleQuotes)
{
inDoubleQuotes = !inDoubleQuotes;
inquotes = !inquotes;
if (!inquotes && arraylist != null)
{
arraylist.Add(DecodeString(regex, sb.ToString()));
sb.Length = 0;
}
continue;
}
if (c == '\'' && !inDoubleQuotes)
{
inSingleQuotes = !inSingleQuotes;
inquotes = !inquotes;
if (!inquotes && arraylist != null)
{
arraylist.Add(DecodeString(regex, sb.ToString()));
sb.Length = 0;
}
continue;
}
if (!inquotes)
{
switch (c)
{
case '{':
if (i != start)
{
int cend;
var child = DeserializeJson(json, i, out cend);
if (arraylist != null)
{
arraylist.Add(child);
}
else
{
dict.Add(key.Trim(), child);
key = null;
}
i = cend;
}
continue;
case '}':
end = i;
if (key != null)
{
if (arraylist != null) dict.Add(key.Trim(), arraylist);
else dict.Add(key.Trim(), DecodeString(regex, sb.ToString().Trim()));
}
return dict;
case '[':
arraylist = new List<object>();
continue;
case ']':
if (key == null)
{
key = "array" + autoKey;
autoKey++;
}
if (arraylist != null && sb.Length > 0)
{
arraylist.Add(sb.ToString());
sb.Length = 0;
}
dict.Add(key.Trim(), arraylist);
arraylist = null;
key = null;
continue;
case ',':
if (arraylist == null && key != null)
{
dict.Add(key.Trim(), DecodeString(regex, sb.ToString().Trim()));
key = null;
sb.Length = 0;
}
if (arraylist != null && sb.Length > 0)
{
arraylist.Add(sb.ToString());
sb.Length = 0;
}
continue;
case ':':
key = DecodeString(regex, sb.ToString());
sb.Length = 0;
continue;
}
}
}
sb.Append(c);
if (escend) escbegin = false;
escend = escbegin;
}
end = json.Length - 1;
return dict; // theoretically shouldn't ever get here
}
/// <summary>
/// Decodes the string.
/// </summary>
/// <param name="regex">The regex.</param>
/// <param name="str">The STR.</param>
/// <returns></returns>
private static string DecodeString(Regex regex, string str)
{
return
Regex.Unescape(regex.Replace(str,
match =>
char.ConvertFromUtf32(Int32.Parse(match.Groups[1].Value,
System.Globalization.NumberStyles
.HexNumber))));
}
/// <summary>
/// Returns true if string has an "appearance" of being JSON-like
/// </summary>
/// <param name="input"></param>
/// <returns></returns>
public static bool IsJson(string input)
{
input = input.Trim();
return input.StartsWith("{") && input.EndsWith("}")
|| input.StartsWith("[") && input.EndsWith("]");
}
}
该CLR函数低于:
/// <summary>
/// Json "extractor" capable of extracting a value of a key using the object notation.
/// </summary>
/// <param name="json"></param>
/// <param name="key"></param>
/// <returns></returns>
[Microsoft.SqlServer.Server.SqlFunction]
public static SqlString fn_GetKeyValue(SqlString json, SqlString key)
{
var jsonString = json.ToString();
// Return if N/A
if (string.IsNullOrEmpty(jsonString) || !JsonHelper.IsJson(jsonString))
{
return json;
}
var keyString = key.ToString();
var jsonDictionary = JsonHelper.DeserializeJson(jsonString);
var lastNode = string.Empty;
foreach (var node in keyString.Split('.'))
{
if (!jsonDictionary.ContainsKey(node)) continue;
var childDictionary = jsonDictionary[node] as Dictionary<string, object>;
if (childDictionary != null)
{
jsonDictionary = childDictionary;
}
lastNode = node;
}
if (!jsonDictionary.ContainsKey(lastNode))
{
return null;
}
var keyValueString = jsonDictionary[lastNode].ToString();
return keyValueString == "null" ? null : new SqlString(keyValueString);
}
用法是:
-- Example 1 (querying a parent node)
SELECT dbo.fn_GetKeyValue('{
"ExchangeRates": {
"GBP": "1.2",
"USD": "2.0"
},
"Timestamp": "2015-04-10"
}', 'Timestamp');
-- Example 2 (querying a child node using a dot notation)
SELECT dbo.fn_GetKeyValue('{
"ExchangeRates": {
"GBP": "1.2",
"USD": "2.0"
},
"Timestamp": "2015-04-10"
}', 'ExchangeRates.GBP');