I have method to save all values from table to txt file:
UserDataDBsDataContext dataContext = new UserDataDBsDataContext();
List<UserData> usersL = (from u in dataContext.UserDatas
select u).ToList();
var properties = typeof(UserData).GetProperties();
var userValues = new List<string>();
foreach (var user in usersL)
{
var values = new List<object>();
foreach (var property in properties)
{
object value = property.GetValue(user, null);
values.Add(value);
}
userValues.Add(string.Join(",", values));
}
File.WriteAllLines("my_data.txt", userValues);
Now I have two query and I want to do exactly the same, so I tried to create separate method responsible for looping table values.
Loop Method:
public void loopProp(PropertyInfo[] properites, List<string> addedValues)
{
foreach (var qrl in ...........)
{
var values = new List<object>();
foreach (var property in properites)
{
object value = property.GetValue(qrl, null);
values.Add(value);
}
addedValues.Add(string.Join(",", values));
}
File.WriteAllLines("my_passed_data.txt", addedValues);
}
But I don't know, how to pass query result(ar or ud):
My code:
List<AutoRef> ar = (from a in rjdc.AutoRefs
select a).ToList();
List<UserDataRef> ud = (from u in rjdc.UserDataRefs
select u).ToList();
var propertiesAutoRef = typeof(AutoRef).GetProperties();
var autoValues = new List<string>();
var propertiesUserRef = typeof(UserDataRef).GetProperties();
var userValues = new List<string>();
//loopProp(propertiesAutoRef, autoValues);
//loopProp(propertiesUserRef, userValues);
Answering your concrete question. You should make the method generic and pass the source as IEnumerable<T>:
public void loopProp<T>(IEnumerable<T> source, PropertyInfo[] properites, List<string> addedValues)
{
foreach (var qrl in source)
{
// ...
}
File.WriteAllLines("my_passed_data.txt", addedValues);
}
Usage:
loopProp(ar, propertiesAutoRef, autoValues);
loopProp(ud, propertiesUserRef, userValues);
Probably you should pass the file path argument as well instead of hardcoding it inside the method.
Related
var orderJson = JsonConvert.DeserializeObject<dynamic>(httpResultStr);
var orderidCount = orderJson.data.orderUuids.Count;
for (int i = 0; i <= orderidCount; i++)
{
var orderId = orderJson.data.orderUuids[i]; // my fail attempt. Didnt work
var map = orderJson.data.ordersMap;
foreach (var d in map)
{
var receipt = d.fareInfo.totalPrice;
Console.WriteLine(receipt);
}
}
Im trying to access the ordersMap members with the given values in orderUuids object. Inside the ordersMap Ids contain the fareInfo.totalPrice property that I'm trying to access. How would I go about achieving this?
[![json tree with ordersMap. Trying to access its members with the given values in orderUuids object.][1]][1]
You can make a partial/full map using the JSON file and use JsonConvert.DeserializeObject<>(json).
Other solution could be create a partial map using an anonymous type. Here is a code snip.
var anonymousTypeObject = new
{
status = "",
data = new
{
ordersMap = new Dictionary<string, JToken>(),
orderUuids = new string[0]
}
};
var obj = JsonConvert.DeserializeAnonymousType(json, anonymousTypeObject);
foreach (var kvp in obj.data.ordersMap)
{
var totalPrice = kvp.Value["fareInfo"]?["totalPrice"]?.ToString();
Debug.WriteLine($"{kvp.Key} -> {totalPrice}");
}
EDIT If you don't want any map use this solution.
var jObj = JsonConvert.DeserializeObject<JObject>(json);
var orderUuids = jObj.SelectToken("data.orderUuids")?.Values<string>();
foreach (var orderUuid in orderUuids)
{
var totalPrice = jObj.SelectToken($"data.ordersMap.{orderUuid}.fareInfo.totalPrice")?.Value<double>();
Debug.WriteLine($"{orderUuid} -> {totalPrice}");
}
IEnumerable<WebsiteWebPage> data = GetWebPages();
foreach (var value in data)
{
if (value.WebPage.Contains(".htm"))
{
WebsiteWebPage pagesinfo = new WebsiteWebPage();
pagesinfo.WebPage = value.WebPage;
pagesinfo.WebsiteId = websiteid;
db.WebsiteWebPages.Add(pagesinfo);
}
}
db.SaveChanges();
I want to add only distinct values to database in above code. Kindly help me how to do it as I am not able to find any solution.
IEnumerable<WebsiteWebPage> data = GetWebPages();
foreach (var value in data)
{
if (value.WebPage.Contains(".htm"))
{
var a = db.WebsiteWebPages.Where(i => i.WebPage == value.WebPage.ToString()).ToList();
if (a.Count == 0)
{
WebsiteWebPage pagesinfo = new WebsiteWebPage();
pagesinfo.WebPage = value.WebPage;
pagesinfo.WebsiteId = websiteid;
db.WebsiteWebPages.Add(pagesinfo);
db.SaveChanges();
}
}
}
This is the code that I used to add distinct data.I hope it helps
In addition to the code sample Furkan Öztürk supplied, Make sure your DB has a constraint so that you cannot enter duplicate values in the column. Belt and braces approach.
I assume that by "distinct values" you mean "distinct value.WebPage values":
// get existing values (if you ever need this)
var existingWebPages = db.WebsiteWebPages.Select(v => v.WebPage);
// get your pages
var webPages = GetWebPages().Where(v => v.WebPage.Contains(".htm"));
// get distinct WebPage values except existing ones
var distinctWebPages = webPages.Select(v => v.WebPage).Distinct().Except(existingWebPages);
// create WebsiteWebPage objects
var websiteWebPages = distinctWebPages.Select(v =>
new WebsiteWebPage { WebPage = v, WebsiteId = websiteid});
// save all at once
db.WebsiteWebPages.AddRange(websiteWebPages);
db.SaveChanges();
Assuming that you need them to be unique by WebPage and WebSiteId
IEnumerable<WebsiteWebPage> data = GetWebPages();
foreach (var value in data)
{
if (value.WebPage.Contains(".htm"))
{
WebsiteWebPage pagesinfo = new WebsiteWebPage();
if (db.WebsiteWebPages.All(c=>c.WebPage != value.WebPage|| c.WebsiteId != websiteid))
{
pagesinfo.WebPage = value.WebPage;
pagesinfo.WebsiteId = websiteid;
db.WebsiteWebPages.Add(pagesinfo);
}
}
}
db.SaveChanges();
UPDATE
To optimize this (given that your table contains much more data than your current list), override your equals in WebsiteWebPage class to define your uniqueness criteria then:
var myWebsiteWebPages = data.select(x=> new WebsiteWebPage { WebPage = x.WebPage, WebsiteId = websiteid}).Distinct();
var duplicates = db.WebsiteWebPages.Where(x=> myWebsiteWebPage.Contains(x));
db.WebsiteWebPages.AddRange(myWebsiteWebPages.Where(x=> !duplicates.Contains(x)));
this is a one database query to retrieve ONLY duplicates and then removing them from the list
You can use the following code,
IEnumerable<WebsiteWebPage> data = GetWebPages();
var templist = new List<WebsiteWebPage>();
foreach (var value in data)
{
if (value.WebPage.Contains(".htm"))
{
WebsiteWebPage pagesinfo = new WebsiteWebPage();
pagesinfo.WebPage = value.WebPage;
pagesinfo.WebsiteId = websiteid;
templist.Add(pagesinfo);
}
}
var distinctList = templist.GroupBy(x => x.WebsiteId).Select(group => group.First()).ToList();
db.WebsiteWebPages.AddRange(distinctList);
db.SaveChanges();
Or you can use MoreLINQ here to filter distinct the list by parameter like,
var res = tempList.Distinct(x=>x.WebsiteId).ToList();
db.WebsiteWebPages.AddRange(res);
db.SaveChanges();
I have this query:
var smallExchangeReport = from ex in exchangeProgReport
where !string.IsNullOrEmpty(ex.comment)
group ex by new { ex.siteName } into g
select new SummuryReportTraffic
{
siteName = g.Key.siteName,
exchangeCounter = g.Where(x => x.Prog1ToProg2Check == 1).Count(),
descriptions = (from t in g
group t by new { t.comment, t.siteName } into grp
select new Description
{
title = grp.Key.comment,
numbers = grp.Select(x => x.comment).Count()
})
};
At some point I put it to the dataTable using foreach loop:
foreach (var item in smallExchangeReport)
{
dr = smrTable.NewRow();
foreach (var d in item.descriptions)
{
dr[d.title] = d.numbers;
}
smrTable.Rows.Add(dr);
}
But I need to put the LINQ result to dataTable without using foreach loop.
So I made some changes to my code above according to this link:
DataTable dt = new DataTable();
DataRow dr = dt.NewRow();
IEnumerable<DataRow> smallExchangeReport = from ex in exchangeProgReport.AsEnumerable()
where !string.IsNullOrEmpty(ex.comment)
group ex by new { ex.siteName } into g
select new
{
siteName = g.Key.siteName,
exchangeCounter = g.Where(x => x.Prog1ToProg2Check == 1).Count(),
descriptions = (from t in g.AsEnumerable()
group t by new { t.comment, t.siteName } into grp
select new
{
title = grp.Key.comment,
numbers = grp.Select(x => x.comment).Count()
})
};
// Create a table from the query.
DataTable boundTable = smallExchangeReport.CopyToDataTable<DataRow>();
But on changed LINQ query I get this error:
Cannot implicitly convert type:'System.Collections.Generic.IEnumerable<<anonymous type: string siteName, int exchangeCounter>>' to
'System.Collections.Generic.IEnumerable<System.Data.DataRow>'. An explicit conversion exists (are you missing a cast?)
My question is how to cast the query to make it work?I tryed to cast to(DataRow) the result of the LINQ but it didn't worked.
In your LINQ query, you are trying to get IEnumerable<DataRow> as the result, but actually you select new objects of an anonymous type: select new { siteName = .... }. This cannot work because your anonymous type cannot be cast to DataRow.
What you need to do is use a function that would populate a DataRow like this:
DataRow PopulateDataRow(
DataTable table,
string siteName,
int exchangeCounter,
IEnumerable<Description> descriptions
{
var dr = table.NewRow();
// populate siteName and exchangeCounter
// (not sure how your data row is structured, so I leave it to you)
foreach (var d in descriptions)
{
dr[d.title] = d.numbers;
}
return dr;
}
then in your LINQ query, use it as follows:
IEnumerable<DataRow> smallExchangeReport =
from ex in exchangeProgReport.AsEnumerable()
where !string.IsNullOrEmpty(ex.comment)
group ex by new { ex.siteName } into g
select PopulateDataRow(
smrTable,
siteName: g.Key.siteName,
exchangeCounter: g.Where(x => x.Prog1ToProg2Check == 1).Count(),
descriptions: (from t in g.AsEnumerable()
group t by new { t.comment, t.siteName } into grp
select new Description {
title = grp.Key.comment,
numbers = grp.Select(x => x.comment).Count()
}
)
);
This solution gets rid of one foreach (on rows) and leaves the other one (on descriptions).
If removing the second foreach is important... I would still leave it inside PopulateDataRow. I don't see an elegant way to remove it. You can call a method from LINQ query which reads like a deterministic function, but actually creates the side effect of setting a column value on a data row, but it doesn't feel right to me.
this is can help you.
defining table structure.
DataTable tbl = new DataTable();
tbl.Columns.Add("Id");
tbl.Columns.Add("Name");
and we need to create datarow from anonymous type.
Func<object, DataRow> createRow = (object data) =>
{
var row = tbl.NewRow();
row.ItemArray = data.GetType().GetProperties().Select(a => a.GetValue(data)).ToArray();
return row;
};
test with fake query:
var enumarate = Enumerable.Range(0, 10);
var rows = from i in enumarate
select createRow( new { Id = i, Name = Guid.NewGuid().ToString() });
var dataTable = rows.CopyToDataTable<DataRow>();
You can use this method:
private DataTable ListToDataTable<T>(List<T> objs, string tableName) {
var table = new DataTable(tableName);
var lists = new List<List<object>>();
// init columns
var propertyInfos = new List<PropertyInfo>();
foreach (var propertyInfo in typeof(T).GetProperties()) {
propertyInfos.Add(propertyInfo);
if(propertyInfo.PropertyType.IsEnum || propertyInfo.PropertyType.IsNullableEnum()) {
table.Columns.Add(propertyInfo.Name, typeof(int));
} else {
table.Columns.Add(propertyInfo.Name, Nullable.GetUnderlyingType(propertyInfo.PropertyType) ?? propertyInfo.PropertyType);
}
table.Columns[table.Columns.Count - 1].AllowDBNull = true;
}
// fill rows
foreach(var obj in objs) {
var list = new List<object>();
foreach(var propertyInfo in propertyInfos) {
object currentValue;
if(propertyInfo.PropertyType.IsEnum || propertyInfo.PropertyType.IsNullableEnum()) {
var val = propertyInfo.GetValue(obj);
if(val == null) {
currentValue = DBNull.Value;
} else {
currentValue = (int)propertyInfo.GetValue(obj);
}
} else {
var val = propertyInfo.GetValue(obj);
currentValue = val ?? DBNull.Value;
}
list.Add(currentValue);
}
lists.Add(list);
}
lists.ForEach(x => table.Rows.Add(x.ToArray()));
return table;
}
Edit:
this extension method is used:
public static bool IsNullableEnum(this Type t) {
var u = Nullable.GetUnderlyingType(t);
return u != null && u.IsEnum;
}
I need to write search based on following criteria:
I need to find all records that match values of
key1 OR key2 OR key 3 values...etc
The number of keys and values is variable
List<KeyValuePair<string, string[]>> filterlist = new List<KeyValuePair<string, string[]>>()
{
new KeyValuePair<string, string[]>("Key1", new []{"jay","bloggs"}),
new KeyValuePair<string, string[]>("Key2", new []{"joe","blog","doe"}),
new KeyValuePair<string, string[]>("Key3", new []{"jon","blog"}),
};
Now my implementation
My current implementation does search but all expressions are "AND" instead of OR. I am not sure how to write it.
public class UserSearcher
{
private List<UserProfile> userProfiles;
public UserSearcher()
{
userProfiles = new List<UserProfile>();
}
public static List<UserProfile> SearchProfiles(List<KeyValuePair<string, string[]>> filterList)
{
var list = new List<UserProfile>();
var query = list.AsQueryable();
// search for each pair inside as or
foreach (KeyValuePair<string, string[]> searchPair in filterList)
{
foreach (string searchString in searchPair.Value)
{
string s = searchString;
// search for each item inside as and (has to contains all search strings
query = query.Where(x => x.PersonName.Contains(s));
}
}
return list = query.ToList();
}
}
The full example except db is:
https://gist.github.com/cpoDesign/acf69bc242ed0755597d
Use Predicate Builder - it works well.
So, if I got it right, you want to get back list of UserProfile where PersonName is inside any string[] of KeyValuePair list.
If so, try with this:
public static List<UserProfile> SearchProfiles(List<KeyValuePair<string, string[]>> filterList)
{
var list = new List<UserProfile>();
return list.Where(profile => filterList.Any(kvp => kvp.Value.Contains(profile.PersonName))).ToList();
}
Test example:
public static Expression<Func<T,bool>>
Or<T>(IEnumerable<Expression<Func<T,bool>>> expList){
ParameterExpression pe = Expression.Parameter(typeof(T));
Expression r = null;
foreach(var exp in expList){
r = r == null ? exp : Expression.Or(r,exp);
}
return Expression.Lambda<Func<T,bool>>(r.Body,pe);
}
var orList = new List<Expression<Func<T,bool>>>();
foreach (KeyValuePair<string, string[]> searchPair in filterList)
{
foreach (string searchString in searchPair.Value)
{
string s = searchString;
// search for each item inside as and
// (has to contains all search strings
orList.Add(x => x.PersonName.Contains(s));
}
}
query = query.Where( Or(expList));
I have an image site where users can tag photos much like you can tag a question on Stackoverflow.
I have the following tables:
Images [ID, URL, etc]
Tags [ID, TagName]
ImageTag [TagID, ImageID]
I want to write a method with the signature:
public void UpdateImageTags(int imageId, IEnumerable<string> currentTags)
This method will do the following:
Create any new Tags in currentTags that don't already exist in the Tags table.
Get the old ImageTag's for an image.
Delete any ImageTag's that no longer exist in the currentTags
Add any ImageTag's that are new between the currentTags and oldTags.
Here is my attempt at that method:
public void UpdateImageTags(int imageId, IEnumerable<string> currentTags)
{
using (var db = new ImagesDataContext())
{
var oldTags = db.ImageTags.Where(it => it.ImageId == imageId).Select(it => it.Tag.TagName);
var added = currentTags.Except(oldTags);
var removed = oldTags.Except(currentTags);
// Add any new tags that need created
foreach (var tag in added)
{
if (!db.Tags.Any(t => t.TagName == tag))
{
db.Tags.InsertOnSubmit(new Tag { TagName = tag });
}
}
db.SubmitChanges();
// Delete any ImageTags that need deleted.
var deletedImageTags = db.ImageTags.Where(it => removed.Contains(it.Tag.TagName));
db.ImageTags.DeleteAllOnSubmit(deletedImageTags);
// Add any ImageTags that need added.
var addedImageTags = db.Tags.Where(t => added.Contains(t.TagName)).Select(t => new ImageTag { ImageId = imageId, TagId = t.TagId });
db.ImageTags.InsertAllOnSubmit(addedImageTags);
db.SubmitChanges();
}
}
However, this fails on the line:
db.ImageTags.DeleteAllOnSubmit(deletedImageTags);
With the error:
Local sequence cannot be used in LINQ to SQL implementations of query
operators except the Contains operator.
Is there an easier way I can handle the operation of adding new tags, deleting old ImageTags, adding new ImageTags in LINQ to SQL?
Seems like this would be easiest
public void UpdateImageTags(int imageId, IEnumerable<string> currentTags)
{
using (var db = new ImagesDataContext())
{
var image = db.Images.Where(it => it.ImageId == imageId).First()
image.Tags.Clear();
foreach(string s in currentTags)
{
image.Tags.Add(new Tag() { TagName = s});
}
db.SubmitChanges();
}
}
This might have to be modified slightly for LinqtoSQL. EF is what i have been using most recently. Also this is dependent on Lazy loading being enabled. If it is not, you will have to force the include of the image tags.
Here is a helper method to deal with many-to-many relationships:
public static void UpdateReferences<FK, FKV>(
this EntitySet<FK> refs,
Expression<Func<FK, FKV>> fkexpr,
IEnumerable<FKV> values)
where FK : class
where FKV : class
{
Func<FK, FKV> fkvalue = fkexpr.Compile();
var fkmaker = MakeMaker(fkexpr);
var fkdelete = MakeDeleter(fkexpr);
var fks = refs.Select(fkvalue).ToList();
var added = values.Except(fks);
var removed = fks.Except(values);
foreach (var add in added)
{
refs.Add(fkmaker(add));
}
foreach (var r in removed)
{
var res = refs.Single(x => fkvalue(x) == r);
refs.Remove(res);
fkdelete(res);
}
}
static Func<FKV, FK> MakeMaker<FKV, FK>(Expression<Func<FK, FKV>> fkexpr)
{
var me = fkexpr.Body as MemberExpression;
var par = Expression.Parameter(typeof(FKV), "fkv");
var maker = Expression.Lambda(
Expression.MemberInit(Expression.New(typeof(FK)),
Expression.Bind(me.Member, par)), par);
var cmaker = maker.Compile() as Func<FKV, FK>;
return cmaker;
}
static Action<FK> MakeDeleter<FK, FKV>(Expression<Func<FK, FKV>> fkexpr)
{
var me = fkexpr.Body as MemberExpression;
var pi = me.Member as PropertyInfo;
var assoc = Attribute.GetCustomAttribute(pi, typeof(AssociationAttribute))
as AssociationAttribute;
if (assoc == null || !assoc.DeleteOnNull)
{
throw new ArgumentException("DeleteOnNull must be set to true");
}
var par = Expression.Parameter(typeof(FK), "fk");
var maker = Expression.Lambda(
Expression.Call(par, pi.GetSetMethod(),
Expression.Convert(Expression.Constant(null), typeof(FKV))), par);
var cmaker = maker.Compile() as Action<FK>;
return cmaker;
}
Usage:
IEnumerable<Tag> values = ...;
Image e = ...;
e.ImageTags.UpdateReferences(x => x.Tag, tags);