For an application I'm running a query on DocumentDb in .NET. For this used I wanted to use a parametrized query, like this:
var sqlString = "select p.Id, p.ActionType, p.Type, p.Region, a.TimeStamp, a.Action from History p join a in p.Actions where a.TimeStamp >= #StartTime and a.TimeStamp <= #EndTime and p.ClientId = #ClientId and p.ActionType = #ActionType";
if (actionType != "") { sqlString += actionTypeFilter; }
var queryObject = new SqlQuerySpec
{
QueryText = sqlString,
Parameters = new SqlParameterCollection()
{
new SqlParameter("#StartTime", startDate),
new SqlParameter("#EndTime", endDate),
new SqlParameter("#ClientId", clientId.ToString()),
new SqlParameter("#ActionType", actionType)
},
};
var dataListing = _documentDbClient.CreateDocumentQuery<PnrTransaction>(UriToPnrHistories, queryObject, new FeedOptions() { MaxItemCount = 1 });
When I execute this, I'm getting en empty dataset. But when I use the same query, and build it using classic string replace it works just fine.
Can anyone tell me what I'm doing wrong in my parametrized query?
If the code above is the running code, you still add the actiontypeFilter on the parameterized SQL string. Try to remove the if statement on line 2. Seems to me that may be your problem.
It would help if you could post a sample document from the server.
I usually see this syntax:
SqlParameterCollection parameters = new SqlParameterCollection();
parameters.Add(...);
parameters.Add(...);
Try that and see if you get different results. It might be that the list you use to initialize it in your answer needs to be typed differently to work.
Related
I have a class Node extends V. I add instances to Node with some set of document type information provided. I want to query the OrientDB database and return some information from Node; to display this in a formatted way I want a list of all possible field names (in my application, there are currently 115 field names, only one of which is a property used as an index)
To do this in pyorient, the only solution I found so far is (client is the name of the database handle):
count = client.query("SELECT COUNT(*) FROM Node")[0].COUNT
node_records = client.query("SELECT FROM Node LIMIT {0}".format(count))
node_key_list = set([])
for node in node_records:
node_key_list |= node.oRecordData.keys()
I figured that much out pretty much through trial and error. It isn't very efficient or elegant. Surely there must be a way to have the database return a list of all possible fields for a class or any other document-type object. Is there a simple way to do this through either pyorient or the SQL commands?
I tried your case with this dataset:
And this is the structure of my class TestClass:
As you can see from my structure only name, surname and timeStamp have been created in schema-full mode, instead nameSchemaLess1 and nameSchemaLess1 have been inserted into the DB in schema-less mode.
After having done that, you could create a Javascript function in OrientDB Studio or Console (as explained here) and subsequently you can recall it from pyOrient by using a SQL command.
The following posted function retrieves all the fields names of the class TestClass without duplicates:
Javascript function:
var g = orient.getGraph();
var fieldsList = [];
var query = g.command("sql", "SELECT FROM TestClass");
for (var x = 0; x < query.length; x++){
var fields = query[x].getRecord().fieldNames();
for (var y = 0; y < fields.length; y++) {
if (fieldsList == false){
fieldsList.push(fields[y]);
} else {
var fieldFound = false;
for (var z = 0; z < fieldsList.length; z++){
if (fields[y] == fieldsList[z]){
fieldFound = true;
break;
}
}
if (fieldFound != true){
fieldsList.push(fields[y]);
}
}
}
}
return fieldsList;
pyOrient code:
import pyorient
db_name = 'TestDatabaseName'
print("Connecting to the server...")
client = pyorient.OrientDB("localhost", 2424)
session_id = client.connect("root", "root")
print("OK - sessionID: ", session_id, "\n")
if client.db_exists(db_name, pyorient.STORAGE_TYPE_PLOCAL):
client.db_open(db_name, "root", "root")
functionCall = client.command("SELECT myFunction() UNWIND myFunction")
for idx, val in enumerate(functionCall):
print("Field name: " + val.myFunction)
client.db_close()
Output:
Connecting to the server...
OK - sessionID: 54
Field name: name
Field name: surname
Field name: timeStamp
Field name: out_testClassEdge
Field name: nameSchemaLess1
Field name: in_testClassEdge
Field name: nameSchemaLess2
As you can see all of the fields names, both schema-full and schema-less, have been retrieved.
Hope it helps
Luca's answer worked. I modified it to fit my tastes/needs. Posting here to increase the amount of OrientDB documentation on Stack Exchange. I took Luca's answer and translated it to groovy. I also added a parameter to select the class to get fields for and removed the UNWIND in the results. Thank you to Luca for helping me learn.
Groovy code for function getFieldList with 1 parameter (class_name):
g = orient.getGraph()
fieldList = [] as Set
ret = g.command("sql", "SELECT FROM " + class_name)
for (record in ret) {
fieldList.addAll(record.getRecord().fieldNames())
}
return fieldList
For the pyorient part, removing the database connection it looks like this:
node_keys = {}
ret = client.command("SELECT getFieldList({0})".format("'Node'"))
node_keys = ret[0].oRecordData['getFieldList']
Special notice to the class name; in the string passed to client.command(), the parameter must be encased in quotes.
Our code has a SqlExpression, which at its bare minimum is something like:
var q = db.From<Users>();
q.Where(u => u.Age == 25);
totalRecords = db.Scalar<int>(q.ToCountStatement());
q.ToCountStatement() generates the following query:
SELECT COUNT(*) FROM "Users" WHERE ("Age" = #0)
However, db.Scalar() throws an exception: Must declare the scalar variable "#0". This has started occurring in recent versions (tested in 4.0.54). The same code was working fine until v4.0.50. I've checked the release notes, but couldn't find a related change.
Even passing a parameter throws the same exception:
totalRecords = db.Scalar<int>(q.ToCountStatement(), 25);
Is it a bug, or my oversight?
Secondly, is it possible to get q.ToCountStatement() to generate a more optimized query with COUNT(Age) or COUNT([PrimaryKey]) instead of COUNT(*)?
Now that OrmLite defaults to parameterized queries you also need to provide the queries db parameters when executing a query (if you've specified any params), e.g:
var q = db.From<Users>().Where(u => u.Age == 25);
var count = db.Scalar<int>(q.ToCountStatement(), q.Params);
You can also use OrmLite's explicit Count() API's, e.g:
db.Count<User>(x => x.Age == 25);
Or with a typed SqlExpression:
var q = db.From<User>().Where(x => x.Age == 25);
db.Count(q);
Otherwise another way to specify db params is to use an anonymous object, e.g:
db.Scalar<int>("SELECT COUNT(*) FROM Users WHERE Age=#age", new { age = 25});
I am offloading my search feature on a relational database to Azure Search. My Products tables contains columns like serialNumber, PartNumber etc.. (there can be multiple serialNumbers with the same partNumber).
I want to create a suggestor that can autocomplete partNumbers. But in my scenario I am getting a lot of duplicates in the suggestions because the partNumber match was found in multiple entries.
How can I solve this problem ?
The Suggest API suggests documents, not queries. If you repeat the partNumber information for each serialNumber in your index and then suggest based on partNumber, you will get a result for each matching document. You can see this more clearly by including the key field in the $select parameter. Azure Search will eliminate duplicates within the same document, but not across documents. You will have to do that on the client side, or build a secondary index of partNumbers just for suggestions.
See this forum thread for a more in-depth discussion.
Also, feel free to vote on this UserVoice item to help us prioritize improvements to Suggestions.
I'm facing this problem myself. My solution does not involve a new index (this will only get messy and cost us money).
My take on this is a while-loop adding 'UserIdentity' (in your case, 'partNumber') to a filter, and re-search until my take/top-limit is met or no more suggestions exists:
public async Task<List<MachineSuggestionDTO>> SuggestMachineUser(string searchText, int take, string[] searchFields)
{
var indexClientMachine = _searchServiceClient.Indexes.GetClient(INDEX_MACHINE);
var suggestions = new List<MachineSuggestionDTO>();
var sp = new SuggestParameters
{
UseFuzzyMatching = true,
Top = 100 // Get maximum result for a chance to reduce search calls.
};
// Add searchfields if set
if (searchFields != null && searchFields.Count() != 0)
{
sp.SearchFields = searchFields;
}
// Loop until you get the desired ammount of suggestions, or if under desired ammount, the maximum.
while (suggestions.Count < take)
{
if (!await DistinctSuggestMachineUser(searchText, take, searchFields, suggestions, indexClientMachine, sp))
{
// If no more suggestions is found, we break the while-loop
break;
}
}
// Since the list might me bigger then the take, we return a narrowed list
return suggestions.Take(take).ToList();
}
private async Task<bool> DistinctSuggestMachineUser(string searchText, int take, string[] searchFields, List<MachineSuggestionDTO> suggestions, ISearchIndexClient indexClientMachine, SuggestParameters sp)
{
var response = await indexClientMachine.Documents.SuggestAsync<MachineSearchDocument>(searchText, SUGGESTION_MACHINE, sp);
if(response.Results.Count > 0){
// Fix filter if search is triggered once more
if (!string.IsNullOrEmpty(sp.Filter))
{
sp.Filter += " and ";
}
foreach (var result in response.Results.DistinctBy(r => new { r.Document.UserIdentity, r.Document.UserName, r.Document.UserCode}).Take(take))
{
var d = result.Document;
suggestions.Add(new MachineSuggestionDTO { Id = d.UserIdentity, Namn = d.UserNamn, Hkod = d.UserHkod, Intnr = d.UserIntnr });
// Add found UserIdentity to filter
sp.Filter += $"UserIdentity ne '{d.UserIdentity}' and ";
}
// Remove end of filter if it is run once more
if (sp.Filter.EndsWith(" and "))
{
sp.Filter = sp.Filter.Substring(0, sp.Filter.LastIndexOf(" and ", StringComparison.Ordinal));
}
}
// Returns false if no more suggestions is found
return response.Results.Count > 0;
}
public async Task<List<string>> SuggestionsAsync(bool highlights, bool fuzzy, string term)
{
SuggestParameters sp = new SuggestParameters()
{
UseFuzzyMatching = fuzzy,
Top = 100
};
if (highlights)
{
sp.HighlightPreTag = "<em>";
sp.HighlightPostTag = "</em>";
}
var suggestResult = await searchConfig.IndexClient.Documents.SuggestAsync(term, "mysuggestion", sp);
// Convert the suggest query results to a list that can be displayed in the client.
return suggestResult.Results.Select(x => x.Text).Distinct().Take(10).ToList();
}
After getting top 100 and using distinct it works for me.
You can use the Autocomplete API for that where does the grouping by default. However, if you need more fields together with the result, like, the partNo plus description it doesn't support it. The partNo will be distinct though.
I am reading a table from a sqlite3 database. I managed to read an int field ( iEventYear in my code sample )
But I don't know howto read a string field from sqlite database.
I would like to use no additional library or framework, but the pure included sqlite3.h if possible.
Here's my code to demonstrate my problem:
let sql = "SELECT year,title FROM historyevents";
var statement:COpaquePointer = nil
//var tail: CString = ""
if sqlite3_prepare_v2(db, sql, -1, &statement, nil) != SQLITE_OK {
println("Failed to prepare statement")
exit(1)
}else{
while sqlite3_step(statement) == SQLITE_ROW {
var iEventYear:Int16 = Int16(sqlite3_column_int(statement, 0));
//Howto retrieve a string ?
var sEventTitle:String = String(sqlite3_column_xxxxxx(statement, 1));
println(count);
}
println("query ok.");
}
You should be able to retrieve a String in this way.
let sEventTitle = String.fromCString(UnsafePointer<CChar>(sqlite3_column_text(statement, 1)))
However my advice is to use a SQLite wrapper, one of the most famous is FMDB, it's in
Objective-C (obviously works well also in Swift), but if you prefer something completely in Swift, you can look at SwiftSQLite
here my issue:
I've an IQueryable object and I need to execute a new query on Db (just like a refresh) by launching the same contained query in my IQueryable obj.
An example:
myObj = objCtx.Person
.Where(p => p.IdPerson...)
.OrderBy(p => ...)
.Select(..some field..);
//...
// From another function I just want re-execute
// the same query
// -> Well, that retrieve full lambda
var et = this.myObj.Expression
// This doesn't work:
var anotherObj = objCtx.Person.Where(et);
//or..
var tmp = Expression.Lambda<Func<T, bool>>(et);
// This doesn't work too:
var anotherObj = objCtx.Person.Where(tmp);
Is it possibile to achieve? What am I missing?
Thanks
Ok:
I would be able to retrieve full query (select statement) from an IQueryable object and execute it in order to get all my updated data.
This is the original query:
this.myIQueryableObj = objCtx.Person
.Where(p => p.IdPerson...)
.OrderBy(p => ...)
.Select(..some field..);
//..And in some button click, I want execute again the above query, but all what I know is myIQueryableObjOnly. Can you help me?