Querying a LinqToSql result - vb.net

Let's say I have a Persons table with two columns:
ID (Uniqueidentifier)
Name (NChar)
I need to get all my persons first:
Dim data = (From p In Persons Select p).ToList
Now that I got all persons in the data variable, is it possible to query this result using a string query? Like...
Dim filtered = (From p In data Select p).Where("Name Like '%John%').ToList
?
I need to build the query on the fly.
Thanks

var filtered = data.Where(a =>
SqlMethods.Like(a.name.ToString(), "%" +
Request.QueryString["search"] + "%"));
i use querystring as an example for dynamic value, and use it in sql like method,
which is similiar to sql like, in your case "request.querystring["search"] value is john"

Try this:
from p in data
where SqlMethods.Like(p.Name, "%"+parameter+"%")
select p;
parameter in your example should be John.

Related

LIKE with integers in PostgreeSQL using R

I need to download a table from postgree to R, but filtered by part of an INT.
I have been trying:
library(RPostgreSQL)
con <- dbConnect(PostgreSQL(), user= "#####", dbname="######",password="#####"
,host="#####", port='######')
vetor_id <- c("83052407","10406587","12272377")
match_id <- dbGetQuery(con,paste("
SELECT *
FROM public.data2015
WHERE id IN ('", paste(vetor_id,collapse = "','"),"')
",sep = ""))
dbDisconnect(con)
I also tried CONTAINS but didn't work.WHERE Contains(id,", paste(vetor_id,collapse = " OR "),"')
id is INT and vetor_id is just part of the values. I mean,vector_id = 83052407 must find id = 83052407000132.
How can I use something like LIKE and put vetor_id% ?
Is this what you want?
WHERE id::text like ? || '%'
This converts the integer id to a string, and attempts to match it against the parameter. If id starts with the parameter, the condition is satisfied.
Note that this uses a legitimate query parameter (represented by the question mark): you should get used to parameterize your queries rather than concatenating variables in the query string: this is cleaner, more efficient and safer.

How to convert Sql inner query to Linq for sum of column

How to Convert this sql query to Linq.
select sum(OutstandingAmt)from IvfReceiptDetails where IvfReceiptId IN(select IvfReceiptId from IvfReceipts where PatientId = 'SI-49650')
I think it is easier to translate SQL using query comprehension syntax instead of lambda syntax.
General rules:
Translate inner queries into separate query variables
Translate SQL phrases in LINQ phrase order
Use table aliases as range variables, or if none, create range variables from table names
Translate IN to Contains
Translate SQL functions such as DISTINCT or SUM into function calls on the entire query.
Here is the code:
var IvfReceiptIds = from IvfReceipt in IvfReceipts
where IvfReceipt.PatientId = "SI-49650"
select IvfReceipt.IvfReceiptId;
var OutstandingAmtSum = (from IvfReceiptDetail in IvfReceiptDetails
where IvfReciptIds.Contains(IvfReceiptDetail.IvfReceiptId)
select IvfReceiptDetail.OutstandingAmt).Sum();
Try this, First get all IvfReceiptId in array based on your inner query used in where condition then check contains. Change name of your _context if it's different.
var arrIvfReceiptId = _context.IvfReceiptDetails.Where(p=>p.PatientId == "SI-49650").ToArray();
var sum = (from ird in _context.IvfReceiptDetails.Where(p=> arrIvfReceiptId.Contains(p.IvfReceiptId))
select OutstandingAmt).Sum();

Hibernate return empty result if using LIKE condition with univarchar columns (Sybase)

Let's suppose I have a table: Person(Name: univarchar) and this table contains a row "abc".
I search Person by using Hibernate (Criteria API and HQL):
Criteria API:
Criteria c = session.createCriteria(Person.class);
c.add(Restrictions.ilike(name,"abc"));
return c.list();
HQL:
String query = "from Person where lower(name) like :name";
Query q = session.createQuery(query);
query.setString("name","abc");
return query.list();
It return empty result. However, when I use Interactive SQL of Sybase to execute SQL statement that is generated by Hibernate, it return a row "abc".
I found a solution for HQL case. This is to use rtrim function:
String query = "from Person where lower(rtrim(name)) like :name";
...
But my problem is I want to use Criteria API and I cannot find any ways to trim name column by using Criteria API.
Thanks and sorry for my poor English.
Have you tried with this code :
Criteria c = session.createCriteria(Person.class);
c.add(Restrictions.ilike(name,"abc",MatchMode.ANYWHERE));
return c.list();
If this will not work then Read this. Its similar Just he wants to trim while Order you want to trim while Restrictions.

NHibernate native SQL in WHERE clause

I have a Geography column in a table in SQL Server and would like to filter rows with a specific geometry type, e.g. all records where geometry type is 'Point'
The SQL query would look like
select * from GeometryTable g where g.Geography.STGeometryType() = 'Point'
How can I create a criteria for that? The criteria is going to be used with other criterias
criteria.Add(Restrictions.Add(<Geography.STGeometryType()>, some.Value)
Thanks
Use this syntax:
var criteria = session.CreateCriteria<Geometry>();
criteria.Add
(
Expression.Sql(" {alias}.[Geography].STGeometryType() = ? "
, "Point" // a place for your parameter
, NHibernate.NHibernateUtil.String)
);
var list = criteria.List<Geometry>();

multiple parameter "IN" prepared statement

I was trying to figure out how can I set multiple parameters for the IN clause in my SQL query using PreparedStatement.
For example in this SQL statement, I'll be having indefinite number of ?.
select * from ifs_db where img_hub = ? and country IN (multiple ?)
I've read about this in
PreparedStatement IN clause alternatives?
However I can't figure it out how to apply it to my SQL statement above.
There's not a standard way to handle this.
In SQL Server, you can use a table-valued parameter in a stored procedure and pass the countries in a table and use it in a join.
I've also seen cases where a comma-separated list is passed in and then parsed into a table by a function and then used in a join.
If your countries are standard ISO codes in a delimited list like '#US#UK#DE#NL#', you can use a rather simplistic construct like:
select * from ifs_db where img_hub = ? and ? LIKE '%#' + country + '#%'
Sormula will work for any data type (even custom types). This example uses int's for simplicity.
ArrayList<Integer> partNumbers = new ArrayList<Integer>();
partNumbers.add(999);
partNumbers.add(777);
partNumbers.add(1234);
// set up
Database database = new Database(getConnection());
Table<Inventory> inventoryTable = database.getTable(Inventory.class);
ArrayListSelectOperation<Inventory> operation =
new ArrayListSelectOperation<Inventory>(inventoryTable, "partNumberIn");
// show results
for (Inventory inventory: operation.selectAll(partNumbers))
System.out.println(inventory.getPartNumber());
You could use setArray method as mentioned in the javadoc below:
http://docs.oracle.com/javase/6/docs/api/java/sql/PreparedStatement.html#setArray(int, java.sql.Array)
Code:
PreparedStatement statement = connection.prepareStatement("Select * from test where field in (?)");
Array array = statement.getConnection().createArrayOf("VARCHAR", new Object[]{"AA1", "BB2","CC3"});
statement.setArray(1, array);
ResultSet rs = statement.executeQuery();