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();
Related
Consider the following statements. The first one is a LINQ statement, and the second one is old fashioned SQL. They both produce the correct result. The LINQ statement takes 42 seconds because it doesn’t pass the where clause to Oracle. Oracle has to do a complete table scan, then the where clause is satisfied by LINQ after the result. In contrast, the SQL passes the where clause to Oracle, and takes about 3 seconds to run.
Why doesn’t LINQ pass the where clause to Oracle? What can I do about this?
LINQ:
var SamDlvryGrps3 = (from x in _entities.VW_QCRPT_SAMPLE_DLVRY_GRP_SITE
where x.SAMPLEDELIVERYGROUP == EnteredsmplDlvryGrp
select new BatchIdModView
{
BatchId = x.BATCHID,
sampleDeliveryGroup = x.SAMPLEDELIVERYGROUP
}).Distinct().ToList();
SQL:
string sql = "select distinct BatchId, sampleDeliveryGroup from VW_QCRPT_SAMPLE_DLVRY_GRP_SITE where SAMPLEDELIVERYGROUP = :1";
List<BatchIdModView> SamDlvryGrps = _entities.Database.SqlQuery<BatchIdModView>
(sql, new OracleParameter("#smplDlvryGrp", EnteredsmplDlvryGrp.ToUpper())).ToList();
In traditional sql we can chain expression according to if statements.
for example lets say I have variable called "firstName" and I want to get from database all users according to the value in this variable(if empty get all users)
so I will chain the sql string like that
string sql="";
if(firstname!="")
sql=String.format(" And firstname='{0}',firstName)
.ExecuteReader(System.Data.CommandType.Text,"select * from users where 1=1" + sql)
Is there a way to copy this Technique to linq expression?
something like
from U in user
where 1=1 & sql
select U
Change to method syntax instead of query syntax, and chaining is easy.
var query = user.Select(u => u);
if(firstname!="")
query = query.Where(u => u.firstname = firstname);
queries in query syntax are converted at compile-time, so there's not a mechanism to "inject" sql at run time using query syntax.
I have the following query.
$query = $this->db->query('SELECT COUNT(*) FROM iplog.persons WHERE begin_date LIKE '2014%'');
I need to count the number of columns with a begin_date in the year 2014.
When I run this script I'm getting an error:
Parse error: syntax error, unexpected '2014' (T_LNUMBER) in C:\xampp\htdocs\iPlog2\application\controllers\stat.php on line 12
I was trying to change my CI script to
$query = $this->db->query('SELECT COUNT(*) FROM iplog.persons WHERE begin_date LIKE "2014%"');
but it caused an error.
You mean, count ROWS:
So for that, just count the number of rows you have based on a condition:
$year = '2014'
$this->db->from('iplog');
$this->db->like('begin_date', $year);
$query = $this->db->get();
$rowcount = $query->num_rows();
First, you have a simple typo regarding the use of single quotes. Your complete sql string should be double quoted so that your value-quoting can be single quoted.
Second, you are using inappropriate query logic. When you want to make a comparison on a DATE or DATETIME type column, you should NEVER be using LIKE. There are specific MYSQL functions dedicated to handling these types. In your case, you should be using YEAR() to isolate the year component of your begin_date values.
Resource: https://www.w3resource.com/mysql/date-and-time-functions/mysql-year-function.php
You could write the raw query like this: (COUNT(*) and COUNT(1) are equivalent)
$count = $this->db
->query("SELECT COUNT(1) FROM persons WHERE YEAR(begin_date) = 2014")
->row()
->COUNT;
Or if you want to employ Codeigniter methods to build the query:
$count = $this->db
->where("YEAR(begin_date) = 2014")
->count_all_results("persons");
You could return all of the values in all of the rows that qualify, but that would mean asking the database for values that you have no intention of using -- this is not best practice. I do not recommend the following:
$count = $this->db
->get_where('persons', 'YEAR(begin_date) = 2014')
->num_rows();
For this reason, you should not be generating a fully populated result set then calling num_rows() or count() when you have no intention of using the values in the result set.
Replace quotes like this :
$query = $this->db->query("SELECT COUNT(*) FROM iplog.persons WHERE begin_date LIKE '2014%'");
Double quote your entire query, then simple quote your LIKE criteria.
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>();
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();