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linq query to return distinct field values from a list of objects
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objList.Select(o=>o.typeId).Distinct()
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What columns generally make good indexes?
...earching the results speedily from tables. So it is most important step to select which columns to be indexed. There are two major places where we can consider indexing: columns referenced in the WHERE clause and columns used in JOIN clauses. In short, such columns should be indexed against which yo...
How to force LINQ Sum() to return 0 while source collection is empty
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&& l.Property.PropertyId == PropertyId)
.Select(l => l.Amount)
.DefaultIfEmpty(0)
.Sum();
This way, your query will only select the Amount field. If the collection is empty, it will return one element with the value of 0 and then the sum will ...
Why can't radio buttons be “readonly”?
...ton by disabling only the un-checked radio buttons. It keeps the user from selecting a different value, and the checked value will always post on submit.
Using jQuery to make readonly:
$(':radio:not(:checked)').attr('disabled', true);
This approach also worked for making a select list readonly, ...
Why does changing the returned variable in a finally block not change the return value?
...le s", you set s to refer to the inlined String, not altering the inherent char buffer of the s object to change to "override variable s".
You put a reference to the s on the stack to return to the calling code. Afterwards (when the finally block runs), altering the reference should not do anything ...
Salting Your Password: Best Practices?
...mantics. Pick a different salt per password, a long salt, and include odd characters in it like symbols and ASCII codes: ©¤¡
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Comparing date ranges
... range_start, here's some simple SQL to retrieve all the matching rows:
SELECT *
FROM periods
WHERE NOT (range_start > @check_period_end
OR range_end < @check_period_start)
Note the NOT in there. Since the two simple rules finds all the non-matching rows, a simple NOT will reve...
“A lambda expression with a statement body cannot be converted to an expression tree”
...SQL to be executed against the database.
Try this
Arr[] myArray = objects.Select(o => new Obj() {
Var1 = o.someVar,
Var2 = o.var2
}).ToArray();
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How to Delete using INNER JOIN with SQL Server?
...helpful for you -
DELETE FROM dbo.WorkRecord2
WHERE EmployeeRun IN (
SELECT e.EmployeeNo
FROM dbo.Employee e
WHERE ...
)
Or try this -
DELETE FROM dbo.WorkRecord2
WHERE EXISTS(
SELECT 1
FROM dbo.Employee e
WHERE EmployeeRun = e.EmployeeNo
AND ....
)
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Easiest way to copy a table from one database to another?
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CREATE TABLE db1.table1 SELECT * FROM db2.table1
where db1 is the destination and db2 is the source
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