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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's the reason for “Error:Cannot determine Java VM executable in selected JDK”?
...ettings from project context menu (or default hit F4), then from left tab select Project and point correct Project SDK on dropdown.
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How do you list the primary key of a SQL Server table?
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SELECT Col.Column_Name from
INFORMATION_SCHEMA.TABLE_CONSTRAINTS Tab,
INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE Col
WHERE
Col.Constraint_Name = Tab.Constraint_Name
AND Col.Table_Name = Tab.Table_Name
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How to find largest objects in a SQL Server database?
...quite a bit understanding and determining the size of indices and tables:
SELECT
t.name AS TableName,
i.name as indexName,
sum(p.rows) as RowCounts,
sum(a.total_pages) as TotalPages,
sum(a.used_pages) as UsedPages,
sum(a.data_pages) as DataPages,
(sum(a.total_pages) *...
Calculate difference between two datetimes in MySQL
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USE TIMESTAMPDIFF MySQL function. For example, you can use:
SELECT TIMESTAMPDIFF(SECOND, '2012-06-06 13:13:55', '2012-06-06 15:20:18')
In your case, the third parameter of TIMSTAMPDIFF function would be the current login time (NOW()). Second parameter would be the last login time, w...
SQLite select where empty?
In SQLite, how can I select records where some_column is empty?
Empty counts as both NULL and "".
4 Answers
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How to convert int to char with leading zeros?
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Try this: select right('00000' + cast(Your_Field as varchar(5)), 5)
It will get the result in 5 digits, ex: 00001,...., 01234
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LINQ query on a DataTable
...w in myDataTable.AsEnumerable()
where myRow.Field<int>("RowNo") == 1
select myRow;
And as @Keith says, you'll need to add a reference to System.Data.DataSetExtensions
AsEnumerable() returns IEnumerable<DataRow>. If you need to convert IEnumerable<DataRow> to a DataTable, use the...
Select TreeView Node on right click before displaying ContextMenu
I would like to select a WPF TreeView Node on right click, right before the ContextMenu displayed.
11 Answers
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How to COUNT rows within EntityFramework without loading contents?
... where o.ID == '1'
from t in o.MyTable
select t).Count();
Method syntax:
var count = context.MyContainer
.Where(o => o.ID == '1')
.SelectMany(o => o.MyTable)
.Count()
Both generate the same SQL query.
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