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How do I delete from multiple tables using INNER JOIN in SQL server
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You can take advantage of the "deleted" pseudo table in this example. Something like:
begin transaction;
declare @deletedIds table ( id int );
delete from t1
output deleted.id into @deletedIds
from table1 as t1
inner join table2 as t2
on t2.id = t...
Remove Identity from a column in a table
We have a 5GB table (nearly 500 million rows) and we want to remove the identity property on one of the column, but when we try to do this through SSMS - it times out.
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Linq to Sql: Multiple left outer joins
...se id that was passed in
from category
// left join on categories table if exists
in expenseDataContext.CategoryDtos
.Where(c => c.Id == expense.CategoryId)
.DefaultIfEmpty()
// left join on expense type table if exists
from ...
data.table vs dplyr: can one do something well the other can't or does poorly?
I'm relatively familiar with data.table , not so much with dplyr . I've read through some dplyr vignettes and examples that have popped up on SO, and so far my conclusions are that:
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map vs. hash_map in C++
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hash_map (unordered_map in TR1 and Boost; use those instead) use a hash table where the key is hashed to a slot in the table and the value is stored in a list tied to that key.
map is implemented as a balanced binary search tree (usually a red/black tree).
An unordered_map should give slightly ...
C++使用OLE/COM高速读写EXCEL的源码 - C/C++ - 清泛网 - 专注C/C++及内核技术
...ColumnCount();
///使用某个shet，shit，shit
BOOL LoadSheet(long table_index,BOOL pre_load = FALSE);
///通过名称使用某个sheet，
BOOL LoadSheet(const TCHAR* sheet,BOOL pre_load = FALSE);
///通过序号取得某个Sheet的名称
CString GetSheetName(long table_index);
/...
How do you find the row count for all your tables in Postgres
I'm looking for a way to find the row count for all my tables in Postgres. I know I can do this one table at a time with:
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SQLite in Android How to update a specific row
...2","Male");
Then use the update method, it should work now:
myDB.update(TableName, cv, "_id="+id, null);
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How do you convert a DataTable into a generic list?
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If you're using .NET 3.5, you can use DataTableExtensions.AsEnumerable (an extension method) and then if you really need a List<DataRow> instead of just IEnumerable<DataRow> you can call Enumerable.ToList:
IEnumerable<DataRow> sequence = dt.AsEnume...
I want to copy table contained from one database and insert onto another database table
I want to copy a table's schema as well as the data within that table to another database table in another database on a live server. How could I do this?
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