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Dynamically select data frame columns using $ and a character value
...the second is a data.frame
mtcars[[var]]
mtcars[var]
You can perform the ordering without loops, using do.call to construct the call to order. Here is a reproducible example below:
# set seed for reproducibility
set.seed(123)
df <- data.frame( col1 = sample(5,10,repl=T) , col2 = sample(5,10,r...
SQLiteDatabase.query method
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whereArgs
specify the content that fills each ? in whereClause in the order they appear
the others
just like whereClause the statement after the keyword or null if you don't use it.
Example
String[] tableColumns = new String[] {
"column1",
"(SELECT max(column1) FROM table2) AS ma...
What does collation mean?
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Collation can be simply thought of as sort order.
In English (and it's strange cousin, American), collation may be a pretty simple matter consisting of ordering by the ASCII code.
Once you get into those strange European languages with all their accents and other fe...
jQuery UI Sortable, then write order into a database
I want to use the jQuery UI sortable function to allow users to set an order and then on change, write it to the database and update it. Can someone write an example on how this would be done?
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MVC Razor view nested foreach's model
...el=>model.Theme[themeIndex].Products[productIndex].name)
@for(var orderIndex=0; orderIndex < Model.Theme[themeIndex].Products[productIndex].Orders; orderIndex++)
{
@Html.TextBoxFor(model => model.Theme[themeIndex].Products[productIndex].Orders[orderIndex].Quantity)
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Grouped LIMIT in PostgreSQL: show the first N rows for each group?
I need to take the first N rows for each group, ordered by custom column.
5 Answers
5
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How do you find the disk size of a Postgres / PostgreSQL table and its indexes
...ema || '"."' || table_name || '"')) AS size
FROM information_schema.tables
ORDER BY
pg_total_relation_size('"' || table_schema || '"."' || table_name || '"') DESC;
Edit: Here's the query submitted by @phord, for convenience:
SELECT
table_name,
pg_size_pretty(table_size) AS table_size,...
How to check date of last change in stored procedure or function in SQL server
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SELECT name, create_date, modify_date
FROM sys.objects
WHERE type = 'P'
ORDER BY modify_date DESC
The type for a function is FN rather than P for procedure. Or you can filter on the name column.
share
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Real life example, when to use OUTER / CROSS APPLY in SQL
... WHERE pa.object_id = pr.object_id
ORDER BY pr.name) pa
ORDER BY pr.name,
pa.name
2) Calling a Table Valued Function for each row in the outer query
SELECT *
FROM sys.dm_exec_query_stats AS qs
CROSS APPLY sys.dm_exec_query_plan(qs.plan_handle)
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Reorder levels of a factor without changing order of values
...with some numerical variables and some categorical factor variables. The order of levels for those factors is not the way I want them to be.
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