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Selecting/excluding sets of columns in pandas [duplicate]
...e to create views or dataframes from an existing dataframe based on column selections.
9 Answers
...
SQLAlchemy: print the actual query
...s:
print(str(statement))
This applies both to an ORM Query as well as any select() or other statement.
Note: the following detailed answer is being maintained on the sqlalchemy documentation.
To get the statement as compiled to a specific dialect or engine, if the statement itself is not already bo...
How to get first character of a string in SQL?
...
SELECT SUBSTR(thatColumn, 1, 1) As NewColumn from student
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The entity cannot be constructed in a LINQ to Entities query
... p in db.Products
where p.CategoryID == categoryID
select new ProductDTO { Name = p.Name }).ToList();
}
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Hibernate Criteria returns children multiple times with FetchType.EAGER
....class)
.list();
List result = session.createQuery("select o from Order o left join fetch o.lineItems").list();
All of these examples produce the same SQL statement:
SELECT o.*, l.* from ORDER o LEFT OUTER JOIN LINE_ITEMS l ON o.ID = l.ORDER_ID
Want to know why th...
form serialize javascript (no framework)
...
Here is pure JavaScript approach:
var form = document.querySelector('form');
var data = new FormData(form);
var req = new XMLHttpRequest();
req.send(data);
Though it seems to be working only for POST requests.
https://developer.mozilla.org/en-US/docs/Web/API/FormData
...
Linq: adding conditions to the where clause conditionally
... && u.Age > 18
&& u.Height > strHeightinFeet
select u;
if (useAge)
query = query.Where(u => u.Age > age);
if (useHeight)
query = query.Where(u => u.Height > strHeightinFeet);
// Build the results at the end
var results = query.Select(u => new DTO...
Comparing Dates in Oracle SQL
...r by using the built-in TO_DATE() function, or a date literal.
TO_DATE()
select employee_id
from employee
where employee_date_hired > to_date('31-DEC-95','DD-MON-YY')
This method has a few unnecessary pitfalls
As a_horse_with_no_name noted in the comments, DEC, doesn't necessarily mean D...
How to specify a editor to open crontab file? “export EDITOR=vi” does not work
... 13.04 installation) try:
There are a number of alternative ways:
1) Run select-editor
select-editor
2) Manually edit the file: ~/.selected_editor specifying your preferred editor. With this option you can specify editor parameters.
# Generated by /usr/bin/select-editor
SELECTED_EDITOR="/usr/...
How to get ID of the last updated row in MySQL?
...)
SET @update_id := 0;
UPDATE some_table SET column_name = 'value', id = (SELECT @update_id := id)
WHERE some_other_column = 'blah' LIMIT 1;
SELECT @update_id;
EDIT by aefxx
This technique can be further expanded to retrieve the ID of every row affected by an update statement:
SET @uids := nul...