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SQL select join: is it possible to prefix all columns as 'prefix.*'?
... if this is possible in SQL. Say you have two tables A and B, and you do a select on table A and join on table B:
22 Answer...
MySQL selecting yesterday's date
...get yesterday's date is:
subdate(current_date, 1)
Your query would be:
SELECT
url as LINK,
count(*) as timesExisted,
sum(DateVisited between UNIX_TIMESTAMP(subdate(current_date, 1)) and
UNIX_TIMESTAMP(current_date)) as timesVisitedYesterday
FROM mytable
GROUP BY 1
For the ...
How to Select Columns in Editors (Atom,Notepad++, Kate, VIM, Sublime, Textpad,etc) and IDEs (NetBean
How to select columns in Editors and IDEs to columnar delete, insert or replace some characters ?
21 Answers
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Get the Highlighted/Selected text
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Getting the text the user has selected is relatively simple. There's no benefit to be gained by involving jQuery since you need nothing other than the window and document objects.
function getSelectionText() {
var text = "";
if (window.getSelecti...
Delete column from SQLite table
... TRANSACTION;
CREATE TEMPORARY TABLE t1_backup(a,b);
INSERT INTO t1_backup SELECT a,b FROM t1;
DROP TABLE t1;
CREATE TABLE t1(a,b);
INSERT INTO t1 SELECT a,b FROM t1_backup;
DROP TABLE t1_backup;
COMMIT;
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Oracle “Partition By” Keyword
...d then use that in a calculation against this records salary without a sub select, which is much faster.
Read the linked AskTom article for further details.
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How to check Oracle database for long running queries
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This one shows SQL that is currently "ACTIVE":-
select S.USERNAME, s.sid, s.osuser, t.sql_id, sql_text
from v$sqltext_with_newlines t,V$SESSION s
where t.address =s.sql_address
and t.hash_value = s.sql_hash_value
and s.status = 'ACTIVE'
and s.username <> 'SYSTEM'
ord...
Only read selected columns
...from the data.table-package:
You can specify the desired columns with the select parameter from fread from the data.table package. You can specify the columns with a vector of column names or column numbers.
For the example dataset:
library(data.table)
dat <- fread("data.txt", select = c("Year...
JOIN queries vs multiple queries
...han several queries? (You run your main query, and then you run many other SELECTs based on the results from your main query)
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PostgreSQL query to return results as a comma separated list
Let say you have a SELECT id from table query (the real case is a complex query) that does return you several results.
5 ...