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Stacking Divs from Bottom to Top
...e. If you only need this to work for modern browsers and IE 8+ you can use table positioning, vertical-align:bottom and max-height. See MDN for specific browser compatibility.
Demo (vertical-align)
.wrapper {
display: table-cell;
vertical-align: bottom;
height: 200px;
}
.content {
max-heig...
SQL: How to properly check if a record exists
...
It's better to use either of the following:
-- Method 1.
SELECT 1
FROM table_name
WHERE unique_key = value;
-- Method 2.
SELECT COUNT(1)
FROM table_name
WHERE unique_key = value;
The first alternative should give you no result or one result, the second count should be zero or one.
How old is...
Can PostgreSQL index array columns?
...e to use the array operators and the GIN-index type.
Example:
CREATE TABLE "Test"("Column1" int[]);
INSERT INTO "Test" VALUES ('{10, 15, 20}');
INSERT INTO "Test" VALUES ('{10, 20, 30}');
CREATE INDEX idx_test on "Test" USING GIN ("Column1");
-- To enforce index usage because...
What does the ^ operator do in Java?
... 6 = 110
------------------ xor
3 = 011
This the truth table for bitwise (JLS 15.22.1) and logical (JLS 15.22.2) xor:
^ | 0 1 ^ | F T
--+----- --+-----
0 | 0 1 F | F T
1 | 1 0 T | T F
More simply, you can also think of xor as "this or that, but not both!".
...
Chrome Extension how to send data from content script to popup.html
...tyle="font-weight:bold; text-align:center;">DOM Info</h3>
<table border="1" cellpadding="3" style="border-collapse:collapse;">
<tr>
<td nowrap>Total number of elements:</td>
<td align="right"><span id="total">N/A</span><...
How do I kill all the processes in Mysql “show processlist”?
...<USERNAME> -p<PASSWORD>
mysqladmin processlist will print a table with the thread ids;
awk will parse from the second column only the numbers (thread ids) and generate MySQL KILL commands;
and finally the last call to mysql will execute the passed commands.
You can run grep before t...
How do I format a number with commas in T-SQL?
...p_spaceused in SQL Server 2008 to look at data/index space ratios of some tables in my database. Of course I am getting all sorts of large numbers in the results and my eyes are starting to gloss over. It would be really convenient if I could format all those numbers with commas (987654321 become...
Determine whether an array contains a value [duplicate]
...oject and nowadays it's Babel :) big win for JavaScript community! There's table of what's available of ES7 already on many platforms including babel pollyfils kangax.github.io/compat-table/es2016plus
– Lukas Liesis
Jul 12 '16 at 9:52
...
Paste multiple columns together
...# 3 3 c-f-i
Alternatively we could update data in place using the data.table package (assuming fresh data)
library(data.table)
setDT(data)[, x := Reduce(function(...) paste(..., sep = "-"), .SD[, mget(cols)])]
data[, (cols) := NULL]
data
# a x
# 1: 1 a-d-g
# 2: 2 b-e-h
# 3: 3 c-f-i
Ano...
What's faster, SELECT DISTINCT or GROUP BY in MySQL?
If I have a table
15 Answers
15
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