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differentiate null=True, blank=True in django
...e)
The database fields created for PostgreSQL 9.4 are :
CREATE TABLE Test (
id serial NOT NULL,
"charNull" character varying(10),
"charBlank" character varying(10) NOT NULL,
"charNullBlank" character varying(10),
"intNull" in...
Differences between MySQL and SQL Server [closed]
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I can't believe that no one mentioned that MySQL doesn't support Common Table Expressions (CTE) / "with" statements. It's a pretty annoying difference.
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Imitating a blink tag with CSS3 animations
... +animation(blink 1s 0s reverse infinite)
+transform(translateZ(0))
.table
display: table
height: 5em
width: 100%
vertical-align: middle
.cell
display: table-cell
width: 100%
height: 100%
vertical-align: middle
http://codepen.io/anon/pen/kaGxC (sass with bourbon)
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Postgresql query between date ranges
...= 2
This involves calculating the conditions for every single row in the table (a scan) and not using index to find the range of rows that will match (a range-seek).
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Select where count of one field is greater than one
...e result comparison.
Taking the query at face value:
SELECT *
FROM db.table
HAVING COUNT(someField) > 1
Ideally, there should be a GROUP BY defined for proper valuation in the HAVING clause, but MySQL does allow hidden columns from the GROUP BY...
Is this in preparation for a unique cons...
How do I do a bulk insert in mySQL using node.js
...Ragnar123 led me to making this function:
function bulkInsert(connection, table, objectArray, callback) {
let keys = Object.keys(objectArray[0]);
let values = objectArray.map( obj => keys.map( key => obj[key]));
let sql = 'INSERT INTO ' + table + ' (' + keys.join(',') + ') VALUES ?';
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How to test an SQL Update statement before running it?
...man/5.0/en/commit.html
For example:
START TRANSACTION;
SELECT * FROM nicetable WHERE somthing=1;
UPDATE nicetable SET nicefield='VALUE' WHERE somthing=1;
SELECT * FROM nicetable WHERE somthing=1; #check
COMMIT;
# or if you want to reset changes
ROLLBACK;
SELECT * FROM nicetable WHERE somthing=1...
postgresql return 0 if returned value is null
...al question).
There are two distinct "problems" here, the first is if a table or subquery has no rows, the second is if there are NULL values in the query.
For all versions I've tested, postgres and mysql will ignore all NULL values when averaging, and it will return NULL if there is nothing to ...
What characters are allowed in an email address?
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I've tried to implement this in postfix via pcre access table under a check_recipient_access restriction, first turning the 3 long pcres (from the linked page) into one line each and topping and tailing thus: /^[...pcre..]$/ DUNNO, then adding a final line /.*/ REJECT, but it stil...
How do I update if exists, insert if not (AKA “upsert” or “merge”) in MySQL?
... @blub: If you create a unique key on geb and topic it will work (ALTER TABLE table ADD UNIQUE geb_by_topic (geb, topic)).
– chaos
Aug 2 '09 at 13:43
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