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Select statement to find duplicates on certain fields
...ltiple records, you can use..
select field1,field2,field3, count(*)
from table_name
group by field1,field2,field3
having count(*) > 1
Check this link for more information on how to delete the rows.
http://support.microsoft.com/kb/139444
There should be a criterion for deciding how you defi...
Is there any performance gain in indexing a boolean field?
...is is not entirely correct, without an index mySql needs to scan the whole table to find the relevant rows.
– ilanco
May 9 '12 at 22:04
4
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How do I create a PDO parameterized query with a LIKE statement?
...t out right after I posted:
$query = $database->prepare('SELECT * FROM table WHERE column LIKE ?');
$query->execute(array('value%'));
while ($results = $query->fetch())
{
echo $results['column'];
}
share
...
Check if a row exists, otherwise insert
I need to write a T-SQL stored procedure that updates a row in a table. If the row doesn't exist, insert it. All this steps wrapped by a transaction.
...
Specify custom Date format for colClasses argument in read.table/read.csv
... way to specify the Date format when using the colClasses argument in read.table/read.csv?
4 Answers
...
Sequelize Unknown column '*.createdAt' in 'field list'
...he error is that you have timestamps enabled in sequelize, but your actual table definitions in the DB do not contain a timestamp column.
When you do user.find it will just do SELECT user.*, which only takes the columns you actually have. But when you join, each column of the joined table will be a...
Is an index needed for a primary key in SQLite?
When an integer column is marked as a primary key in an SQLite table, should an index be explicitly created for it as well? SQLite does not appear to automatically create an index for a primary key column, but perhaps it indexes it anyway, given its purpose? (I will be searching on that column all t...
How to do an INNER JOIN on multiple columns
...nds flights either by the city name or the airport code, but the flights table only contains the airport codes so if I want to search by city I have to join on the airports table.
...
What's the difference between using INDEX vs KEY in MySQL?
...
There's no difference. They are synonyms.
From the CREATE TABLE manual entry:
KEY is normally a synonym for INDEX. The key attribute PRIMARY KEY can
also be specified as just KEY when given in a column definition. This was
implemented for compatibility with other database sy...
how to mysqldump remote db from local machine
...And change:
mysqldump -P 3310 -h localhost -u mysql_user -p database_name table_name
To:
mysqldump -P 3310 -h 127.0.0.1 -u mysql_user -p database_name table_name
(do not use localhost, it's one of these 'special meaning' nonsense that probably connects by socket rather then by port)
edit: we...