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MYSQL Dump only certain rows
I am trying to do a mysql dump of a few rows in my database. I can then use the dump to upload those few rows into another database. The code I have is working, but it dumps everything. How can I get mysqldump to only dump certain rows of a table?
...
How to work with Git branches and Rails migrations
...'On branch ','').chomp
%>
defaults: &defaults
pool: 5
adapter: mysql2
encoding: utf8
reconnect: false
username: root
password:
host: localhost
<% environments.each do |environment| %>
<%= environment %>:
<<: *defaults
database: <%= [ database_prefix...
Getting raw SQL query string from PDO prepared statements
... prepare(), and the parameters are sent separately when you do execute(). MySQL's general query log does show the final SQL with values interpolated after you execute(). Below is an excerpt from my general query log. I ran the queries from the mysql CLI, not from PDO, but the principle is the sam...
Return a value if no rows are found in Microsoft tSQL
...ight be a dead horse, another way to return 1 row when no rows exist is to UNION another query and display results when non exist in the table.
SELECT S.Status, COUNT(s.id) AS StatusCount
FROM Sites S
WHERE S.Id = @SiteId
GROUP BY s.Status
UNION ALL --UNION BACK ON TABLE WITH NOT EXISTS
SELECT 'N/...
+ operator for array in PHP?
...and array)
)
So the logic of + is equivalent to the following snippet:
$union = $array1;
foreach ($array2 as $key => $value) {
if (false === array_key_exists($key, $union)) {
$union[$key] = $value;
}
}
If you are interested in the details of the C-level implementation head t...
How to randomly select rows in SQL?
...to your question:
Selecting a random row in SQL
Select a random row with MySQL:
SELECT column FROM table
ORDER BY RAND()
LIMIT 1
Select a random row with PostgreSQL:
SELECT column FROM table
ORDER BY RANDOM()
LIMIT 1
Select a random row with Microsoft SQL Server:
SELECT TOP 1 column FROM ta...
Is having an 'OR' in an INNER JOIN condition a bad idea?
...LECT *
FROM maintable m
JOIN othertable o
ON o.parentId = m.id
UNION
SELECT *
FROM maintable m
JOIN othertable o
ON o.id = m.parentId
, each of them being an equijoin, however, SQL Server's optimizer is not smart enough to see it in the query you wrote (though they are logi...
How to use Git properly with Xcode?
...add this line to a .gitattributes file:
*.pbxproj text -crlf -diff -merge=union
Then git will always take both sides of a merge for the .pbxproject files, having the same effect as the script I provided only without any extra work.
Lastly, here is my complete .gitignore file, showing what I do h...
Can someone give an example of cosine similarity, in a very simple, graphical way?
...e1)
counter2 = Counter(iterable2)
all_items = set(counter1.keys()).union(set(counter2.keys()))
vector1 = [counter1[k] for k in all_items]
vector2 = [counter2[k] for k in all_items]
return vector1, vector2
def cosim(v1, v2):
dot_product = sum(n1 * n2 for n1, n2 in zip(v1, v2)...
C++ protobuf使用入门实例 - C/C++ - 清泛网 - 专注C/C++及内核技术
...singleton enumeration to represent the null value for the
// `Value` type union.
//
// The JSON representation for `NullValue` is JSON `null`.
enum TestNullValue {
// Null value.
NULL_VALUE = 0;
}
// `ListValue` is a wrapper around a repeated field of values.
//
// The JSON represen...