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LINQ to SQL - Left Outer Join with multiple join conditions
...g.Where(f => f.otherid == 17).DefaultIfEmpty()
where p.companyid == 100
select f.value
Or you could use a subquery:
from p in context.Periods
join f in context.Facts on p.id equals f.periodid into fg
from fgi in (from f in fg
where f.otherid == 17
select f).DefaultIfE...
How do I get a list of column names from a psycopg2 cursor?
I would like a general way to generate column labels directly from the selected column names, and recall seeing that python's psycopg2 module supports this feature.
...
Insertion Sort vs. Selection Sort
I am trying to understand the differences between Insertion Sort and Selection Sort.
20 Answers
...
IN clause and placeholders
...mes = { "name1", "name2" }; // do whatever is needed first
String query = "SELECT * FROM table"
+ " WHERE name IN (" + makePlaceholders(names.length) + ")";
Cursor cursor = mDb.rawQuery(query, names);
Just make sure to pass exactly as many values as places. The default maximum limit of host pa...
How to find the Number of CPU Cores via .NET/C#?
...ors:
foreach (var item in new System.Management.ManagementObjectSearcher("Select * from Win32_ComputerSystem").Get())
{
Console.WriteLine("Number Of Physical Processors: {0} ", item["NumberOfProcessors"]);
}
Cores:
int coreCount = 0;
foreach (var item in new System.Management.ManagementObjec...
MySQL vs MongoDB 1000 reads
...s://github.com/webcaetano/mongo-mysql
10 rows
mysql insert: 1702ms
mysql select: 11ms
mongo insert: 47ms
mongo select: 12ms
100 rows
mysql insert: 8171ms
mysql select: 10ms
mongo insert: 167ms
mongo select: 60ms
1000 rows
mysql insert: 94813ms (1.58 minutes)
mysql select: 13ms
mongo inser...
Mongoose, Select a specific field with find
I'm trying to select only a specific field with
8 Answers
8
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PostgreSQL - max number of parameters in “IN” clause?
...
explain select * from test where id in (values (1), (2));
QUERY PLAN
Seq Scan on test (cost=0.00..1.38 rows=2 width=208)
Filter: (id = ANY ('{1,2}'::bigint[]))
But if try 2nd query:
explain select * from test where id = an...
mysql :: insert into table, data from another table?
...
INSERT INTO action_2_members (campaign_id, mobile, vote, vote_date)
SELECT campaign_id, from_number, received_msg, date_received
FROM `received_txts`
WHERE `campaign_id` = '8'
share
|
imp...
How can you determine how much disk space a particular MySQL table is taking up?
...
For a table mydb.mytable run this for:
BYTES
SELECT (data_length+index_length) tablesize
FROM information_schema.tables
WHERE table_schema='mydb' and table_name='mytable';
KILOBYTES
SELECT (data_length+index_length)/power(1024,1) tablesize_kb
FROM information_schema....