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Large, persistent DataFrame in pandas
...le paths
in_csv = '../data/my_large.csv'
out_sqlite = '../data/my.sqlite'
table_name = 'my_table' # name for the SQLite database table
chunksize = 100000 # number of lines to process at each iteration
# columns that should be read from the CSV file
columns = ['molecule_id','charge','db','drugsnow'...
Insert current date in datetime format mySQL
...re the current time just use MYSQL's functions.
mysql_query("INSERT INTO `table` (`dateposted`) VALUES (now())");
If you need to use PHP to do it, the format it Y-m-d H:i:s so try
$date = date('Y-m-d H:i:s');
mysql_query("INSERT INTO `table` (`dateposted`) VALUES ('$date')");
...
Rails 4: List of available datatypes
... is not set to use :sql, then your schema.rb file wont be able to dump the table that uses types like :json. The schema will still be dumped for the tables that use default types but you'll see a comment for the table with special types like, "could not dump table...". Look here to set the schema_fo...
Alternate output format for psql
I am using PostgreSQL 8.4 on Ubuntu. I have a table with columns c1 through cN . The columns are wide enough that selecting all columns causes a row of query results to wrap multiple times. Consequently, the output is hard to read.
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Oracle “Partition By” Keyword
...ment for every employee record. (It is as if you're de-nomalising the emp table; you still return every record in the emp table.)
emp_no dept_no DEPT_COUNT
1 10 3
2 10 3
3 10 3 <- three because there are three "dept_no = 10" records
4 20 2
5 ...
Best way to check if UITableViewCell is completely visible
I have a UITableView with cells of different heights and I need to know when they are completely visible or not.
10 Answe...
What's the Hi/Lo algorithm?
...re out the next identifier value knowing we use hilo in this particular DB table?
– Vlad Mihalcea
Feb 7 '17 at 1:46
My...
How to load a tsv file into a Pandas DataFrame?
...od - it was very slow and failed indexing at the end. Instead, i used read_table(), which worked much faster and without the extra param.
– Yurik
Aug 15 '14 at 9:56
...
MySQL select one column DISTINCT, with corresponding other columns
...
try this query
SELECT ID, FirstName, LastName FROM table GROUP BY(FirstName)
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Which is faster/best? SELECT * or SELECT column1, colum2, column3, etc
... that SQL Server can access the data from indexes rather than querying the table data.
Here's a post I wrote about it: The real reason select queries are bad index coverage
It's also less fragile to change, since any code that consumes the data will be getting the same data structure regardless...