multiple-columns

I need to implement the following query SELECT * FROM friend WHERE ( friend.id1, friend.id2 ) NOT IN (SELECT id1, id2 FROM likes) but NOT IN can't be implemented on multiple columns. How do I write this query I'm not sure whether you think about: select * from friend f where not exists ( select 1 from likes l where f.id1 = l.id and f.id2 = l.id2 ) it works only if id1 is related with id1 and id2 with id2 not both. Erwin Brandstetter Another mysteriously unknown RDBMS. Your Syntax is perfectly fine in PostgreSQL. Other query styles may perform faster (especially the NOT EXISTS variant or a LEFT

Is it possible in pure CSS to lay out list elements to arbitrary number of columns, preserving the left-to-right order, as on this example? Yes, it should be theoretically possible. Since you want the flex items arranged in columns, #flex-container { flex-flow: column wrap; } But then the order of the elements would be preserved vertically (in columns). Since you want horizontally, they must be reordered: #flex-container > :nth-child(4n - 2) { order: 1; } #flex-container > :nth-child(4n - 1) { order: 2; } #flex-container > :nth-child(4n - 0) { order: 3; } And then we must force column breaks.

Given this dataframe: feature score searchTerm 0 a 0.534509 pizza 1 b 0.586020 pizza 2 c 0.588972 pizza 3 a 0.566261 chinese 4 b 0.572405 chinese 5 c 0.489369 chinese 6 a 0.499068 thai 7 b 0.431068 thai 8 c 0.441617 thai Feature is limited to ( a , b , c ) I want to pivot the dataframe into this: a b c searchTerm 0.534509 0.586020 0.588972 pizza 0.566261 0.572405 0.489369 chinese 0.499068 0.431068 0.441617 thai ... ... You can use pivot : df1 = df.pivot(index='searchTerm', columns='feature', values='score').reset_index() print (df1) feature searchTerm a b c 0 chinese 0.566261 0.572405 0.489369

The design I am working to has different backgrounds for alternate columns. Is it possible to set up different tiling backgrounds for each column, e.g. column:nth-child(n+1) {background:url(tile1.gif) repeat-x; } Or do I have to fall back on a huge background image that tiles every two columns? Unfortunately you cannot change the color of the columns: It is not possible to set properties/values on column boxes. For example, the background of a certain column box cannot be set and a column box has no concept of padding, margin or borders. From w3.org: 2. The multi-column model 来源： https:/

I am trying to do count distinct values based on multiple criteria. Sample data exercise included below. Table1 ╔════════╦════════╦══════╗ ║ Bug ID ║ Status ║ Test ║ ╠════════╬════════╬══════╣ ║ 1 ║ Open ║ w ║ ║ 2 ║ Closed ║ w ║ ║ 3 ║ Open ║ w ║ ║ 4 ║ Open ║ x ║ ║ 4 ║ Open ║ x ║ ║ 5 ║ Closed ║ x ║ ║ 5 ║ Closed ║ x ║ ║ 5 ║ Closed ║ y ║ ║ 6 ║ Open ║ z ║ ║ 6 ║ Open ║ z ║ ║ 6 ║ Open ║ z ║ ║ 7 ║ Closed ║ z ║ ║ 8 ║ Closed ║ z ║ ╚════════╩════════╩══════╝ Desired Query Results ╔══════╦═══════════╦════════════╗ ║ Test ║ Open Bugs ║ Total Bugs ║ ╠══════╬═══════════╬════════════╣ ║ w ║ 2 ║ 3 ║ ║ x ║ 1 ║

Say I have two tables in a MySQL Database. Table 1: ID Name 1 Jim 2 Bob 3 John Table 2: ID key value 1 address "X Street" 1 city "NY" 1 region "NY" 1 country "USA" 1 postal_code "" 1 phone "123456789" When selecting rows from the database, is there any way to join rows from the second table as columns to the first table? The desired result right from the MySQL query is: ID Name address city region country postal_code phone 1 Jim X Street NY NY USA NULL 123456789 2 Bob NULL NULL NULL NULL NULL NULL 3 John NULL NULL NULL NULL NULL NULL Thanks for any help! This type of data transformation is

I have to remove columns in my dataframe which has over 4000 columns and 180 rows.The conditions I want to set in to remove the column in the dataframe are: (i) Remove the column if there are less then two values/entries in that column (ii) Remove the column if there are no two consecutive(one after the other) values in the column. (iii) Remove the column having all values as NA. I have provided with conditions on which a column is to be deleted. The aim here is not just to find a column by its name like in "How do you delete a column in data.table?". I Illustrate as follows: A B C D E 0.018