select

问题 I have a database which holds different locations, each of which has its own longitude and latitude variable. I want to be able to use a distance function I made that returns the distance between two longitudes and latitudes in my WHERE statement. So I am looking for the distance between two points and it pass the WHERE statement if it is less than the radius I am searching. distance function: function distance($lat1, $lon1, $lat2, $lon2) { $theta = $lon1 - $lon2; $dist = sin(deg2rad($lat1))

问题 I am looking for a method to return the results of an SQLite query as a single string for use in an internal trigger. Something like Python's 'somestring'.join() method. Table: foo id | name 1 | "foo" 2 | "bar" 3 | "bro" Then a select statement: MAGIC_STRING_CONCAT_FUNCTION(SELECT id FROM foo,","); To return "1,2,3" 回答1: You're looking for the group_concat function: group_concat((SELECT id FROM foo), ","); The following is the description of the function group_concat from the documentation:

问题 My MySQL table has below records, ID Name Account ----------------------------------------- 1 ABC PQR 2 DEF PQR 3 ABC PQR 4 XYZ ABC 5 DEF PQR 6 DEF ABC I am looking for an output like ID Name Account Duplicate Sr No. ----------------------------------------- 1 ABC PQR 1 2 DEF PQR 1 3 ABC PQR 2 4 XYZ ABC 1 5 DEF PQR 2 6 DEF ABC 1 Here i mean that each duplicate should have a Sr Number or number the duplicates. Name : ABC and Account : PQR when repeated in the table, there is an increment in

问题 I'am building a small webapplication for personal business purpose. I have come far from looking around and looking how to program a webapplication. So I can added reservations and edit them and also delete them. The last days I have been looking how to save a date into Mysql database and how to show it in the webapplication. For so far its working but its not showing in the right format. If you see the attachment Date sample I want the date like this "30-04-2020" and not like "2020-04-30".

问题 I currently have a select() statement configured to keep track of two UDP sockers. I send perhaps 10 - 20 messages a second at one general data socket, which is this interpreted as I expected. However, once I hit around 1024 messages, I get the notice: talker: socket: Too many open files talker: failed to bind socket This is logical to me, since ulimit -n shows a max of 1024 open files for this user. However, why are there all of these open files? With UDP, there is no connection made, so I

问题 I wrote a SELECT performing a UNION and in each UNION part using some JOINs. The tables, which are joined have partly the same column identifiers. And if a "SELECT *" is performed, ORACLE decides to display the internal column names instead of the "real" column names. To show the effect I created two tables (with partly similar column identifiers, "TID" and "TNAME") and filled them with some data: create table table_one (tid number(10), tname varchar2(10), t2id number(10)); create table table

问题 I'm writing a SQL statement for my MS Access database, and the purpose is to count values from 3 different queries, so I tried this way: SELECT(query1 + query2 + query3) AS Qtd Each query returns an unique value from an aggregate function count, i.e, query1 = SELECT Count(something) FROM Table WHERE... Everything should work fine, but MS Access demands a FROM clause. When I put a table in that query (not changing the SELECT statement above), I end up with tones of rows and each row the result

问题 I'm writing a SQL statement for my MS Access database, and the purpose is to count values from 3 different queries, so I tried this way: SELECT(query1 + query2 + query3) AS Qtd Each query returns an unique value from an aggregate function count, i.e, query1 = SELECT Count(something) FROM Table WHERE... Everything should work fine, but MS Access demands a FROM clause. When I put a table in that query (not changing the SELECT statement above), I end up with tones of rows and each row the result

问题 After selecting an option from drop-down. I am trying to get that option displayed in the console. below is my code. But I get "//[[[[ChromeDriver: chrome on WINDOWS (d5a01776981da5dacfeb89dbbc2e6b52)] -> xpath: //*[@name='airline']]].// -> tag name: option]" The tag name is option for dropdown options. I have tried all solutions of selectByXXXX. but nothing seems to work. what would be the right code ? //airline preference { Select airline = new Select (driver.find Element(By.name("airline")

问题 I am trying to select certain customers from a contacts table if they do not have a guardian listed. ClientId | ContactId | Guardian 123 | 1 | Y 123 | 2 | N 123 | 3 | N 456 | 4 | N 456 | 5 | N 456 | 6 | N Desired output: ClientId | ContactId | Guardian 456 | 4 | N 456 | 5 | N 456 | 6 | N So my goal is that Client 456 would show up in my query results, but not Client 123. I have written the following: select * from Contacts where Guardian <> (case when Guardian = 'Y' then Guardian else '' end)