convert the NULL values with empty string by wrapping it in COALESCE SELECT CONCAT(COALESCE(`affiliate_name`,”),’-‘,COALESCE(`model`,”),’-‘,COALESCE(`ip`,”),’-‘,COALESCE(`os_type`,”),’-‘,COALESCE(`os_version`,”)) AS device_name FROM devices
I previously said that this couldn’t be done, but I was wrong. I ended up needing something like this myself so I looked around, and discovered that server-side prepared statements let you build and execute arbitrary SQL statements from strings. Here is an example I just did to prove the concept: set @query := ( … Read more
Seems like you can use the same Array.prototype.slice.call that makes the args array-like object become an array. (See here) var inputs = document.getElementsByTagName(‘input’); var selects = document.getElementsByTagName(‘select’); inputs = Array.prototype.slice.call(inputs); selects = Array.prototype.slice.call(selects); var res = inputs.concat(selects); alert(res.length);
var mystr = “Doe”; mystr = “John ” + mystr; Wouldn’t this work for you?
The aliases you give are for the output of the query – they are not available within the query itself. You can either repeat the expression: SELECT neededfield, CONCAT(firstname, ‘ ‘, lastname) as firstlast FROM users WHERE CONCAT(firstname, ‘ ‘, lastname) = “Bob Michael Jones” or wrap the query SELECT * FROM ( SELECT neededfield, … Read more
You can concatenate strings a number of ways: let a = “Hello” let b = “World” let first = a + “, ” + b let second = “\(a), \(b)” You could also do: var c = “Hello” c += “, World” I’m sure there are more ways too. Bit of description let creates a … Read more
A very high level difference is that merge() is used to combine two (or more) dataframes on the basis of values of common columns (indices can also be used, use left_index=True and/or right_index=True), and concat() is used to append one (or more) dataframes one below the other (or sideways, depending on whether the axis option … Read more
a String is immutable, meaning you cannot change a String in Java. concat() returns a new, concatenated, string. String s = “TEST”; String s2 = s.trim(); String s3 = s.concat(“ING”); System.out.println(“S = “+s); System.out.println(“S2 = “+s2); System.out.println(“S3 = “+s3);
If you want a new object with two keys, Object1 and Object2, you can do: JSONObject Obj1 = (JSONObject) jso1.get(“Object1”); JSONObject Obj2 = (JSONObject) jso2.get(“Object2”); JSONObject combined = new JSONObject(); combined.put(“Object1”, Obj1); combined.put(“Object2”, Obj2); If you want to merge them, so e.g. a top level object has 5 keys (Stringkey1, ArrayKey, StringKey2, StringKey3, StringKey4), I … Read more
Given that all the dataframes have the same columns, you can simply concat them: import pandas as pd df = pd.concat(list_of_dataframes)