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Remove Trailing Spaces and Update in Columns in SQL Server
I have trailing spaces in a column in a SQL Server table called Company Name .
13 Answers
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How is set() implemented?
...zation(s) that exploit this lack of values
So basically a set uses a hashtable as its underlying data structure. This explains the O(1) membership checking, since looking up an item in a hashtable is an O(1) operation, on average.
If you are so inclined you can even browse the CPython source code...
Finding duplicate values in MySQL
I have a table with a varchar column, and I would like to find all the records that have duplicate values in this column. What is the best query I can use to find the duplicates?
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Remove Primary Key in MySQL
I have the following table schema which maps user_customers to permissions on a live MySQL database:
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What is “the inverse side of the association” in a bidirectional JPA OneToMany/ManyToOne association
... the object, in this case the customer. The customer has no columns in the table to store the orders, so you must tell it where in the order table it can save this data (which happens via mappedBy).
Another common example are trees with nodes which can be both parents and children. In this case, th...
What are the differences between virtual memory and physical memory?
...perating system creates and deals with these mappings - utilizing the page table, among other data structures to maintain the mappings. Virtual memory mappings are always found in the page table or some similar data structure (in case of other implementations of virtual memory, we maybe shouldn't ca...
Can dplyr package be used for conditional mutating?
...for other better ways to handle the problem, here's another way using data.table:
require(data.table) ## 1.9.2+
setDT(df)
df[a %in% c(0,1,3,4) | c == 4, g := 3L]
df[a %in% c(2,5,7) | (a==1 & b==4), g := 2L]
Note the order of conditional statements is reversed to get g correctly. There's no co...
How to get all registered routes in Express?
...('/api/questions', questionsRoute);
I renamed the document.js file in apiTable.js and adapted it like this:
module.exports = function (baseUrl, routes) {
var Table = require('cli-table');
var table = new Table({ head: ["", "Path"] });
console.log('\nAPI for ' + baseUrl);
console....
MySql : Grant read only options?
...ns on database.
It depends on how you define "all read."
"Reading" from tables and views is the SELECT privilege. If that's what you mean by "all read" then yes:
GRANT SELECT ON *.* TO 'username'@'host_or_wildcard' IDENTIFIED BY 'password';
However, it sounds like you mean an ability to "see" ...
Can I have multiple primary keys in a single table?
Can I have multiple primary keys in a single table?
12 Answers
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