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How can I safely encode a string in Java to use as a filename?
...ot something to copy and paste.)
char fileSep = '/'; // ... or do this portably.
char escape = '%'; // ... or some other legal char.
String s = ...
int len = s.length();
StringBuilder sb = new StringBuilder(len);
for (int i = 0; i < len; i++) {
char ch = s.charAt(i);
if (ch < ' ' || c...
How do you change the datatype of a column in SQL Server?
... varchar(50) to a nvarchar(200) . What is the SQL command to alter this table?
8 Answers
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Get the last inserted row ID (with SQL statement) [duplicate]
I want to get the new created ID when you insert a new record in table.
3 Answers
3
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UITableView - scroll to the top
In my table view I have to scroll to the top. But I cannot guarantee that the first object is going to be section 0, row 0. May be that my table view will start from section number 5.
...
How to efficiently build a tree from a flat structure?
...
Store IDs of the objects in a hash table mapping to the specific object. Enumerate through all the objects and find their parent if it exists and update its parent pointer accordingly.
class MyObject
{ // The actual object
public int ParentID { get; set; ...
How to deal with page breaks when printing a large HTML table
I have a project which requires printing an HTML table with many rows.
12 Answers
12
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Using IQueryable with Linq
...tabase, with many ORM systems, you have the option of fetching data from a table in two ways, one which returns IEnumerable<T>, and one which returns an IQueryable<T>. Say, for example, you have a Products table, and you want to get all of the products whose cost is >$25.
If you do:...
mmap() vs. reading blocks
...r random access, especially if your access patterns are sparse and unpredictable.
Memory maps allow you to keep using pages from the cache until you are done. This means that if you use a file heavily for a long period of time, then close it and reopen it, the pages will still be cached. With read...
When to add what indexes in a table in Rails
... end of the index.
If you have a has_many :through relationship, your join table should have a unique index on both properties involved in the join as a compound key.
If you fetch a record directly using a unique identifier such as username or email, that should be a unique index.
If you fetch sets ...
Rails has_and_belongs_to_many migration
...
You need to add a separate join table with only a restaurant_id and user_id (no primary key), in alphabetical order.
First run your migrations, then edit the generated migration file.
Rails 3
rails g migration create_restaurants_users_table
Rails 4:
...