![]() Key1 int primary key not null identity(1,1), You may want to do some research for the version of SQL you are using!):Ĭreatetable.sql create table linkedlist00 ( Here's some actual code I've prepared (all actual code worked on MSSQL. This makes the best method to enter many entries at a time, then go back and set the foreign keys accordingly (or build a GUI that just does that for you) After you enter the second column, you can go back and set key2 of the first column to the primary key of the second column. When you first enter a column in for the table, you'll need to make sure key2 is set to null or you'll get an error. Key2 from col2 is set to null because it doesn't point to anything key2 is a foreign key leading to the key1 of col2 So your columns will link something link something like this Key2 is a foreign key linking to itself in the next column. The best way I've found so far is to create a single table for the linked list using the following format (this is pseudo code): This is something I've been trying to figure out for a while myself. Probably not what you're asking for here though. If you have many lists, a quick way to serialise and deserialise your list to text/binary, and you only ever want to store and retrieve the entire list, then store the entire list as a single value in a single column. This can be relatively easily implemented in a stored proc. Then you need to iterative logic in the retrieval of the list in order to get the items in order. If you want to perform lots of manipulations on the list and not many retrievals you may prefer to have an ID column pointing to the next item in the list, instead of using a position column. However, this requires a little more effort to work out when to increment the following elements, so you lose simplicity but gain performance if you will have many inserts.ĭepending on your requirements other options might appeal, such as: Since operations on the list can require multiple commands (eg an insert will require an INSERT and an UPDATE), ensure you always perform the commands within a transaction.Ī variation of this simple option is to have position incrementing by some factor for each item, say 100, so that when you perform an INSERT you don't always need to renumber the position of the following elements. Insert into linked_list (list_id, position, data) Update linked_list set position = position + 1 where position >= 3 and list_id = 1 So to insert an item into list 1 at index 3: begin transaction To manipulate the list just update the position and then insert/delete records as needed. create table linked_listĪlter table linked_list add primary key ( list_id, position ) Then you can use ORDER BY on the position column to retrieve in the desired order. Once you've set the Write_Output_To_File parameter to "y" you can run Words with a command like will generate a file called WORD.out that you can open up as a text file to rename it.The simplest option would be creating a table with a row per list item, a column for the item position, and columns for other data in the item. You are entering "y" or "n" about whether to change the current parameter setting. The image below shows this.ĭon't get mixed up by thinking that you can enter "y" or "n" as the parameter setting. You will be presented with each parameter sequentially and you can enter "n" to keep the current parameter setting (which could be set to either yes or no) or "y" to change the parameter setting (to either yes or no).Īfter you go through all the parameters, you'll be asked if you want to save the parameter changes. Then enter "#" to change the parameters and mode of the program and hit enter. William Whitaker's WORDS beginning interface While running Words in a Windows command line, enter "#" to change the parameters. What I learned that I had to do was this: I didn't think to check Github first, but there is some very good information at the William Whitaker WORDS project site, including a user guide here: fireman's bucket) įrom standard output, you can also redirect the results to a file from python, you might use commands or subprocess in Java you might use exec() or ProcessBuilder, for example: ProcessBuilder pb = new ProcessBuilder("./words", "amo", "amas", "amat") Love, like fall in love with be fond of have a tendency to īucket water bucket (esp. words amo amasĪmo, amare, amavi, amatus V (1st) ![]() ![]() As a concrete example using bash, instead of reading from which always writes to WORD.OUT, execute words followed by a list of words on standard input the results appear on standard output: $. The exact details depend your chosen environment. William Whitaker's Words includes an interactive command line interpreter, but it looks like you want to control it from another program using command-line mode.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |