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When should I use Kruskal as opposed to Prim (and vice versa)?
...c.
If you implement both Kruskal and Prim, in their optimal form : with a union find and a finbonacci heap respectively, then you will note how Kruskal is easy to implement compared to Prim.
Prim is harder with a fibonacci heap mainly because you have to maintain a book-keeping table to record the...
Rename a table in MySQL
Renaming a table is not working in MySQL
16 Answers
16
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Update statement with inner join on Oracle
...sn't valid in Oracle. You can do this:
UPDATE table1 SET table1.value = (SELECT table2.CODE
FROM table2
WHERE table1.value = table2.DESC)
WHERE table1.UPDATETYPE='blah'
AND EXISTS (SELECT table2.CODE
FROM table2
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Python 3 ImportError: No module named 'ConfigParser'
I am trying to pip install the MySQL-python package, but I get an ImportError .
18 Answers
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How do you create a read-only user in PostgreSQL?
I'd like to create a user in PostgreSQL that can only do SELECTs from a particular database. In MySQL the command would be:
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MongoDB vs. Cassandra [closed]
...sandra: they are not using Cassandra for persisting tweets, they use still MySQL here (engineering.twitter.com/2010/07/cassandra-at-twitter-today.html). Ok, but I can imagine that they still store lots of data for other purposes in Cassandra.
– H6.
Jan 13 '12 a...
SQL WHERE ID IN (id1, id2, …, idn)
... But how would you pass the list of ids that you need? (Seeing you can't select a range or something like that).
– raam86
Oct 18 '16 at 14:32
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How do I check if a SQL Server text column is empty?
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Actually, you just have to use the LIKE operator.
SELECT * FROM mytable WHERE mytextfield LIKE ''
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How can I temporarily disable a foreign key constraint in MySQL?
Is it possible to temporarily disable constraints in MySQL?
10 Answers
10
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SQL join: selecting the last records in a one-to-many relationship
... want to get a list of all customers along with their last purchase in one SELECT statement. What is the best practice? Any advice on building indexes?
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