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SQLAlchemy: Creating vs. Reusing a Session
Just a quick question: SQLAlchemy talks about calling sessionmaker() once but calling the resulting Session() class each time you need to talk to your DB. For me that means the second I would do my first session.add(x) or something similar, I would first do
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When to use a key/value store such as Redis instead/along side of a SQL database?
...tures offers versatility to many other scenarios.
Redis, however, isn't NoSQL replacement for classic relational databases since it doesn't support many standard features of RDBMS world such as querying of your data which might slow it down. Replacement are rather document databases like MongoDB or...
conditional unique constraint
...uplicate key value is (9999).
Note: the filtered index was introduced in SQL Server 2008. For earlier versions of SQL Server, please see this answer.
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Removing duplicate rows from table in Oracle
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You should do a small pl/sql block using a cursor for loop and delete the rows you don't want to keep. For instance:
declare
prev_var my_table.var1%TYPE;
begin
for t in (select var1 from my_table order by var 1) LOOP
-- if previous var equal cur...
How do you perform a left outer join using linq extension methods
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True, Entity Framework and Linq to SQL both require that since they can't easily do the Single check amidst a join. SingleOrDefault however is a more "correct" way to demonstrate this IMO.
– Ocelot20
Feb 3 '15 at 16:19
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Kill a postgresql session/connection
How can I kill all my postgresql connections?
20 Answers
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What is the difference between IQueryable and IEnumerable?
...rties in particular—one that points to a query provider (e.g., a LINQ to SQL provider) and another one pointing to a query expression representing the IQueryable<T> object as a runtime-traversable abstract syntax tree that can be understood by the given query provider (for the most part, you...
Importing a CSV file into a sqlite3 database table using Python
I have a CSV file and I want to bulk-import this file into my sqlite3 database using Python. the command is ".import .....". but it seems that it cannot work like this. Can anyone give me an example of how to do it in sqlite3? I am using windows just in case.
Thanks
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How to find all the tables in MySQL with specific column names in them?
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@Echo - you can always play with mysqldump with --skip-extended-insert and then grep through the file... dirty but strangely satifying :)
– Ken
Oct 20 '11 at 17:35
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What is Full Text Search vs LIKE
I just read a post mentioning "full text search" in SQL.
6 Answers
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