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When to use Common Table Expression (CTE)
I have begun reading about Common Table Expression and cannot think of a use case where I would need to use them. They would seem to be redundant as the same can be done with derived tables. Is there something I am missing or not understanding well? Can someone give me a simple example of limitati...
How to set a default value for an existing column
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This will work in SQL Server:
ALTER TABLE Employee ADD CONSTRAINT DF_SomeName DEFAULT N'SANDNES' FOR CityBorn;
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Difference between left join and right join in SQL Server [duplicate]
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Select * from Table1 left join Table2 ...
and
Select * from Table2 right join Table1 ...
are indeed completely interchangeable. Try however Table2 left join Table1 (or its identical pair, Table1 right join Table2) to see a difference....
mysql :: insert into table, data from another table?
...correct method. But, if someone looking to insert more extra column in the table then you can get it from the following:
INSERT INTO action_2_members (`campaign_id`, `mobile`, `email`, `vote`, `vote_date`, `current_time`)
SELECT `campaign_id`, `from_number`, 'example@domain.xyz', `received_msg`, `d...
postgresql - add boolean column to table set default
Is this proper postgresql syntax to add a column to a table with a default value of false
5 Answers
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jQuery delete all table rows except first
Using jQuery, how do I delete all rows in a table except the first? This is my first attempt at using index selectors. If I understand the examples correctly, the following should work:
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How to change a table name using an SQL query?
How can I in change the table name using a query statement?
10 Answers
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How to drop column with constraint?
... problematic DEFAULT constraint, after that you can drop the column
alter table tbloffers drop constraint [ConstraintName]
go
alter table tbloffers drop column checkin
But the error may appear from other reasons - for example the user defined function or view with SCHEMABINDING option set for th...
How can you represent inheritance in a database?
...e SQL Entity-Attribute-Value antipattern. This is a brief overview:
Single Table Inheritance (aka Table Per Hierarchy Inheritance):
Using a single table as in your first option is probably the simplest design. As you mentioned, many attributes that are subtype-specific will have to be given a NULL v...
How to remove a lua table entry by its key?
I have a lua table that I use as a hashmap, ie with string keys :
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