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How to reorder data.table columns (without copying)
I'd like to reorder columns in my data.table x , given a character vector of column names, neworder :
2 Answers
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How to write lists inside a markdown table?
Can one create a list (bullets, numbered or not) inside a markdown table.
6 Answers
6
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MySQL table is marked as crashed and last (automatic?) repair failed
I was repairing this table suddenly server hanged and when I returned back all tables are ok but this one showing 'in use' and when I try to repair it doesn't proceed.
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Should each and every table have a primary key?
I'm creating a database table and I don't have a logical primary key assigned to it. So, I'm thinking about leaving it without a primary key, but I'm feeling a bit guilty about it. Should I?
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What is the dual table in Oracle?
I've heard people referring to this table and was not sure what it was about.
14 Answers
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You can't specify target table for update in FROM clause
I have a simple mysql table:
11 Answers
11
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Tables instead of DIVs [duplicate]
Under what conditions should you choose tables instead of DIVs in HTML coding?
24 Answers
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JOIN queries vs multiple queries
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if you are joining 3 or more tables on different keys, often databases (i.e. mysql) can only use one index per table, meaning maybe one of the joins will be fast (and use an index) whereas the others will be extremely slow. For multiple queries, you can ...
How to use index in select statement?
Lets say in the employee table, I have created an index(idx_name) on the emp_name column of the table.
8 Answers
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conditional unique constraint
...unt > 0.
http://msdn.microsoft.com/en-us/library/ms188258.aspx
CREATE TABLE CheckConstraint
(
Id TINYINT,
Name VARCHAR(50),
RecordStatus TINYINT
)
GO
CREATE FUNCTION CheckActiveCount(
@Id INT
) RETURNS INT AS BEGIN
DECLARE @ret INT;
SELECT @ret = COUNT(*) FROM CheckConstraint WHER...