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SQL Server Insert if not exists
...
instead of below Code
BEGIN
INSERT INTO EmailsRecebidos (De, Assunto, Data)
VALUES (@_DE, @_ASSUNTO, @_DATA)
WHERE NOT EXISTS ( SELECT * FROM EmailsRecebidos
WHERE De = @_DE
AND Assunto = @_ASSUNTO
AND Data = @_D...
Index on multiple columns in Ruby on Rails
...columns in sequence starting at the beginning. i.e. if you index on [:user_id, :article_id], you can perform a fast query on user_id or user_id AND article_id, but NOT on article_id.
Your migration add_index line should look something like this:
add_index :user_views, [:user_id, :article_id]
...
SQL DROP TABLE foreign key constraint
...ver 2005 and up):
SELECT *
FROM sys.foreign_keys
WHERE referenced_object_id = object_id('Student')
and if there are any, with this statement here, you could create SQL statements to actually drop those FK relations:
SELECT
'ALTER TABLE [' + OBJECT_SCHEMA_NAME(parent_object_id) +
'].['...
Remove Identity from a column in a table
We have a 5GB table (nearly 500 million rows) and we want to remove the identity property on one of the column, but when we try to do this through SSMS - it times out.
...
NullPointerException accessing views in onCreate()
...tion is to move the code to the fragment onCreateView(), calling findViewById() on the inflated fragment layout rootView:
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, cont...
Inner join vs Where
...he same execution plan, look at these two tables:
CREATE TABLE table1 (
id INT,
name VARCHAR(20)
);
CREATE TABLE table2 (
id INT,
name VARCHAR(20)
);
The execution plan for the query using the inner join:
-- with inner join
EXPLAIN PLAN FOR
SELECT * FROM table1 t1
INNER JOIN table2 t2 ...
How do I use variables in Oracle SQL Developer?
...
I am using the SQL-Developer in Version 3.2. The other stuff didn't work for me, but this did:
define value1 = 'sysdate'
SELECT &&value1 from dual;
Also it's the slickest way presented here, yet.
(If you omit the "define"-part you'll be prompted for that value)
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org.hibernate.MappingException: Could not determine type for: java.util.List, at table: College, for
...
You are using field access strategy (determined by @Id annotation). Put any JPA related annotation right above each field instead of getter property
@OneToMany(targetEntity=Student.class, mappedBy="college", fetch=FetchType.EAGER)
private List<Student> students;
...
How do I find the most recent git commit that modified a file?
...o know the last time a file was modified no matter the branch, you can consider all branches by adding the --all option.
– K. C.
Aug 13 '15 at 8:00
add a comment
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URL rewriting with PHP
...RewriteEngine on
RewriteRule ^/?Some-text-goes-here/([0-9]+)$ /picture.php?id=$1
This will tell Apache to enable mod_rewrite for this folder, and if it gets asked a URL matching the regular expression it rewrites it internally to what you want, without the end user seeing it. Easy, but inflexible,...