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IEnumerable vs List - What to Use? How do they work?
... and possibly optimize the program. Remember how LINQ doesn't generate the SQL to query the database until you enumerate it? Consider this:
public IEnumerable<Animals> AllSpotted()
{
return from a in Zoo.Animals
where a.coat.HasSpots == true
select a;
}
public IEnum...
How do I select an entire row which has the largest ID in the table?
...ow profiles and it appears our solutions have the same performance using MySQL. For my own knowledge, do you know what DBMS has poorer performance for subselects?
– unutbu
Feb 7 '14 at 20:08
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What does collation mean?
What does collation mean in SQL, and what does it do?
9 Answers
9
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How to add 'ON DELETE CASCADE' in ALTER TABLE statement
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Just tested in SqlServer, but possible you have to chance go with semi-colon as in postgres and SqlServer itself. But the remain core codes are sql standar. Test with semi-colons, I just changed it
– David Silva-Barrer...
Inner join vs Where
... I find it much easier to comprehend FOR INNER JOINS than the SQL-92 syntax. Your mileage may vary.
– Craig Trader
Sep 23 '08 at 17:39
27
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Limiting the number of records from mysqldump?
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As skaffman says, use the --where option:
mysqldump --opt --where="1 limit 1000000" database
Of course, that would give you the first million rows from every table.
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Why shouldn't I use mysql_* functions in PHP?
What are the technical reasons for why one shouldn't use mysql_* functions? (e.g. mysql_query() , mysql_connect() or mysql_real_escape_string() )?
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Closing Database Connections in Java
...t ps = null;
ResultSet rs = null;
try {
// Do stuff
...
} catch (SQLException ex) {
// Exception handling stuff
...
} finally {
if (rs != null) {
try {
rs.close();
} catch (SQLException e) { /* ignored */}
}
if (ps != null) {
try {
...
Update a record without first querying?
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You can also use direct SQL against the database using the context of the datastore. Example:
dataEntity.ExecuteStoreCommand
("UPDATE items SET itemstatus = 'some status' WHERE id = 123 ");
For performance reasons, you may want to pass in var...
How should a model be structured in MVC? [closed]
...me, Domain Objects are completely unaware of storage - neither from where (SQL database, REST API, text file, etc.) nor even if they get saved or retrieved.
Data Mappers
These objects are only responsible for the storage. If you store information in a database, this would be where the SQL lives. Or...