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Why are ToLookup and GroupBy different?
...happens when you call ToLookup on an object representing a remote database table with a billion rows in it?
The billion rows are sent over the wire, and you build the lookup table locally.
What happens when you call GroupBy on such an object?
A query object is built; end of story.
When that quer...
Difference between @OneToMany and @ElementCollection?
...ring> strings;
Simpler, isn't it? Note that you can still control the table and column names using @CollectionTable annotation.
See also:
Java Persistence/ElementCollection
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The case against checked exceptions
...with it.
This would be clearer with a counter-case. Imagine I'm writing a table API. I have the table model somewhere with an API including this method:
public RowData getRowData(int row)
Now as an API programmer I know there will be cases where some client passes in a negative value for the ro...
Explanation of JSONB introduced by PostgreSQL
...me operation at a json typed value)
When jsonb will be available with a stable release, there will be two major use cases, when you can easily select between them:
If you only work with the JSON representation in your application, PostgreSQL is only used to store & retrieve this representati...
what is the difference between OLE DB and ODBC data sources?
...nt times.
ODBC
ODBC is an industry-wide standard interface for accessing table-like data. It was primarily developed for databases and presents data in collections of records, each of which is grouped into a collection of fields. Each field has its own data type suitable to the type of data it con...
Remove non-utf8 characters from string
... @Alliswell If I'm not mistaken <0x1a>, although not printable character, is a perfectly valid UTF-8 sequence. You might have issues with non-printable characters? Check this: stackoverflow.com/questions/1176904/…
– Frosty Z
Mar 12 '19 at 8:...
java.net.ConnectException: Connection refused
...t also helped me, the test connection was succesfull but couldn't show any tables data.
– Damien Christophe
Aug 13 '19 at 7:52
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Why can't C# interfaces contain fields?
...
The virtual keyword is implemented in .NET with methods and a so-called v-table, an array of method pointers. The override keyword fills the v-table slot with a different method pointer, overwriting the one produced by the base class. Properties, events and indexers are implemented as methods und...
Binary Data in MySQL [closed]
...
For a table like this:
CREATE TABLE binary_data (
id INT(4) NOT NULL AUTO_INCREMENT PRIMARY KEY,
description CHAR(50),
bin_data LONGBLOB,
filename CHAR(50),
filesize CHAR(50),
filetype CHAR(50)
);
Here is...
How to resize a tableHeaderView of a UITableView?
I'm having trouble resizing a tableHeaderView. It simple doesn't work.
19 Answers
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