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Inner join vs Where
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No! The 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 * FRO...
Java HashMap performance optimization / alternative
...h code as mmyers and rsp suggest is better. In my case my solution is acceptable and I wanted to highlight the fact that the arrays must be sorted for hashCode() to work.
– nash
Nov 19 '09 at 17:00
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Can I combine :nth-child() or :nth-of-type() with an arbitrary selector?
...ot match) an arbitrary selector ? For example, I want to select every odd table row, but within a subset of the rows:
7 An...
What is the difference between a stored procedure and a view?
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A view represents a virtual table. You can join multiple tables in a view and use the view to present the data as if the data were coming from a single table.
A stored procedure uses parameters to do a function... whether it is updating and inserting ...
What are the uses for Cross Join?
...t
size,
color
from
sizes CROSS JOIN colors
Maybe you want a table that contains a row for every minute in the day, and you want to use it to verify that a procedure has executed each minute, so you might cross three tables:
select
hour,
minute
from
hours CROSS JOIN minute...
Convert objective-c typedef to its string equivalent
...ms are really just glorified integer constants. You'll have to generate a table of names yourself (or with some preprocessor abuse). For example:
// In a header file
typedef enum FormatType {
JSON,
XML,
Atom,
RSS
} FormatType;
extern NSString * const FormatType_toString[];
// In...
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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Entity Framework: table without primary key
...That's fine, I suppose, but keep in mind that the OP asked about mapping a table without a primary key, not a view. The answer is still the same. Working around the EF's need to have a PK on tables is a bad idea from the standpoint of manageability, data integrity, and performance.
Some have comm...
LAST_INSERT_ID() MySQL
...hat I think must be quite easy. I need to return the LAST INSERTED ID from table1 when I run the following MySql query:
11 ...
How to make Sequelize use singular table names
I have an model called User but Sequelize looks for the table USERS whenever I am trying to save in the DB. Does anyone know how to set Sequelize to use singular table names? Thanks.
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