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SQL Joins Vs SQL Subqueries (Performance)?
...ies with Semijoin Transformations
Rewriting Subqueries as Joins
I have a table with 50000 elements, the result i was looking for was 739 elements.
My query at first was this:
SELECT p.id,
p.fixedId,
p.azienda_id,
p.categoria_id,
p.linea,
p.tipo,
p.nome
FROM prodotto p
WH...
MySQL get row position in ORDER BY
With the following MySQL table:
9 Answers
9
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MySQL Fire Trigger for both Insert and Update
...ossible to fire a mysql trigger for both the insert and update events of a table?
3 Answers
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LEFT JOIN vs. LEFT OUTER JOIN in SQL Server
... at the answer I left on this other SO question: SQL left join vs multiple tables on FROM line?.
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Smallest data URI image possible for a transparent image
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After playing around with different transparent GIFs, some are unstable and cause CSS glitches. For example, if you have an <img> and you use the tiniest transparent GIF possible, it works fine, however, if you then want your transparent GIF to have a background-image, then this is im...
How can I make SQL case sensitive string comparison on MySQL?
...y I have had luck in using varbinary instead of varchar for a field in ut8 table. HTH
– Andrew T
Jan 5 '15 at 19:54
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MySQL error 1449: The user specified as a definer does not exist
... ALTER statements
SELECT CONCAT("ALTER DEFINER=`youruser`@`host` VIEW ",
table_name, " AS ", view_definition, ";")
FROM information_schema.views
WHERE table_schema='your-database-name';
Copy and run the ALTER statements
How to change the definer for stored procedures
Example:
UPDATE `mysql`...
MySql Table Insert if not exist otherwise update
...ould not change. You do need to include all of the other columns from your table. You can use the VALUES() function to make sure the proper values are used when updating the other columns.
Here is your update re-written using the proper INSERT ... ON DUPLICATE KEY UPDATE syntax for MySQL:
INSERT I...
How to re-create database for Entity Framework?
... new project and create a new mdf. The mdf does not have to match your old tables, because were going to delete it. So create or copy an old one to the correct folder.
Open it in server explorer [double click the mdf from solution explorer]
Delete it in server explorer
Delete it from solution explor...
Relative frequencies / proportions with dplyr
...our depending on the version of dplyr:
dplyr 0.7.1: returns an ungrouped table: you need to group again by am
dplyr < 0.7.1: returns a grouped table, so no need to group again, although you might want to ungroup() for later manipulations
dplyr 0.7.1
mtcars %>%
count(am, gear) %>%
g...