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How do you list all triggers in a MySQL database?
...ll triggers is:
show triggers;
or you can access the INFORMATION_SCHEMA table directly by:
select trigger_schema, trigger_name, action_statement
from information_schema.triggers
You can do this from version 5.0.10 onwards.
More information about the TRIGGERS table is here.
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How to do a FULL OUTER JOIN in MySQL?
....
For a code SAMPLE transcribed from this SO question you have:
with two tables t1, t2:
SELECT * FROM t1
LEFT JOIN t2 ON t1.id = t2.id
UNION
SELECT * FROM t1
RIGHT JOIN t2 ON t1.id = t2.id
The query above works for special cases where a FULL OUTER JOIN operation would not produce any duplicat...
trying to align html button at the center of the my page [duplicate]
...
I've really taken recently to display: table to give things a fixed size such as to enable margin: 0 auto to work. Has made my life a lot easier. You just need to get past the fact that 'table' display doesn't mean table html.
It's especially useful for responsiv...
How do you check “if not null” with Eloquent?
...
If you wanted to use the DB facade:
DB::table('table_name')->whereNotNull('sent_at')->get();
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Hex transparency in colors [duplicate]
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Here's a correct table of percentages to hex values. E.g. for 50% white you'd use #80FFFFFF.
100% — FF
95% — F2
90% — E6
85% — D9
80% — CC
75% — BF
70% — B3
65% — A6
60% — 99
55% — 8C
50% — 80
45% — 73
40% — 66
35%...
Convert INT to VARCHAR SQL
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Use the convert function.
SELECT CONVERT(varchar(10), field_name) FROM table_name
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What is sharding and why is it important?
... Horizontal partitioning is a design principle whereby rows of a database table are held separately, rather than splitting by columns (as for normalization). Each partition forms part of a shard, which may in turn be located on a separate database server or physical location. The advantage is the n...
SQLAlchemy IN clause
...Without the ORM, it would be
session.execute(
select(
[MyUserTable.c.id, MyUserTable.c.name],
MyUserTable.c.id.in_((123, 456))
)
).fetchall()
select() takes two parameters, the first one is a list of fields to retrieve, the second one is the where condition. You can acce...
Use email address as primary key?
...ies with multiple joins.
If you store information about users in multiple tables, the foreign keys to the users table will be the e-mail address. That means that you store the e-mail address multiple times.
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Improve INSERT-per-second performance of SQLite
...f possible, which will replace the implied unique row number column in the table.
If you are using multiple threads, you can try using the shared page cache, which will allow loaded pages to be shared between threads, which can avoid expensive I/O calls.
Don't use !feof(file)!
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