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Favourite performance tuning tricks [closed]
...e following...
99% of problems I have seen are caused by putting too many tables in a join. The fix for this is to do half the join (with some of the tables) and cache the results in a temporary table. Then do the rest of the query joining on that temporary table.
Query Optimisation Checklist
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Troubleshooting “Illegal mix of collations” error in mysql
...the query. Here is an example that uses the COLLATE clause:
SELECT * FROM table ORDER BY key COLLATE latin1_general_ci;
Another option is to use the BINARY operator:
BINARY str is the shorthand for CAST(str AS BINARY).
Your solution might look something like this:
SELECT * FROM table WHERE...
Multiple columns index when using the declarative ORM extension of sqlalchemy
...just Column objects, index=True flag works normally:
class A(Base):
__tablename__ = 'table_A'
id = Column(Integer, primary_key=True)
a = Column(String(32), index=True)
b = Column(String(32), index=True)
if you'd like a composite index, again Table is present here as usual you just...
Angular.js ng-repeat across multiple tr's
...test through an html validator allowed multiple tbody elements in the same table.
Update: As of at least Angular 1.2 there is an ng-repeat-start and ng-repeat-end to allow repeating a series of elements. See the documentation for more information and thanks to @Onite for the comment!
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jquery UI Sortable with table and tr width
I am using jQuery UI sortable to make my table grid sortable. The code seems to work fine but because I am not adding width to td s, when I drag the tr it shrinks the content.
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How can foreign key constraints be temporarily disabled using T-SQL?
... database just run this code:
-- disable all constraints
EXEC sp_MSforeachtable "ALTER TABLE ? NOCHECK CONSTRAINT all"
To switch them back on, run: (the print is optional of course and it is just listing the tables)
-- enable all constraints
exec sp_MSforeachtable @command1="print '?'", @command...
Inserting multiple rows in mysql
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it's also possible to use INSERT INTO Table SELECT 1, '14/05/2012', 3 UNION SELECT 2, '05/14/2012', 3. of course, this will only be better of the inserted values are coming from different tables.
– Zohar Peled
Jun 1 '15 at 9...
How do I create a foreign key in SQL Server?
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create table question_bank
(
question_id uniqueidentifier primary key,
question_exam_id uniqueidentifier not null,
question_text varchar(1024) not null,
question_point_value decimal,
constraint fk_questionbank_ex...
Alter a MySQL column to be AUTO_INCREMENT
I’m trying to modify a table to make its primary key column AUTO_INCREMENT after the fact. I have tried the following SQL, but got a syntax error notification.
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Rails migration for change column
We have script/generate migration add_fieldname_to_tablename fieldname:datatype syntax for adding new columns to a model.
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