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MySQL: Transactions vs Locking Tables
I'm a bit confused with transactions vs locking tables to ensure database integrity and make sure a SELECT and UPDATE remain in sync and no other connection interferes with it. I need to:
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On Duplicate Key Update same as insert
...ould be no need to re-update it.
Alternatively, you can use:
INSERT INTO table (id,a,b,c,d,e,f,g)
VALUES (1,2,3,4,5,6,7,8)
ON DUPLICATE KEY
UPDATE a=a, b=b, c=c, d=d, e=e, f=f, g=g;
To get the id from LAST_INSERT_ID; you need to specify the backend app you're using for the same.
For LuaSQL...
Can we use join for two different database tables?
Can we use the join operation for two tables from different databases? If yes, how do I do it?
2 Answers
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MySQL - SELECT WHERE field IN (subquery) - Extremely slow why?
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Rewrite the query into this
SELECT st1.*, st2.relevant_field FROM sometable st1
INNER JOIN sometable st2 ON (st1.relevant_field = st2.relevant_field)
GROUP BY st1.id /* list a unique sometable field here*/
HAVING COUNT(*) > 1
I think st2.relevant_field must be in the select, because other...
Retrieving the last record in each group - MySQL
There is a table messages that contains data as shown below:
27 Answers
27
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Copy values from one column to another in the same table
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Short answer for the code in question is:
UPDATE `table` SET test=number
Here table is the table name and it's surrounded by grave accent (aka back-ticks `) as this is MySQL convention to escape keywords (and TABLE is a keyword in that case).
BEWARE, that this is pretty d...
LINQ to SQL: Multiple joins ON multiple Columns. Is this possible?
...olumns in Linq to SQL is a little different.
var query =
from t1 in myTABLE1List // List<TABLE_1>
join t2 in myTABLE1List
on new { t1.ColumnA, t1.ColumnB } equals new { t2.ColumnA, t2.ColumnB }
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You have to take advantage of anonymous types and compose a type for the mu...
HTML input textbox with a width of 100% overflows table cells
Does anyone know why the input elements with a width of 100% go over the table's cells border.
14 Answers
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Fit cell width to content
...question, but I'll take a stab at it. JSfiddle of the example.
HTML:
<table style="width: 100%;">
<tr>
<td class="block">this should stretch</td>
<td class="block">this should stretch</td>
<td class="block">this should be the content width</...
How to add “on delete cascade” constraints?
...ible to add ON DELETE CASCADES to the both foreign keys in the following table without dropping the latter?
3 Answers
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