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How do I make a composite key with SQL Server Management Studio?
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Open the design table tab
Highlight your two INT fields (Ctrl/Shift+click on the grey blocks in the very first column)
Right click -> Set primary key
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What is the simplest SQL Query to find the second largest value?
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SELECT MAX( col )
FROM table
WHERE col < ( SELECT MAX( col )
FROM table )
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SQL Server - SELECT FROM stored procedure
...ure can return multiple result sets, each with its own schema. It's not suitable for using in a SELECT statement.
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Cannot resolve the collation conflict between “SQL_Latin1_General_CP1_CI_AS” and “Latin1_General_CI_
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You have a mismatch of two different collations in your table. You can check what collations each column in your table(s) has by using this query:
SELECT
col.name, col.collation_name
FROM
sys.columns col
WHERE
object_id = OBJECT_ID('YourTableName')
Collations are n...
COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better? [duplicate]
...OUNT(*), and stick with it consistently, and if your database allows COUNT(tableHere) or COUNT(tableHere.*), use that.
In short, don't use COUNT(1) for anything. It's a one-trick pony, which rarely does what you want, and in those rare cases is equivalent to count(*)
Use count(*) for counting
U...
How to 'insert if not exists' in MySQL?
I started by googling, and found this article which talks about mutex tables.
10 Answers
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Simple Pivot Table to Count Unique Values
This seems like a simple Pivot Table to learn with. I would like to do a count of unique values for a particular value I'm grouping on.
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Add default value of datetime field in SQL Server to a timestamp
I've got a table that collects forms submitted from our website, but for some reason, when they created the table, they didn't put a timestamp in the table. I want it to enter the exact date and time that the record was entered.
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WHERE vs HAVING
... answers on this question didn't hit upon the key point.
Assume we have a table:
CREATE TABLE `table` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`value` int(10) unsigned NOT NULL,
PRIMARY KEY (`id`),
KEY `value` (`value`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8
And have 10 rows with both ...
How to select rows that have current day's timestamp?
I am trying to select only today's records from a database table.
9 Answers
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