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MySQL select where column is not empty
In MySQL, can I select columns only where something exists?
13 Answers
13
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When to use a View instead of a Table?
...
Oh there are many differences you will need to consider
Views for selection:
Views provide abstraction over tables. You can add/remove fields easily in a view without modifying your underlying schema
Views can model complex joins easily.
Views can hide database-specific stuff from you. E....
Add primary key to existing table
...PMID)
edit:
you can find the constraint name by using the query below:
select OBJECT_NAME(OBJECT_ID) AS NameofConstraint
FROM sys.objects
where OBJECT_NAME(parent_object_id)='Persion'
and type_desc LIKE '%CONSTRAINT'
sh...
Computed / calculated / virtual / derived columns in PostgreSQL
...y as column?
The expression (looking like a column) is not included in a SELECT * FROM tbl, though. You always have to list it explicitly.
Can also be supported with a matching expression index - provided the function is IMMUTABLE. Like:
CREATE FUNCTION col(tbl) ... AS ... -- your computed expr...
A circular reference was detected while serializing an object of type 'SubSonic.Schema .DatabaseColu
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I think maybe selecting the ones I want may work I think the circular reference is because in Event I have IQueryable<Category> which in turn will have a IQueryable<Event>
– Jon
Jul 20 '09...
XML Schema minOccurs / maxOccurs default values
...ml>
<body>
<xsl:for-each select="country">
<xsl:value-of select="countryName"/><br/>
<xsl:value-of select="capital"/><br/>
<xsl:value-of select="nation...
Selecting the first “n” items with jQuery
With Jquery, I need to select just the first "n" items from the page, for example the first 20 links instead of selecting all of them with the usual
...
Get the generated SQL statement from a SqlCommand object?
... }
sql.AppendLine(";");
sql.AppendLine("select 'Return Value' = convert(varchar, @return_value);");
foreach (SqlParameter sp in sc.Parameters)
{
if ((sp.Direction == ParameterDirection.InputOutput) || (sp.Directi...
How to build a query string for a URL in C#?
...om key in nvc.AllKeys
from value in nvc.GetValues(key)
select string.Format(
"{0}={1}",
HttpUtility.UrlEncode(key),
HttpUtility.UrlEncode(value))
).ToArray();
return "?" + string.Join("&", array);
}
I imagine there...
MySQL query String contains
...
Quite simple actually:
mysql_query("
SELECT *
FROM `table`
WHERE `column` LIKE '%{$needle}%'
");
The % is a wildcard for any characters set (none, one or many). Do note that this can get slow on very large datasets so if your database grows you'll need to use ...