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Implement paging (skip / take) functionality with this query
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In SQL Server 2012 it is very very easy
SELECT col1, col2, ...
FROM ...
WHERE ...
ORDER BY -- this is a MUST there must be ORDER BY statement
-- the paging comes here
OFFSET 10 ROWS -- skip 10 rows
FETCH NEXT 10 ROWS ONLY; -- take 10 rows
If we want...
Using union and order by clause in mysql
...criteria from a table based on distance for a search on my site.
The first select query returns data related to the exact place search .
The 2nd select query returns data related to distance within 5 kms from the place searched.
The 3rd select query returns data related to distance within 5-15 kms f...
Nested select statement in SQL Server
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You need to alias the subquery.
SELECT name FROM (SELECT name FROM agentinformation) a
or to be more explicit
SELECT a.name FROM (SELECT name FROM agentinformation) a
share
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How to use GROUP_CONCAT in a CONCAT in MySQL
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select id, group_concat(`Name` separator ',') as `ColumnName`
from
(
select
id,
concat(`Name`, ':', group_concat(`Value` separator ',')) as `Name`
from mytbl
group by
id,
`Name`
) tbl
group by id;
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Is there a better way to dynamically build an SQL WHERE clause than by using 1=1 at its beginning?
... {2}", clause, appender, condition);
}
Use it like this
string query = "SELECT * FROM Table1 {0}";
string whereClause = string.Empty;
if (condition 1)
whereClause = AddCondition(whereClause, "AND", "Col=1");
if (condition 2)
whereClause = AddCondition(whereClause, "AND", "Col2=2");
str...
Selecting a row of pandas series/dataframe by integer index
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The primary purpose of the DataFrame indexing operator, [] is to select columns.
When the indexing operator is passed a string or integer, it attempts to find a column with that particular name and return it as a Series.
So, in the question above: df[2] searches for a column name matchin...
How to create an object for a Django model with a many to many field?
...dd(bar1)
foo.bars.add(bar2)
It generates a whopping total of 7 queries:
SELECT "app_bar"."id", "app_bar"."name" FROM "app_bar" WHERE "app_bar"."id" = 1
SELECT "app_bar"."id", "app_bar"."name" FROM "app_bar" WHERE "app_bar"."id" = 2
INSERT INTO "app_foo" ("name") VALUES ()
SELECT "app_foo_bars"."b...
How to select all records from one table that do not exist in another table?
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SELECT t1.name
FROM table1 t1
LEFT JOIN table2 t2 ON t2.name = t1.name
WHERE t2.name IS NULL
Q: What is happening here?
A: Conceptually, we select all rows from table1 and for each row we attempt to find a row in table2 wi...
How to drop columns by name in a data frame
..."z","u"))]
x y
1 1 2
2 2 3
3 3 4
4 4 5
5 5 6
Or, much simpler, use the select argument of the subset function : you can then use the - operator directly on a vector of column names, and you can even omit the quotes around the names !
R> subset(df, select=-c(z,u))
x y
1 1 2
2 2 3
3 3 4
4 4 ...
Check for changes to an SQL Server table?
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Take a look at the CHECKSUM command:
SELECT CHECKSUM_AGG(BINARY_CHECKSUM(*)) FROM sample_table WITH (NOLOCK);
That will return the same number each time it's run as long as the table contents haven't changed. See my post on this for more information:
CHECKSUM...