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SQLiteDatabase.query method
...
tableColumns
null for all columns as in SELECT * FROM ...
new String[] { "column1", "column2", ... } for specific columns as in SELECT column1, column2 FROM ... - you can also put complex expressions here:
new String[] { "(SELECT max(column1) FROM table1) AS max" }...
How do I perform an IF…THEN in an SQL SELECT?
How do I perform an IF...THEN in an SQL SELECT statement?
30 Answers
30
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How to convert DateTime to VarChar
...yDateTime DATETIME
SET @myDateTime = '2008-05-03'
--
-- Convert string
--
SELECT LEFT(CONVERT(VARCHAR, @myDateTime, 120), 10)
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SQL - using alias in Group By
... following order:
FROM clause
WHERE clause
GROUP BY clause
HAVING clause
SELECT clause
ORDER BY clause
For most relational database systems, this order explains which names (columns or aliases) are valid because they must have been introduced in a previous step.
So in Oracle and SQL Server, you...
How to make an Android Spinner with initial text “Select One”?
I want to use a Spinner that initially (when the user has not made a selection yet) displays the text "Select One". When the user clicks the spinner, the list of items is displayed and the user selects one of the options. After the user has made a selection, the selected item is displayed in the Spi...
Finding duplicate values in a SQL table
...
SELECT
name, email, COUNT(*)
FROM
users
GROUP BY
name, email
HAVING
COUNT(*) > 1
Simply group on both of the columns.
Note: the older ANSI standard is to have all non-aggregated columns in the GROUP BY ...
Get top 1 row of each group
...
;WITH cte AS
(
SELECT *,
ROW_NUMBER() OVER (PARTITION BY DocumentID ORDER BY DateCreated DESC) AS rn
FROM DocumentStatusLogs
)
SELECT *
FROM cte
WHERE rn = 1
If you expect 2 entries per day, then this will arbitrarily pick one...
How to create a SQL Server function to “join” multiple rows from a subquery into a single delimited
...
If you're using SQL Server 2005, you could use the FOR XML PATH command.
SELECT [VehicleID]
, [Name]
, (STUFF((SELECT CAST(', ' + [City] AS VARCHAR(MAX))
FROM [Location]
WHERE (VehicleID = Vehicle.VehicleID)
FOR XML PATH ('')), 1, 2, '')) AS Locations
FROM [...
Detect if value is number in MySQL
...
This should work in most cases.
SELECT * FROM myTable WHERE concat('',col1 * 1) = col1
It doesn't work for non-standard numbers like
1e4
1.2e5
123. (trailing decimal)
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Function to Calculate Median in SQL Server
... in all cases. It also requires SQL 2012 or later.
DECLARE @c BIGINT = (SELECT COUNT(*) FROM dbo.EvenRows);
SELECT AVG(1.0 * val)
FROM (
SELECT val FROM dbo.EvenRows
ORDER BY val
OFFSET (@c - 1) / 2 ROWS
FETCH NEXT 1 + (1 - @c % 2) ROWS ONLY
) AS x;
Of course, just because o...