I have a table with multiple columns and wanted to find the maximum value in the entire table (across all columns), let me know if it is possible? if yes how
All columns are in integer data type
You can use MAX and GREATEST to achieve this.
Data Set:
CREATE TABLE test
(
col1 INTEGER,
col2 INTEGER,
col3 INTEGER
);
INSERT INTO test VALUES
(1,100,2 ),(2,300,3 ),(3,350, 400 );
You can achieve it using below.
SELECT Greatest(Max(col1), Max(col2), Max(col3)) as Max_Value
FROM test;
DB Fiddle: Try it here
In Postgres and Oracle (and I believe in MySQL as well) you can use:
select max(greatest(col_1, col_2, col_3, col_4))
from the_table;
Supose that you have these columns:
ID (PK)
Column 1 (int)
Column 2 (int)
Column 3 (int)
You can use a SELECT with a UNION clause inside it, something like this:
SELECT ID, MAX(FindNumber) AS FoundedNumber
FROM
(
SELECT ID, Column1 AS FindNumber
FROM YourTable
UNION
SELECT ID, Column2 AS FindNumber
FROM YourTable
UNION
SELECT ID, Column3 AS FindNumber
FROM YourTable
) subselect
GROUP BY ID
This solution is for Microsoft SQL Server.
I've got a query like this
select column, count(*)
from mytable
where column in ('XXX','YYY','ZZZ',....)
group by column;
But I want also to get a row for values the aren't in the table.
Let's suppose that 'ZZZ' doesn't exist in mytable, I'd like to get:
COLUMN COUNT(*)
XXX 3
YYY 2
ZZZ 0 (or NULL)
Oracle version 10g
Thanks in advance
Mark
In general, you would need to have a second table which contains all the possible column values whose counts you want to appear in the output. For demo purposes only, we can use a CTE for that:
WITH vals AS (
SELECT 'XXX' AS val UNION ALL
SELECT 'YYY' UNION ALL
SELECT 'ZZZ'
)
SELECT t1.val, COUNT(t2.col) AS cnt
FROM vals t1
LEFT JOIN mytable t2
ON t2.col = t1.val
GROUP BY
t1.val;
Does Big Query support operations like "REPLACE INSERT" or something related to that?
If I run a query like this twice:
INSERT INTO table(column1) VALUES(1)
It'll create a duplicated row, is it possible to insert a row only if a column with the same value does not exist?
Thanks!
Below should make it
#standardSQL
INSERT INTO yourTable(column1)
SELECT value FROM (SELECT 1 AS value)
LEFT JOIN yourTable
ON column1 = value
WHERE column1 IS NULL
Does this work for you?
INSERT INTO table(column1)
WITH s AS (SELECT 1 src)
SELECT src FROM s WHERE NOT EXISTS (
SELECT * FROM table t WHERE t.column1 = s.src
)
COUNT(DATECREATED)
88708
26625
17092
how to create a select query for viewing this three values in single column as different column names like
COUNT(DATECREATED) COUNT(DATECREATED) COUNT(DATECREATED)
88708 26625 17092
88708
88708
If you just want 1 row with 3 rows as columns, then use this. Here col is the alias for your count statement.
with tbl as
(select rownum as rno,col from
(your existing query) t
)
select (select col from tbl where rno=1) col1 ,
(select col from tbl where rno=2) col2,
(select col from tbl where rno=3 ) col3
from dual
If there are more rows and you want to use them as column, then read about Dynamic pivot in Oracle and you shall get your answer.
Finally i did like this.. Thanks all for quick reply
select sum(colname) as aliasname, sum(colname) as aliasname, sum(colname) as aliasname from
(select count(colname) as colname,0 as colname,0 as colname from cof
union all
select 0,count(colname),0 from cof where colname is not null
union all
select 0,0,count(colname) from cof where colname is not null);
We have a table which is of the form:
ID,Value1,Value2,Value3
1,2,3,4
We need to transform this into.
ID,Name,Value
1,'Value1',2
1,'Value2',3
1,'Value3',4
Is there a clever way of doing this in one SELECT statement (i.e without UNIONs)? The column names Value1,Value2 and Value3 are fixed and constant.
The database is oracle 9i.
Give a union a shot.
select ID, 'Value1' as Name, Value1 as Value from table_name union all
select ID, 'Value2', Value2 as Value from table_name union all
select ID, 'Value3', Value3 as Value from table_name
order by ID, Name
using union all means that the server won't perform a distinct (which is implicit in union operations). It shouldn't make any difference with the data (since your ID's should HOPEFULLY be different), but it might speed it up a bit.
This works on Oracle 10g:
select id, 'Value' || n as name,
case n when 1 then value1 when 2 then value2 when 3 then value3 end as value
from (select rownum n
from (select 1 from dual connect by level <= 3)) ofs, t
I think Oracle 9i had recursive queries? Anyway, I'm pretty sure it has CASE support, so even if it doesn't have recursive queries, you can just do "(select 1 from dual union all select 2 from dual union all select 3 from dual) ofs" instead. Abusing recursive queries is a bit more general- for Oracle. (Using unions to generate rows is portable to other DBs, though)
You can do it like this, but it's not pretty:
SELECT id,'Value 1' AS name,value1 AS value FROM mytable
UNION
SELECT id,'Value 2' AS name,value2 AS value FROM mytable
UNION
SELECT id,'Value 3' AS name,value3 AS value FROM mytable
Unioning three select statements should do the trick:
SELECT ID, 'Value1', Value1 AS Value
FROM TABLE
UNION
SELECT ID, 'Value2', Value2 AS Value
FROM TABLE
UNION
SELECT ID, 'Value3', Value3 AS Value
FROM TABLE
If you're using SQL Server 2005+ then you can use UNPIVOT
CREATE TABLE #tmp ( ID int, Value1 int, Value2 int, Value3 int)
INSERT INTO #tmp (ID, Value1, Value2, Value3) VALUES (1, 2, 3, 4)
SELECT
*
FROM
#tmp
SELECT
*
FROM
#tmp
UNPIVOT
(
[Value] FOR [Name] IN (Value1, Value2, Value3)
) uPIVOT
DROP TABLE #tmp
A UNION ALL, as others have suggested, is probably your best bet in SQL. You might also want to consider handling this in the front end depending on what your specific requirements are.
CTE syntax may be different for Oracle (I ran it in Teradata), but I only used CTE to provide test data, those 1 2 3 and 4. You can use temp table instead. The actual select statement is plain vanilla SQL and it will on any relational database.
For Sql Server, consider UNPIVOT as an alternative to UNION:
SELECT id, value, colname
FROM #temp t
UNPIVOT (Value FOR ColName IN (value1,value2,value3)) as X
This will return the column name as well. I'm unsure what the X is used for, but you can't leave it out.
Try this:
CTE creates a temp table with 4 values. You can run this as is in any database.
with TEST_CTE (ID) as
(select * from (select '1' as a) as aa union all
select * from (select '2' as b) as bb union all
select * from (select '3' as c) as cc union all
select * from (select '4' as d) as dd )
select a.ID, 'Value'|| a.ID, b.ID
from TEST_CTE a, TEST_CTE b
where b.ID = (select min(c.ID) from TEST_CTE c where c.ID > a.ID)
Here is the result set:
1 Value1 2
2 Value2 3
3 Value3 4
Enjoy!
Some afterthoughts.
^^^ CTE syntax may be different in Oracle. I could only run it in Teradata. You can substitute it with temp table or fix the syntax to make it Oracle compatible. The select statement is plain vanilla SQL that will work on any database.
^^^ Another thing to note. If ID field is numeric, you might need to cast it into CHAR in order to concatenate it with "Value".