How to get row number in select query - php

i try this query to get row number in selected rows, but the output comes like 23,56,78,.... i need to get 1,2,3 to every selected row. please help me
SET #row=0;
SELECT `table1`.`col1`,`table1`.`col2`,#row:=#row+1
FROM `table1`
LEFT OUTER JOIN `table2` ON `table1`.`col1` = `table2`.`col5`
WHERE `table2`.`col5` IS NOT NULL
GROUP BY `col1` ORDER BY `table1`.`col7` DESC LIMIT 0,10


Move the query with the ORDER BY clause into a subquery.
SET #row = 0;
SELECT col1, col2, #row := #row+1
FROM (SELECT table1.col1, table1.col2
FROM table1
LEFT JOIN table2 ON table1.col1 = table2.col5
WHERE table2.col5 IS NOT NULL
GROUP BY col1
ORDER BY table1.col7 DESC
LIMIT 0, 10) AS subquery


You can try using an inline view. Use a query that gets the rows you want to return, and then wrap that in parens, and reference that query in the FROM clause of an outer query.
Something like this:
SELECT v.`col1`
, v.`col2`
, #row := #row + 1 AS `rn`
FROM ( SELECT `table1`.`col1`
, `table1`.`col2`
FROM `table1`
...
ORDER BY ...
LIMIT 10
) v

Related

MySQL return union select results separated in groups

I would like to know if is possible to return the results from UNION grouped by their alias.
For instance:
(SELECT * FROM table1) AS first
UNION
(SELECT * FROM table2) AS second
so that the result is:
first = contains all table1 rows
second = contains all table2 rows
Practically i want an associative array like this:
[]=>[
'first'=>[table1 results],
'second'=>[table2 results]
]
I tried it but doesn't work. Maybe i'm doing it bad.
Can this be done with a single query or i've to do 2 separated queries.
Thanks.

You cannot do this with union because it removes duplicates. You can with union all.
One way is:
SELECT t.*, 0 as which FROM table1 t
UNION ALL
SELECT t.*, 1 FROM table2 t
ORDER BY which;
If you don't want to see which in the output, use a subquery:
select . . .
from (select t.*, 0 as which from table1 t union all
select t.*, 1 as which from table1 t
) t
order by which;

Get multiple row counts [duplicate]

I am wondering how to write this query.
I know this actual syntax is bogus, but it will help you understand what I want.
I need it in this format, because it is part of a much bigger query.
SELECT distributor_id,
COUNT(*) AS TOTAL,
COUNT(*) WHERE level = 'exec',
COUNT(*) WHERE level = 'personal'
I need this all returned in one query.
Also, it need to be in one row, so the following won't work:
'SELECT distributor_id, COUNT(*)
GROUP BY distributor_id'

You can use a CASE statement with an aggregate function. This is basically the same thing as a PIVOT function in some RDBMS:
SELECT distributor_id,
count(*) AS total,
sum(case when level = 'exec' then 1 else 0 end) AS ExecCount,
sum(case when level = 'personal' then 1 else 0 end) AS PersonalCount
FROM yourtable
GROUP BY distributor_id

One way which works for sure
SELECT a.distributor_id,
(SELECT COUNT(*) FROM myTable WHERE level='personal' and distributor_id = a.distributor_id) as PersonalCount,
(SELECT COUNT(*) FROM myTable WHERE level='exec' and distributor_id = a.distributor_id) as ExecCount,
(SELECT COUNT(*) FROM myTable WHERE distributor_id = a.distributor_id) as TotalCount
FROM (SELECT DISTINCT distributor_id FROM myTable) a ;
EDIT:
See #KevinBalmforth's break down of performance for why you likely don't want to use this method and instead should opt for #Taryn♦'s answer. I'm leaving this so people can understand their options.

SELECT
distributor_id,
COUNT(*) AS TOTAL,
COUNT(IF(level='exec',1,null)),
COUNT(IF(level='personal',1,null))
FROM sometable;
COUNT only counts non null values and the DECODE will return non null value 1 only if your condition is satisfied.

Building on other posted answers.
Both of these will produce the right values:
select distributor_id,
count(*) total,
sum(case when level = 'exec' then 1 else 0 end) ExecCount,
sum(case when level = 'personal' then 1 else 0 end) PersonalCount
from yourtable
group by distributor_id
SELECT a.distributor_id,
(SELECT COUNT(*) FROM myTable WHERE level='personal' and distributor_id = a.distributor_id) as PersonalCount,
(SELECT COUNT(*) FROM myTable WHERE level='exec' and distributor_id = a.distributor_id) as ExecCount,
(SELECT COUNT(*) FROM myTable WHERE distributor_id = a.distributor_id) as TotalCount
FROM myTable a ;
However, the performance is quite different, which will obviously be more relevant as the quantity of data grows.
I found that, assuming no indexes were defined on the table, the query using the SUMs would do a single table scan, while the query with the COUNTs would do multiple table scans.
As an example, run the following script:
IF OBJECT_ID (N't1', N'U') IS NOT NULL
drop table t1
create table t1 (f1 int)
insert into t1 values (1)
insert into t1 values (1)
insert into t1 values (2)
insert into t1 values (2)
insert into t1 values (2)
insert into t1 values (3)
insert into t1 values (3)
insert into t1 values (3)
insert into t1 values (3)
insert into t1 values (4)
insert into t1 values (4)
insert into t1 values (4)
insert into t1 values (4)
insert into t1 values (4)
SELECT SUM(CASE WHEN f1 = 1 THEN 1 else 0 end),
SUM(CASE WHEN f1 = 2 THEN 1 else 0 end),
SUM(CASE WHEN f1 = 3 THEN 1 else 0 end),
SUM(CASE WHEN f1 = 4 THEN 1 else 0 end)
from t1
SELECT
(select COUNT(*) from t1 where f1 = 1),
(select COUNT(*) from t1 where f1 = 2),
(select COUNT(*) from t1 where f1 = 3),
(select COUNT(*) from t1 where f1 = 4)
Highlight the 2 SELECT statements and click on the Display Estimated Execution Plan icon. You will see that the first statement will do one table scan and the second will do 4. Obviously one table scan is better than 4.
Adding a clustered index is also interesting. E.g.
Create clustered index t1f1 on t1(f1);
Update Statistics t1;
The first SELECT above will do a single Clustered Index Scan. The second SELECT will do 4 Clustered Index Seeks, but they are still more expensive than a single Clustered Index Scan. I tried the same thing on a table with 8 million rows and the second SELECT was still a lot more expensive.

For MySQL, this can be shortened to:
SELECT distributor_id,
COUNT(*) total,
SUM(level = 'exec') ExecCount,
SUM(level = 'personal') PersonalCount
FROM yourtable
GROUP BY distributor_id

Well, if you must have it all in one query, you could do a union:
SELECT distributor_id, COUNT() FROM ... UNION
SELECT COUNT() AS EXEC_COUNT FROM ... WHERE level = 'exec' UNION
SELECT COUNT(*) AS PERSONAL_COUNT FROM ... WHERE level = 'personal';
Or, if you can do after processing:
SELECT distributor_id, COUNT(*) FROM ... GROUP BY level;
You will get the count for each level and need to sum them all up to get the total.

I do something like this where I just give each table a string name to identify it in column A, and a count for column. Then I union them all so they stack. The result is pretty in my opinion - not sure how efficient it is compared to other options but it got me what I needed.
select 'table1', count (*) from table1
union select 'table2', count (*) from table2
union select 'table3', count (*) from table3
union select 'table4', count (*) from table4
union select 'table5', count (*) from table5
union select 'table6', count (*) from table6
union select 'table7', count (*) from table7;
Result:
-------------------
| String | Count |
-------------------
| table1 | 123 |
| table2 | 234 |
| table3 | 345 |
| table4 | 456 |
| table5 | 567 |
-------------------

Based on Taryn's response with an added nuance using OVER():
SELECT distributor_id,
COUNT(*) total,
SUM(case when level = 'exec' then 1 else 0 end) OVER() ExecCount,
SUM(case when level = 'personal' then 1 else 0 end) OVER () PersonalCount
FROM yourtable
GROUP BY distributor_id
Using OVER() with nothing in the () will give you the total count for the whole dataset.

I think this can also works for you select count(*) as anc,(select count(*) from Patient where sex='F')as patientF,(select count(*) from Patient where sex='M') as patientM from anc
and also you can select and count related tables like this select count(*) as anc,(select count(*) from Patient where Patient.Id=anc.PatientId)as patientF,(select count(*) from Patient where sex='M') as patientM from anc

In Oracle you'll do something like
SELECT
(SELECT COUNT(*) FROM schema.table1),
(SELECT COUNT(*) FROM schema.table2),
...
(SELECT COUNT(*) FROM schema.tableN)
FROM DUAL;

If your flavor of SQL supports it, you can use COUNT_IF() to count based on a condition.
SELECT
distributor_id,
COUNT(*) AS total_count,
COUNT_IF(level = 'exec') AS exec_count,
COUNT_IF(level = 'personal') AS personal_count
FROM table_name
GROUP BY distributor_id

The recently added PIVOT functionality can do exactly what you need:
SELECT *
FROM ( SELECT level from your_table )
PIVOT ( count(*) for level in ('exec', 'personal') )

To get count of a row with particular condition

I want to get count of a row it exists in table.
+---+----+
|id |name|
+---+----+
|100|a |
+---+----+
|201|b |
+---+----+
|302|c |
+---+----+
|403|d |
+---+----+
|504|e |
+---+----+
In the above table i want to get output as 4(i.e) the count of that row exists. I have 'd' value and have to write a query to get the output as 4 where name = d
I think code will be something like the below,
select count(*) ......

If i'm correctly understand you this query is what you want:
set #row_number = 0;
select #row_number := #row_number + 1 as row_number,name FROM table_name;

SELECT ROW_NUMBER() OVER(ORDER BY id) FROM yourtable WHERE name='d'
MySQL version
SET #rank=0;
SELECT #rank := #rank+1 AS rank
FROM yourtable WHERE name='d'
ORDER BY id asc

#vinoth I think #Pragmatist Answer would work for you. Just add this clause to his query :
set #row_number = 0;
select #row_number := #row_number + 1 as row_number,name FROM table_name Where name='b';

Try the below. MS SQL is a tested query, i just converted into mysql. Hope you can modify as per your requirement.
SET #rank=0;
SELECT * FROM Table1 T1
INNER JOIN(
SELECT #rank := #rank+1 AS rank, ID
FROM Table1
ORDER BY id asc) temp ON temp.ID = T1.ID
WHERE T1.name = 'd'
MS SQL Query will be
SELECT * FROM Table1 T1
INNER JOIN(SELECT id, ROW_NUMBER() OVER (Order by id) AS RowNumber from Table1) temp ON temp.ID = T1.ID
WHERE T1.name = 'd'

To get the Row Number
SELECT ROW_NUMBER() OVER(ORDER BY id) from table WHERE name='d'
To get the row count with your condition use below query
select count(*) as count from table where name = 'b'

Combining two mysql queries

I have two sql queries...
set #count:=0;
select #count:=#count+1 as SNO, col1, col2 FROM table;
I want to combine above queries into a single query. Any Help?

You can simply do this,
select #count:=#count+1 as SNO, col1, col2
FROM table, (SELECT #count:=0) r ;
Just like adding RowNumber for each row
select #rownum:=#rownum+1 ‘rank’,
p.*
from player p, (SELECT #rownum:=0) r
order by score
desc limit 10;
Adding RowNumber in MySQL

As per my understanding,you are looking for Row_Number function in this case. If this is correct, please have a look here
e.g.
Select #count := #count + 1 As SNO, col1, col2
From table ,(SELECT #count:=0) foo
may help
Also you can refer ROW_NUMBER, Partition, and Over in MySQL for more understanding on the same

Combining two queries..
SELECT t1.field1, t1.field2, t2.field1
FROM (query1) as t1, (query2) as t2
WHERE t1.field1= t2.field1
Hope this will works ...

select #count:=#count+1 as SNO, col1, col2 FROM table, (SELECT #count:=0) t;

Limit the amount of results from mySQL conditionally?

Here is my query:
SELECT * FROM Photos WHERE Event_ID IN ($eventidstring)
I know I can limit the total amount of results from this query using LIMIT 5
I need the Limit the amount of results Per value in $eventidstring.
So if $eventidstring = 23,41,23*
*And there are 10 results WHERE Event_ID = 23, I want to limit this amount to 5. The same for all the other values in $eventidstring.

You may have some joy doing something similar to Oracle's RANK by PARITION in MySQL.
Sadly this feature is not available in MySQL though you can work around it using this method
Dump that in an inline view and then select those rows with rank <= 5;
Hence:
SELECT t.* FROM (
SELECT (
CASE Event_id
WHEN #curEventId
THEN #curRow := #curRow + 1
ELSE #curRow := 1 AND #curEventId := Event_Id END
) AS rank,
p.*
FROM Photos p INNER JOIN (SELECT #curRow := 0, #curEventId := '') r
ORDER BY p.Event_Id DESC
) t
WHERE t.rank <= 5 ORDER BY t.Event_Id asc;
Consider how you are going to 'choose' the top five by Event_Id too. You can always add in more after the ORDER BY p.Event_Id DESC to decide this.

I take it you're writing that query somewhere inside your PHP, so you need to split the $eventidstring into it's component values, form a SELECT for each and UNION all after the first one.
You sould do this with a loop of some sort, and concatenate the query strings in the loop...

If I understand correctly and you want to get five of each, you can use this:
(SELECT * FROM Photos WHERE Event_ID = 23 LIMIT 5)
UNION
(SELECT * FROM Photos WHERE Event_ID = 41 LIMIT 5)
UNION
(SELECT * FROM Photos WHERE Event_ID = ... LIMIT 5)
...

Maybe with a SELECT UNION but you need a new select for each value:
SELECT * FROM Photos WHERE Event_ID = 23 LIMIT 5
UNION SELECT * FROM Photos WHERE Event_ID = 41 LIMIT 5
UNION SELECT ...

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