SQL term used to describe when a `SELECT` statement is used as part of a larger SQL statement. The larger statement may be DML and is always found within brackets or parenthesis.

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1answer
30 views

View vs TableValued Function vs SubQuery

I have a scenario where i need to join with 3 tables to get the value for one field for second field join with 4 tables for third field join with 3 tables all above joins are inner and if data ...
1
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4answers
39 views

where clause: if this value from col x make sure col y is this value

I feel like this is an easy one for you Experts! I haven't done any kind of Advanced SQL in years. Fundamental question: select * from myTable where ((if col1 = 'this', make sure col2 = ...
0
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1answer
19 views

Count(*) as rolecount, filter by rolecount = 1

How can i filter out the rows who only got rolecount = 1? WHERE rolecount = 1 gives an error. Can't really figure out how to do it. SELECT u.uid AS uid, u.name AS name, u.picture AS picture, ...
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2answers
18 views

Is my subquery inneficient. It is extremely slow

I have two tables. Member information and login entries. I am simply trying to display the member information table sorted by the last login access date. So i created this query, but it is extremely ...
0
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1answer
37 views

If a query contains two identical subqueries, will they both run?

Say I have a SELECT query that contains two identical subqueries, like the below: SELECT (SELECT SUM(Price) FROM Product p WHERE p.GroupID = g.GroupID) AS 'TotalCost', (SELECT SUM(Price) ...
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1answer
66 views

Selecting data from multiple rows and insert it into a column

My table is like this: temp1 name city phone_no pincode ----------------------------------- amit Delhi 12345 123 Rajiv Bombay 836536 432 How do I transform the last ...
0
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1answer
62 views

How to INNER JOIN and OUTER JOIN within the same table?

I am using PostgreSQL and I have the following tables: Product ID | Name | Price Receipts ID | Month | Quantity | Product_ID (FK) Sales ID | Month | Quantity | Product_ID (FK) I am trying to ...
7
votes
3answers
185 views

Optimize select on subquery with COALESCE(…)

I have a large view that I use from within an application. I think I've narrowed down my performance problem, but I'm unsure how to fix it. A simplified version of the view looks like this: SELECT ...
0
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1answer
44 views

How do I count and order by unique entries?

I have this: SELECT tblClient.[Printed Name], tblClient.[Address 1], tblClient.[Address 2], tblClient.City, tblClient.State, tblClient.Zip, tblClient.Phone, tblClient.[Email Address] FROM tblClient ...
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0answers
21 views

How to include a GROUP_CONCAT list to result from subquery

I am trying to construct a nested query over the following 3 tables users, cars and bookings. Table users Table cars Table bookings +---------+ +--------+------------+ ...
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votes
2answers
113 views

how to solve slow running sub query TSQL

I have a problem with a slow running query. I have analysed the query with the sql server profiler but I can't seem to find a good solution. I did find why it is running slow. If ask the full ...
0
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0answers
140 views

Multiple SELECT subqueries in an INSERT statement in a stored procedure

So I had the following (genericized), which works just fine for me (barring errors in making the example generic) : DELIMITER // CREATE PROCEDURE stored_proc(IN val1 INT, IN date1 DATETIME, IN date2 ...
0
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1answer
39 views

How to optimise very simple query with subquery that only needs to execute once

SELECT products_id, products_model, products_iban_no, products_allocation_number FROM products WHERE products_model IN (SELECT products_model FROM products GROUP BY products_model HAVING ...
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1answer
22 views

postgres: how to use subquery correctly?

I have the following query CREATE TABLE test_buffslip AS SELECT ST_INTERSECTS( (SELECT ST_Buffer(geom, 0.005) FROM segments where class = 7) ,geom) FROM segments; resulting in ...
0
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2answers
57 views

Problem in Nested Query

I have a query like this SELECT m.title FROM Movie AS M WHERE (SELECT MAX(r.stars) FROM rating AS r WHERE r.mID = M.mID); I want to show the MAX(r.stars) in my result set, what am I doing wrong?
0
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1answer
76 views

Very slow update with subquery (different tables)

I run this query to update "domains" table based on "log" table: UPDATE domains SET domains.mx_collected = 0 WHERE domains.domain IN (SELECT log.mail as domain_name FROM log WHERE `time` >= ...
2
votes
1answer
897 views

Writing a query to find all employee salaries that are higher than their managers

I have two tables with some dummy data. I need to find all employees that make more than their managers. I was led to believe the point of the exercise is to learn how to do subqueries. I can isolate ...
1
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1answer
137 views

Why does IN (subquery) perform bad when = (subquery) is blazing fast?

Have a look at these two queries: Simple: mysql> SELECT * FROM omgbatch JOIN omgoutput ON (idomgbatch=omgbatch) WHERE idomgoutput = (SELECT DISTINCT lastoutput FROM omgenvelope WHERE ...
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0answers
55 views

Latest of group in subquery is bottleneck, how to optimizing query?

See Original question I'm fetching the activity data for the latest activity for each company as part of a bigger query. I've been using the method provided by ypercube, and it works fine, but I find ...
1
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1answer
163 views

Select query for returning different data based on creation time

I have a view, which will Select data from table reports the select will filter the data based on multiple dates. reports table: id, key_id, position, created_at My select: pr.key_id, ...
0
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1answer
67 views

Take query results and insert into new table [closed]

So I have the following query: DECLARE @tbl TABLE(value int) *--The same function but with the number of the random numbers ;WITH Nbrs (n) AS ( SELECT 1 UNION ALL SELECT 1 + n FROM ...
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0answers
73 views

Unable to send WHERE parameters to subquery

I have the following problem (in PostgreSQL in combination with PostGIS): I have the following nice query who clusters multiple records. Although it uses PostGIS function, my problem is not PostGIS ...
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1answer
80 views

Aliases with correlated subqueries

I am looking at an example of correlated subquery with aliases from a PostgreSQL book: bpsimple=# SELECT * FROM orderinfo o, bpsimple=# (SELECT * FROM customer c WHERE town = 'Bingham') c bpsimple=# ...
2
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1answer
139 views

Find the second highest value from a subquery or derived table

I have a subquery which returns the following results. 'c003', '120000.00' 'c002', '90000.00' 'c001', '20000.00' 'c005', '8000.00' 'c004', '5000.00' I want to find the second highest value from ...
0
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2answers
498 views

How to find the same salaries and department names?

Write a query to display last name ,department number,and salary of any employee whose department number and salary both match the department number and salary of any employee using the following ...
0
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1answer
59 views

How do I solve this problem of a correlated subquery

We have an employee table with the following attributes : employee_id first_name last_name email phone_number hire_date job_id salary commission_pct manager_id department_id Display the manager ...
4
votes
1answer
49 views

Changes access method for non-correlated subquery

Oracle 11g R2 Unfortunately our application has per row security "features". We have a query that looks about like this: Bad, slow: SELECT someRow, someOtherRow FROM bigTableA a WHERE EXISTS ( ...
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2answers
117 views

optimization of expensive subquery

The following query gets the last report (where latitude and longitude and secs are <> 0) associated with the specified units: SELECT reports.* FROM reports INNER JOIN ...
2
votes
1answer
40 views

Update only the oldest entry in a table with foreign key criteria

I'm working on a forum website. What I am trying to do is updating the thread Title and Content (first post), which resides in different tables - "Threads" and "Posts". "Threads" "Posts" I'm ...
0
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0answers
35 views

subqueries with select

This below query works as expected: SELECT reports.* FROM reports INNER JOIN units ON units.id = reports.unit_id WHERE reports.unit_id IN (1111, 1112, 1113) ...
0
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1answer
61 views

Can this where in subquery be optimized?

Currently the query takes ~ 0.2 seconds. Is this the best it gets? Because it feels rather slow for the amount of data I have in my database. I've tried creating an inner join out of it but I can't ...
1
vote
2answers
70 views

How do I add an alias to the table

SELECT MAX(COUNT), A.id FROM ( SELECT supplier_id as id, COUNT(*) AS count FROM `library`.`lms_book_details` GROUP BY supplier_id ) GROUP BY A.id; While executing the query, MySQL gives ...
0
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2answers
109 views

MAX from Subquery [closed]

How do I find the maximum value of a particular column from the result of a SubQuery? For example, if the result of the subquery is: 10 20 30 How do I get maximum from this, in this case 30?
1
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1answer
188 views

Postgres, levenshtein distance and nested queries

I have a DB Table with 3,000,000 rows or more like that: |ID|T4|T16|T64|TL where ID =INTEGER (PK) and T4,T16,T64,TL are text fields. Each one is larger in length than the previous, i.e., LENGTH(T4) ...
0
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0answers
122 views

Alternatives for subquery

There are three tables: product_hits, products, and product_subcategory_map. I want to count the number of product_hits and for each product. There could be more than one subcategory in the ...
0
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2answers
76 views

Subquerying results in no row returned although records exist

I have two tables, namely Employees and Payments. Below is the contents of the two: The Employees table EmpID |EmpName ------ -------- 113 Harry The Payments table EmpID | Amount | Period ...
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0answers
170 views

MySQL Pre-Filter Subquery

Good Evening All, I'm trying to pre-filter a table such that the more complex MATCH ... AGAINST query doesn't need to process every row in the DB. I tried obtaining a list of identifiers (query 3) ...
1
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1answer
65 views

Counting number of visitors who did NOT log in

I'm trying to calculate the number of visitors to the homepage of my site who did NOT then log in to the member's section of the site, while also filtering bots and admin users. Bots and admins are ...
3
votes
1answer
517 views

Why does SQL Server run a subquery for each row of the table it's qualifying?

This query runs in ~21 seconds (execution plan): select a.month , count(*) from SubqueryTest a where a.year = (select max(b.year) from SubqueryTest b) group by a.month When the subquery ...
1
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1answer
978 views

MySQL Subquery returns more than one row

I have a table namely tbl_plays. It has the following columns and data id(PK)| gameid | drawid | etc ---------------------------------------------- 1 | 1509 | 73 | ...
11
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1answer
260 views

Why does subquery use parallelism and join doesn't?

Why does SQL server use parallelism when running this query which uses a subquery but it doesn't when using a join? The join version runs in serial and takes around 30 times longer to complete. Join ...
0
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0answers
93 views

Alternative to TEMPORARY tables capable of re-opening in a query?

I use TEMPORARY table for calculation of temporary data, but TEMPORARY tables in mysql has a big limitation, which made it useless for me. A table cannot be re-opened in a query. This mean I cannot ...
1
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1answer
936 views

UPDATE a column by COUNT of another table

It might be a naive question, but what is the difference of these two queries and which is preferred? UPDATE table1, (SELECT id,COUNT(*) idcount FROM table2 GROUP BY id) AS B SET table1.Freq = ...
1
vote
1answer
458 views

How to get MySQL to iterate a subquery in an aggregate select?

Because the vocabulary describing what I'd like to do can be so disparate, I haven't had any luck figuring out why MySQL 5.6 is doing what it does. Consider the following two simple queries: #1 ...
2
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0answers
442 views

Postgres Case statement not return else value in this query

I'm creating a SQL query with a some nested queries and I'm trying to use the CASE statement but it is behaving weirdly. I've been at it for at least 6 hours without any luck... This is my query at ...
1
vote
1answer
518 views

Using OFFSET in a large table by a simple sub-query

The slow performance for using OFFSET in large table has been widely discussed in various blogs, and the most efficient way is to use an INNER JOIN as SELECT * FROM table INNER JOIN ( SELECT id FROM ...
1
vote
1answer
159 views

How to UPDATE a column by COUNT of FK from another table?

How to extend this query for the entire table, to update all ids? UPDATE table1 SET number=( SELECT COUNT(*) FROM table2 where id=1 ) WHERE id=1 id is the PRIMARY KEY in table1 and FK in table2. ...
0
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1answer
88 views

Combine results from two queries?

I need to combine the results from two queries into one result set and order them altogether. This is the working, raw SQL code I have: SELECT * FROM ( SELECT t1.id AS entity_id, ...
0
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1answer
155 views

Optimizing multiple MySQL sub-queries and joins for multiple runs

The query (below) that's running is taking ~0.6 sec which normally would be fine but it gets run almost 1300 times for different custids. How can I make it run faster? Setup: Mac OS X 10.7.5 MySQL ...
0
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1answer
384 views

Find nearest values from MySQL Table

I want to fetch nearest rates for a given value from below table. mysql> select * from rates; +------+----------+----------+ | ID | Type | Rate | +------+---------------------+ | 1 | ...