A core SQL statement, SELECT retrieves data from one or more tables or other sources of row set data such as views or table-valued functions.

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on every row on SELECT Query must lookup to other table

I'm working on Login/Logout System and I'm facing this problem regarding on SELECT Query. I have 2 tables namely dtr_tbl and shift_tbl. In dtr_tbl are the logs of the user(login/logout time details) ...
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18 views

Select range of non-identical date from different table

On MySQL5 with innoDB, I have sensor data in multiple tables, all with an ID and a DATETIME field, like so (two tables shown, but there are more). The IDs and DATETIMEs are not identical between ...
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2answers
23 views

SQL SUM of different product groups in one query?

I have a table with the following columns: PRODUCT_ID | PRODUCT_NAME | GROUP_ID | GROUP_NAME | PRICE GROUP_ID and GROUP_NAME are not UNIQUE. Can I make a selection which just returns each GROUP_ID ...
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37 views

CONCURRENT SELECT's SLOW … LOCK IN SHARE MODE

My Table has 25 Million rows total and 6 million rows satisfying below where clause. Select 1: select max(stamp) from Table where type = "string" LOCK IN SHARE MODE ; 6000+ seconds Select 2: ...
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1answer
152 views

SQL SELECT - adding field to SELECT with JOIN is changing the results

I have a SQL sentence with JOIN, running on mysql 5.5.16: SELECT DISTINCT (ot.orders_id), ot.value FROM orders_status_history osh INNER JOIN orders_total ot ON ( osh.orders_id = ot.orders_id ) WHERE ...
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646 views

Getting the top count of records from a table for each month and user

I have a table where translations are stored along with the user_id and when the translation was added. I want to create a query that shows the 'Translator of the month' (the person who did the most ...
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3answers
51 views

How does like query work with indexed table

I am working in Spring-java and mysql. I have to query the table of size 100k records. Table has say 10 columns. And In my sql select query I have to make like queries with %text% search on say 4 ...
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25 views

Replace nested “select with count” with outer join? is this possible?

SELECT c.classid , c.classname , (select count(s.id) from students s where s.classid = c.classid and status = 'failed') as noOfFailed, (select count(s.id) from students s where ...
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114 views

Select * from (every table in an subselect)

I was trying to get an select * from (for column table result) every table_name with the result bellow, how can i achieve this? (SELECT a.table_name FROM all_cons_columns a JOIN all_constraints c ...
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1answer
22 views

MySQL: What exact commands does each privilege level allow?

I am configuring some new logins for users who have already been using the relevant MySQL servers under other logins. I would like to limit their privileges to the minimum each user needs, based on ...
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1answer
45 views

Better way to select from nested tables in PostgreSQL

I have the following schema with millions of rows in the match table and each match have two sides (away and home). I want to create a view which shows the most significant data regarding the matches ...
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22 views

Padding MySQL queries

I'm trying to retrieve logs of our plant where a certain event has occurred. At the moment, I can query the actual event by using an alarm_code field. However, I'd also like to include about an ...
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46 views

Alternatives to Linked Servers (Allow Inline SQL with Parameters)

I am trying to find a solution to execute inline SQL with parameters against some liked server databases. From what I have found online the only proper way to query a linked server is to use ...
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0answers
41 views

What is the difference between normal Select query and a Select query inside Common Table Expression(CTE)? [duplicate]

I'm having a table 'Products' and if Execute this query SELECT TOP 1000 [ProductID] ,[ProductDesc] ,[ManufacturingDate] ,[ExpiryDate] ,[Price] FROM ...
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1answer
108 views

Speeding up a simple select query on Mariadb

I have a 100k rows table with the following structure: +----------+------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | ...
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4answers
3k views

Benefits of using backtick (`) in MySQL queries?

In MySQL we can create queries with or without the backtick (`) symbol. Example: SELECT * FROM TEST; SELECT * FROM `TEST`; Both works fine in mysql-console. Is there any technical difference ...
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1answer
25 views

Slow query while selecting a higher offset from millions of rows

I have sort of security log files containing millions of rows. On my current testing I imported the data for one month which is the sum of ~14,000,000 records. The table contains several set of fields ...
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1answer
59 views

Select rows from table where each row refers to a different schema

I have customer table in public schema. And I have a schema named after each customer. Each customer schema contains different tables like portals, plugin, ... When I want to select portals used by ...
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1answer
140 views

How can I optimize this Cross Table COUNT() mysql query?

I am trying to cut down the retrieval speed of this MySQL query. All instances of COUNT() point to the PRIMARY key of each field. Currently this query makes my MySQL hang. It seems ridiculous as I'm ...
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34 views

How to fetch data on a single column from a table having composite key [duplicate]

I am working on a messaging application, where the users can have a group conversation with multiple recipients. So in my database, I have a table called user_message where user_id and message_id is ...
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2answers
46 views

Searching a database safely using SELECT

I have a site that allows users to search the database for several items. However I am not that good with SQL and I have read that allowing user to type in boxes that then use "SELECT-statements" is ...
2
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1answer
161 views

Search within same ID across several rows

My table has the following structure: +----+---------+------------+-------------+ | id | word_id | meaning_id | sentence_id | +----+---------+------------+-------------+ | 1 | 1 | 15333 | ...
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3answers
312 views

How to speed up a multiple select query

EDIT - Putting my whole stored procedure: I have the below stored procedure: CREATE PROCEDURE [dbo].[data_Update] @Owner NVARCHAR(255), @ID VARCHAR(255), @Division VARCHAR(255), @Manager ...
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2answers
17k views

SELECTing multiple columns through a subquery

I am trying to SELECT 2 columns from the subquery in the following query, but unable to do so. Tried creating alias table, but still couldn't get them. SELECT DISTINCT petid, userid, (SELECT ...
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34 views

SELECT from Function that return CURSOR

I would like to select from a function that return a SYS_REFCURSOR Type value. for example : CREATE OR REPLACE FUNCTION my_funtion ( my_param IN VARCHAR2) RETURN SYS_REFCURSOR IS ...
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2answers
51 views

How to split a row in a result into mutliple rows

I have the following query: SELECT vs.MonthName AS Month, vs.Region, vs.Category, CAST (MIN (a.TotalAmount) AS money) AS ActualAmount, MIN (a.TotalCases) AS ...
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48 views

How to insert the gathered dates into another table using INSERT SELECT in MySQL?

insert into rfdate (date) select adddate('1970-01-01',t4*10000 + t3*1000 + t2*100 + t1*10 + t0) selected_date from (select 0 t0 union select 1 union select 2 union select 3 union select 4 union select ...
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18 views

Use join to aggregate data from various normalized tables

I have a database as follows: tbl_clients (Primary Key: client_id, Foreign Keys:place_id,district_id,zone_id,country_id) tbl_places (Primary Key: place_id) tbl_districts (Primary key: district_id) ...
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1answer
3k views

USING construct in JOIN clause can introduce optimization barriers in certain cases?

It was brought to my attention that the USING construct (instead of ON) in the FROM clause of SELECT queries might introduce optimization barriers in certain cases. I mean this key word: SELECT * ...
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20 views

Need help on transferring data from a PostgreSQL database to a future (to be decided) database!

(English isn't my native language) I'm doing an internship for school and my task is to theoretically describe the best way to transfer the data from their current database (PostgreSQL) that they have ...
0
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1answer
36 views

select statement for subtype

Okay, so all I'm trying to do here is list the managers who supervised the employee that charged a customer $100 for a rental on November 1st, 1998. My issue is that I don't know how to select the ...
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45 views

Update does not working while select returns right results

I am trying to execute the query below: UPDATE( SELECT Ord.Completed FROM Product P INNER JOIN Order1 Ord ON Ord.OrderID = P.OrderID WHERE EXISTS( SELECT * FROM Delivery ...
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1answer
3k views

SELECT with large WHERE IN clause taking long time

I'm pretty new at all this so be gentle :). I have large medical DB where I need to extract data for patients based on selected doctor(s). Right now I build a patient list by SELECT patID FROM ...
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1answer
22 views

How to modify the below script to take tables and its sizes for a particular databse to send via mail to a recipient?

SELECT top 10 t.NAME AS TableName, (SUM(a.total_pages) * 8)/1024.0/1024.0 AS TotalSpaceGB FROM sys.tables t INNER JOIN sys.indexes i ON t.OBJECT_ID = i.object_id INNER JOIN ...
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24 views

MySQL: querying json

I have json text inside a MySQL table : [{"key_fiyat":"100.00"},{"key_fiyat_primi":"USD"},{"key_il":"33"}] now I want to select ... from table where key_il = 33 How can I do it in php ?
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73 views

How to make a single row result query to return multiple rows

I have the following WITH SQL Query which does select a set of filling stations along a route within the distance of 1000m. To have the measurement in meter I cast the geometries to geography. I also ...
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2answers
92 views

How to find all schemas where a table has records?

In my Oracle database, I have a number of schemas (users/owners) with similar table structures (about 100 in total). However, some tables are empty in a lot of schemas. Is there a way to find out for ...
2
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1answer
71 views

MySQL - Get Minimum Value, Data From Multiple Tables

Good evening all, first post on the DBA forums. I am having real issues working out how to accomplish a seemingly simple task within MySQL as a model for PHP code later on. I am not exactly a MySQL ...
0
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1answer
44 views

4 tables, find department with the highest average salary [closed]

ABC is an organization operating in a certain country. Below are the data for the database that manages the information on this organization's employees: employee(employee_name, street, city) ...
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1answer
17 views

Selecting one variant out of different similar results

I have a table that looks as follows: Book Format Contents A html ... A markdown ... B html ... C markdown ... I want to return only 1 version of a book. ...
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38 views

How to use the value from record like as varchar?

I'm trying update a old table with result of selec for another tables but get a error using this sintaxe (e.g.): DO $$ DECLARE _roles refcursor; _onerole varchar; _record RECORD; ...
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2answers
33 views

Get all the users that are managed by a targeted manager

I have the following model: Table user: (id, name, direct_manager_id) Table customer: (id, name, managed_by_id) i.e. users can have another user as their direct manager, Customers can be managed ...
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1answer
32 views

Creating a View with results from join of scalar tables

I am really bad at SQL Queries and seem to be stuck at a very odd problem. Maybe there's an alternative of doing this, but I simply can't figure it out. Maybe you guys can help! So, here's my ...
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2answers
2k views

To select from all tables inside the schema in PostgreSQL

Is it possible to select from all tables inside the schema? I got all the table names from select table_name from information_schema.tables but I am unable to use it to do my query.
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1answer
38 views

Need help in incrementing the date in oracle

Error thrown as "Invalid number" while trying to increment the date. Given below is the query executed through sqlplus. Please help me on this. select ''''||to_date(:To_date, 'dd-mon-yyyy')+1||'''' ...
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75 views

Processlist show most of the queries are sending data for select query

I have faced some problem like sending data state in processlist. In my application I used parallel processing which send 50 count at a time, and that will do some MySQL database operation (select and ...
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6k views

How to select specific rows if a column exists or all rows if a column doesn't

I'm writing a script that gets a count of rows for a few tables, however for some tables I want to only get a count of rows where a flag is set (in this case active=1). Is there a way I can do this ...
2
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1answer
81 views

How to speed up slow query using GROUP BY and CASE?

I'm not very experienced with MySQL and and trying to figure out how to speed up a slow query using GROUP BY and CASE statements. CASE 1 -- GROUP BY and CASE SELECT SQL_NO_CACHE m.id, m.sku, ...
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95 views

two column compare ,get count(*) of two column A value same cloumn B value

I have a Mysql table as --------------------- -- page - user -- --------------------- -- page a - user 1 -- -- page a - user 2 -- -- page a - user 3 -- -- page b - user 1 -- -- page b - user 3 -- ...
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1answer
88 views

Select into existing table where ID is in another table [closed]

I have one table containing ~35k IDs (TableC), one table that features multiple columns (TableA), amongst others the ID from the before mentioned table and a third empty table, featuring the same ...