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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4
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1answer
11k views

Insert into table select * from table vs bulk insert

I just wanted to know that SQL Statement INSERT INTO TABLE1 SELECT * FROM TABLE2, will work same like bulk insert ? If no, Is there any way exclude index while inserting records. Process is inserting ...
0
votes
1answer
568 views

How do I perform a query on a dynamic list of tables?

I have a database named as ( conntrack ) with unknown amount of tables.I have a static table "tabidx" which has one column "date". The following table is static and its name is tabidx which provide ...
0
votes
1answer
61 views

How do I select the value with SERIAL data type in postgres [closed]

I want to know how to select values from a column that has SERIAL data type. I already try to do that but the output is like this 'Resource id #3', and not just '3' I use SERIAL so I dont have to ...
2
votes
2answers
81 views

MySQL - SELECT on MyISAM Table on index - Does table size (rowcount) matter?

I was arguing with a coworker if SELECT * WHERE t BETWEEN ? AND ? on a MyIsam table where t is an index is significantly slower for huge tables. The hypothetically returned dataset is always the same,...
0
votes
1answer
14 views

Numeric cell with 0 not null

I have the following query (in a Oracle Database): SELECT SUM (CANTITATE) FROM ANEXA2A_TABEL2_ROWS WHERE TIP_ACTIUNE = 'COLECTATE' AND TIP_AMB = '...
0
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1answer
38 views

Grant Select on some columns for specific user

I have a windows group with 20 people and all 20 people in the group were revoked access for some columns in the table. Now I need to add the select permissions for 2 of the users in this windows ...
0
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2answers
50 views

Why does “DELETE WHERE (VARCHAR)=0” execute successfully?

DELETE FROM stats WHERE name=0 "name" is type VARCHAR(64). The above resulted in all records in the table being deleted, instead of just the 10~ that should have been affected. Only that many were ...
0
votes
1answer
141 views

The cost of left out join versus a select [closed]

I'm currently working with Ebean for database abstraction. My test database is Postgresql 9.3 I turned on logging for the SQL queries to test some code behavior. So, assume 2 tables, OneToMany ...
0
votes
1answer
156 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 ...
3
votes
1answer
10k views

how to fetch different data on compare rows of two tables

I have two tables in my database, one is user_app table in which user info are stored, table are as: +--------------+--------------+------+-----+-------------------+-----------------------------+ | ...
1
vote
1answer
65 views

Oracle: guaranteeing unmodified database state with queries?

If the first word of a SQL statement is either WITH or SELECT, is the statement guaranteed not to change the state of the database? i.e. is this loop "safe"? read SQL string if string begins with ...
-1
votes
1answer
104 views

SELECT rows with duplicate values

I have a table of names in mysql InnoDB as Firstname Lastname Steve Ross John Doe J. Doe Mike Ross Michael Ross Roger ...
1
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2answers
356 views

How to select data in the same table on different rows that are empty?

I use this select on my SQLite database: SELECT attributeX FROM table GROUP BY attributeX HAVING COUNT(attributeY) = 0; My table: attributeX (type integer) | attributeY (type text) ----------...
1
vote
1answer
5k views

MySQL Count rows from another table for each record in table

SELECT student.StudentID, student.`Name`, COUNT(attendance.AttendanceID) AS Total FROM student LEFT JOIN attendance ON student.StudentID = attendance.StudentID I am trying to count the last ...
0
votes
1answer
365 views

MySQL - How to replace a given value from multiple columns when using SELECT?

I need to SELECT a set of rows of a given table whose structure looks like - 1º line is the name of columns A01 A02 A03 A04 A05 ... A200 99999 99999 10 753 99999 ...
2
votes
2answers
2k views

MySQL - How to check whether all values of a given SELECTed row are equals? [closed]

Using MySQL, how can i SELECT all rows whose values are equals ? For instance, suppose a SELECT of a given table as follows COLUMN_A COLUMN_B COLUMN_C ... COLUMN_N 1 2 4 ...
2
votes
1answer
3k views

Mysql search matching multiple values in multiple columns

I need to speed up a search. Currently we let our users input a name: John Doe Then in Java we split that string to create multiple values (or "terms") ["John", "Doe"] and loop through the terms ...
2
votes
1answer
2k views

Reference column alias in same SELECT list

I'm converting an old MS-Access-based system to PostgreSQL. In Access, fields that were made up in SELECTs could be used as parts of equations for later fields, like this: SELECT samples.id, ...
0
votes
1answer
105 views

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) ...
-2
votes
2answers
114 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 ...
3
votes
3answers
273 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 ...
0
votes
1answer
85 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 s....
3
votes
1answer
588 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 ...
0
votes
1answer
32 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 hour'...
0
votes
0answers
45 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 [TestSat].[dbo].[Products]...
11
votes
4answers
5k 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 ...
0
votes
1answer
1k 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 ...
0
votes
0answers
35 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 ...
2
votes
1answer
253 views

Search within same ID across several rows

My table has the following structure: +----+---------+------------+-------------+ | id | word_id | meaning_id | sentence_id | +----+---------+------------+-------------+ | 1 | 1 | 15333 | ...
2
votes
3answers
1k 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 ...
1
vote
1answer
113 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 ...
0
votes
0answers
89 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) ...
28
votes
1answer
5k 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 * ...
0
votes
1answer
63 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 ...
0
votes
1answer
661 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 ...
5
votes
1answer
5k 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 ...
0
votes
1answer
27 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 ...
1
vote
1answer
380 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 ...
1
vote
2answers
531 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
votes
1answer
492 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
votes
1answer
113 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) works(...
0
votes
1answer
21 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. ...
1
vote
0answers
58 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; ...
0
votes
2answers
47 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 ...
1
vote
1answer
54 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 ...
2
votes
1answer
2k 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, m....
1
vote
0answers
247 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 -- ...
1
vote
1answer
3k 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 ...
0
votes
1answer
28 views

Copy every entry from TableA to TableB where the ID is in a textfile containing a list of IDs

I have a text file (or an xls) with a 35k lines, each containing a single ID. I'm required to copy every entry of TableA to TableB where the ID is in said list. Would it be best if I'd create a new ...
-2
votes
1answer
26k views

How to get MAX and MIN in GROUP BY query?

In a simple query SELECT col1, col2, col3 FROM table1 GROUP BY col1 each row includes the first value of col2 and col3 for each unique value of col. How to select MAX and MIN for each value of ...