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.

learn more… | top users | synonyms

1
vote
1answer
36 views

Get previous and next row from result set help

I have to get "relevant" results from a table by joining it on another table and filtering the results on parent id and current id, this all goes fine until your current id is either the first or the ...
0
votes
0answers
28 views

OFFSET in Transbase

I am working with Transbase DB and stuck on selection of specific range of rows. In MySQL I can do it as folows: SELECT * FROM table LIMIT 2,3; I know about FIRST() in Transbase, but how about ...
0
votes
0answers
47 views

How to give a prefix to all columns of a JOINed table in MySQL?

I have a data schema like this: car id type -> ENUM('Tesla', 'AstonMartin', 'Bmw') common_attribute car_tesla car_id specific_attribute_a specific_attribute_b ...
2
votes
1answer
53 views

How to JOIN a table with a name that equals to a determined value in MySQL?

The model of the (PHP & MySQL based) Zend Framework 2 application I’m currently working on contains a inheritance similar to the one described here. To map this to the database I’m using the ...
2
votes
3answers
113 views

Poor performance of JOIN, WHERE, ORDER BY combination (MySQL)

Goal: select 10 most recent rows from posts which are related to a specific user. There are two tables: posts (~5,000,000 rows) and relations (~8,000 rows). posts columns: --------------------------...
0
votes
2answers
46 views

Using Select Statement to get column name and table name from the same table

I have a table containing 2 Columns : Column1 (table_name) and column2 (column_name) like this : (Column 1) (Column 2) |Column_Name | Table_Name | -------------|------------| |...
0
votes
2answers
7k views

How to return a result set from oracle procedure ?

How can i return a result set from a stored procedure in oracle ? suppose i want to return a table from a simple select statement such as this : Select * from tblTest I tried this but this seems ...
0
votes
0answers
48 views

InnoDB: why “non-locking” SELECT still gets locked?

This issue can be related to my first question: InnoDB: very slow random updates, hanging in “updating” state But i think it needs to be clarified in a separate thread. The Problem: a simple read ...
0
votes
4answers
126 views

How can I use MySQL variables in subqueries?

I'm trying to run the following query, but it keeps getting "reduced" and failing. Cannot get MySQL to provide any information as to why. Here's the query: SELECT * FROM animals WHERE name IN(SELECT ...
0
votes
1answer
28 views

Expand a range columns into a single column

I'm thinking this is an easy query but I don't know how to start. I have a database table called Booklet with columns id, controlNoFrom and controlNoTo. Sample data looked like this: id | ...
1
vote
2answers
201 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||'''' ...
1
vote
1answer
66 views

MySQL INSERT … SELECT Performance

I know that this query will lock table2: UPDATE table1... SELECT .. FROM table2 How about this query ? INSERT INTO table1... SELECT .. FROM table2 Does this query also create a lock on table2?
0
votes
1answer
65 views

Subquery returns more than 1 row

I'm executing a query to return the products of a specific sale in Magento database. It's working fine for a sale that contains only one product, however, I'm having Subquery returns more than 1 row ...
0
votes
1answer
14 views

select duplicated rows by modified_date - PGSQL 9.2

Query: SELECT j.id INTO junk.ja_jobs FROM ( SELECT time_job, recurrenceid, clientid, creatortype, deleted, MIN(id) AS id FROM ja_jobs WHERE clientid = 33731 AND creatortype = 'legacyrec' AND ...
0
votes
2answers
34 views

MySQL - An UPDATE from a SELECT

The more I learn about about the great things you can do with mysql, the more I keep pushing to learn. I have two tables: Tests TestNumber (int primary key) InactiveTestSlotBitwise (int) ...
0
votes
2answers
67 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 ...
0
votes
1answer
45 views

INSERT and UPDATE in Trigger

I have created a trigger so I could insert every row in a backup table CREATE OR REPLACE TRIGGER xyz AFTER INSERT ON table_1 REFERENCING NEW AS NEW OLD AS OLD FOR EACH ROW BEGIN INSERT INTO table_2 (...
0
votes
1answer
8k views

How to create an Sql table from SELECT with a multiple row DISTINCT constraint?

I want to create a table from a SELECT statement based on a multiple row DISTINCT, but PostgreSQL does not allow me to do it. I need to create a table where the elements were previously selected from ...
3
votes
2answers
83 views

Inserting rows with WHERE condition

Structure 1 table named: scan 2 columns named: id, and date Problem I have two working queries, a SELECT and then an INSERT which I would like to merge together creating a INSERT where the ...
1
vote
1answer
60 views

Is there a way to find the partition or subpartition name where my ID belongs

I know if I need to select from any partition I need to provide partition name SELECT * FROM TABLE PARTITION(P1); What if I need to know which partition a particular value belongs using a sql query ...
3
votes
3answers
269 views

Listing rows with a WHERE condition

I am struggling with a SQL query that lists hosts that are offline. Problem The problem occurs when I need to list hosts that don't have any ports open (status = 0), so looking at the table at the ...
6
votes
2answers
38k views

How to JOIN two table to get missing rows in the second table

In a simple voting system as CREATE TABLE elections ( election_id int(11) NOT NULL AUTO_INCREMENT, title varchar(255), CREATE TABLE votes ( election_id int(11), user_id int(11), FOREIGN KEYs for ...
0
votes
1answer
32 views

Oracle : Is my DISTINCT function working properly?

I have alphanumeric values as my primary key. I am querying my database in two different ways and finding different results. It is almost certain that I might be missing some key point in my queries. ...
0
votes
2answers
75 views

MySQL SELECT n-th row between dates (time interval)

I have a server which records various sensor data each second and inserts it into a MySQL table. To view the sensor data on a dashboard I have a chart which also gets updated with live data each ...
1
vote
2answers
59 views

Counting rows from a subquery

Simple: I would like to count the number of rows from the sub-query. Note that status is whether the host is online or not. Bad code SELECT COUNT(ip_address) FROM `ports` ( SELECT DISTINCT ...
1
vote
2answers
102 views

how do I use a value from the select in a joined subquery?

I'm trying to avoid a stored procedure or bringing it into code but they may be my only alternatives. Here's my sql. Does anyone know any SQL voodoo that could make this happen without a stored ...
1
vote
1answer
51 views

SQL query returning cartesian and duplicates and not single records

So I have four tables as follows: CREATE TABLE softdrinks ( drinkID INT NOT NULL AUTO_INCREMENT, drinkName VARCHAR(100), PRIMARY KEY (drinkID) ); CREATE TABLE categories ( categoryID INT ...
-1
votes
1answer
38 views

Select and Insert for all data - Need help querying [closed]

At a first glance, this is my query INSERT INTO T2 SELECT T1.*, T3.DATETIME, T3.STATEID FROM T1 WHERE T3.DATETIME BETWEEN '01-NOV-15' AND SYSDATE LEFT OUTER JOIN T3 ON (T1....
1
vote
2answers
40 views

SQLPLUS: SELECT INTO prompting for variable value

Any idea why this is prompting me for the value? I'm calling the script via batch file: DECLARE precount NUMBER; nowcount NUMBER; BEGIN SELECT COUNT(*) INTO precount FROM ...
0
votes
1answer
61 views

MySQL: Select two values of two columns and compared their values exchanging them each other

I need to find a way to select one random row where the subscriber is not also leader (in the same or any other row). Something like this: (just to have an idea) SELECT `leader`,`subscriber` FROM `...
9
votes
1answer
12k views

Autoincrement primary key in CREATE TABLE … AS SELECT

I created table using a complicated select query via CREATE TABLE ... AS SELECT.... How can I add an autoincrement primary key in this query? For example: create table `user_mv` select `user`.`...
1
vote
1answer
72 views

SELECT query types and optimization

I'm using a database monitoring system that, amongst other data, shows the following values for SELECT queries: number of joins that use ranges on the first table number of joins that do a full scan ...
0
votes
1answer
20 views

Extract date and time separately from a time with time zone column [closed]

I have a table in PostgreSQL 9.3 with the following column ...., created_at time with time zone NOT NULL DEFAULT now(), ..., When I do a select created_at from trails; I get this "02:32:44.62054-...
1
vote
1answer
34 views

Is it possible to write a select * view that includes new columns added to table?

I would like to write a view that is essentially something simple select a + b, * from table_name and will always truly include all columns in table_name, even when I add or remove them. If I do the ...
0
votes
0answers
98 views

Select query keep showing “loading” message in phpMyAdmin

This query works fine: select * from prospect p JOIN prospect_company c ON p.prospect_id=c.prospect_id JOIN prospect_address a ON a.prospect_id=c.prospect_id; However, the following query keeps on ...
2
votes
2answers
6k 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.
0
votes
1answer
302 views

Simple select query taking too long

I have been having a hard time with this query, I have a webpage which is supposed to run this query a dozen of times, and with an execution time up to 40 - 50 seconds per query, you can see how this ...
16
votes
2answers
12k 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 ...
10
votes
2answers
18k views

What does the term “projection” refer to in an SQL query (or view definition)

In Oracle's document The Query Optimizer, under View Merging, I found the following information The view merging optimization applies to views that contain only selections, projections, and ...
2
votes
3answers
7k views

Select query takes more time than it should

I have a MySQL database table with nearly 23 million records. This table has no primary key, because nothing is unique. It has 2 columns, both are indexed. Below is its structure: Below is some of ...
1
vote
1answer
40 views

Error 1052 Field is Ambiguous using Inner Join Function

Error '1052' Field is ambiguous. I understand the error that is happening, and I've looked at several places for the fix and then applied the inner join function in attempt to fix it. It's still not ...
0
votes
1answer
50 views

Select and update specific mysql data in single query

I am trying to first select data from a row which contains certain characters. I would then like to update and append new data into another row of those items that were selected. This is my current ...
3
votes
2answers
6k views

How to COUNT number of rows with LIMIT?

I want to catch X rows, thus, I set LIMIT X; but how can I simultaneously count the total number of rows too? Currently, I use two separate queries to do so as SELECT COUNT(*) FROM col WHERE CLAUSE ...
5
votes
1answer
83 views

How to Choose Between VALUES and SELECT for INSERT?

This answer raised the question for me how to choose between VALUES and SELECT in such a function . Using PostgreSQL 9.4.3 on x86_64-unknown-linux-gnu, compiled by gcc (Debian 4.9.2-10) 4.9.2, 64-bit: ...
8
votes
4answers
43k views

Getting SELECT to return a constant value even if zero rows match

Consider this select statement: SELECT *, 1 AS query_id FROM players WHERE username='foobar'; It returns the column query_id with value 1 along with a player's other columns. How would ...
2
votes
2answers
197 views

How do I set the isolation level for SELECT statement?

Using PostgreSQL 9.5 I would like to make sure that when I run a SELECT statement I get consistent results, i.e. if the table is modified while the SELECT is running, I want to get the state that was ...
1
vote
2answers
25 views

How to select distinct record?

I have a table, as follows: ID | Name | MyID 1 | Alan | 2 2 | Alan | 2 3 | John | 3 I want to select the records as follows: If two records have the duplicate ...
2
votes
3answers
1k 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 ...
8
votes
2answers
45k 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 ...
3
votes
2answers
99 views

MySQL - Order by closest value on multiple columns

I have a table for a game lobby. In this lobby a user gets put in their connection and their level. In my SQL statement I am getting all the users in the lobby which are between +5/-5 of the user's ...