MySQL Dual table Join Dual table

MySQL Dual table Join Dual table

By : BrettH
Date : November 22 2020, 10:31 AM
wish help you to fix your issue Is there a way to JOIN fields from the dummy DUAL table in MySQL? , Here's one way...
code :
Select t1.n1, t2.n2 
from (select 1 as n1) t1 
CROSS JOIN (Select 2 as n2) t2;
Select t1.n1, t2.n2 
from (select 1 as n1, 'A' as ID) t1 
INNER JOIN (Select 2 as n2, 'A' as ID) t2
  on T1.Id = T2.ID;
Select 1 as n1, 2 as n2

Share : facebook icon twitter icon
MySQL Partitioning Join Table (Dual PK)

MySQL Partitioning Join Table (Dual PK)

By : Kimiyoshi Hosoi
Date : March 29 2020, 07:55 AM
To fix the issue you can do Problem was the dual primary key. As a dual, it basically had to look at every record in the join table. I added a single key for tag_id and a single key for image_id and it drastically improved the speed. Machavity!
Mysql count, join, and dual in conjunction

Mysql count, join, and dual in conjunction

By : Yaroslav
Date : March 29 2020, 07:55 AM
I wish did fix the issue. I have a table tester which has a primary id and a foreign key that references the id of a table called test. , I would write your query like this:
code :
INSERT INTO tester (test, createddate, ipaddress) 
  test.ID, NOW(), 'xxx.xxx.xxx.xxx'
  test.ID = 1
              FROM tester
              WHERE tester.test = test.ID
              HAVING test.numAllowed-COUNT(*)>0);
MySQL insert multiple rows into empty table using SELECT FROM DUAL WHERE NOT EXISTS

MySQL insert multiple rows into empty table using SELECT FROM DUAL WHERE NOT EXISTS

By : user3564594
Date : March 29 2020, 07:55 AM
will be helpful for those in need I am using this code to insert a default row if the table is definitely empty. I am trying to extend this to insert multiple rows but cannot figure out the syntax: , Something like this should work:
code :
CREATE TEMPORARY TABLE `myDefaults` ( the_value INT|VARCHAR|whatever... )
INSERT INTO myDefaults (the_value) VALUES (myVal1), (myVal2), ....

SET @valCount := 0; -- Because I am paranoid ;)
SELECT COUNT(1) INTO @valCount FROM myTable;

INSERT INTO myTable(myCol)
SELECT the_value 
FROM myDefaults 
WHERE @valCount = 0

Inserting new id from sequence into table column id and insert that same id to another table without dual table

Inserting new id from sequence into table column id and insert that same id to another table without dual table

By : kajak
Date : March 29 2020, 07:55 AM
this one helps. I'm posting solution where I use kartica_seq as a sequence for kartica_id. Please replace it with your sequence name or create sequence if it not exist.
create sequence kartica_seq start with 1 increment by 1;
code :
create or replace procedure insertOsoba
   ( o_osoba_id in osoba.osoba_id%type default generate_id.nextval,
     o_ime_osobe in osoba.ime_osobe%type,
     o_prezime_osobe in osoba.prezime_osobe%type,
     o_kartica_id in kartica.kartica_id%type default null --must be optional
cnt number;
cnt2 number;
      select count(*) into cnt from osoba where kartica_id = o_kartica_id;
      select count(*) into cnt2 from kartica where kartica_id = o_kartica_id;
      if(cnt = 0) then
        --there is no person with such kartica and user passed existing kartica_id
        if(o_kartica_id is not null and cnt2 > 0) then
          insert into osoba (osoba_id,ime_osobe,prezime_osobe,kartica_id)
          values (o_osoba_id,o_ime_osobe,o_prezime_osobe,o_kartica_id);
        --there is no person with such kartica but we need to create one entry using sequence
          insert into kartica (kartica_id) values (kartica_seq.nextval);
          insert into osoba (osoba_id,ime_osobe,prezime_osobe,kartica_id)
          values (o_osoba_id,o_ime_osobe,o_prezime_osobe,kartica_seq.currval);
        end if;
      end if;
      --there is person with such kartica
      if(cnt > 0) then
        dbms_output.put_line('Kartica_id already exists. No same values allowed.'); --or raise an exception here
      end if;
end insertosoba;
Is it possible to include dual table in a join query

Is it possible to include dual table in a join query

By : MadGeek
Date : March 29 2020, 07:55 AM
Hope this helps One common use (for me) is to use it to make inline views to join on...
Related Posts Related Posts :
  • How to handled the null values in WHERE IN condition in mysql
  • Is it okay to update primary key field to shift a record to the top?
  • Stop query through pdo
  • How to check whether particular value in field in MySQL exists
  • Execute a statement for every table in a database
  • insertion 74G data into mysql table cost more then 2 days, how to improve insert performance
  • Where can I see the differents "Hibernate Console Configurations" in Eclipse
  • MySql | relational database vs non relational database in terms of Performance
  • Exporting mysql database using mysqldump including procedures
  • Trigger MySQL not working
  • How do I update values for individual rows quickly?
  • MySQL join query with multiple where condition
  • MySQL stored procedure is not working
  • MySQL - Order By exact match at the end
  • Select max date or null date from same table MySQL
  • Best solution workaround for needing a mysql event on insert?
  • MySQL select several columns of several tables at the same time without using JOIN
  • Is it more efficient to have a table with one of its columns mostly empty or make a new table and refer to it?
  • mysql data truncated with ñ character
  • MySQL Distinct Active Users for the last month query
  • Get all rows that match another attribute in the same table
  • MySQL statement to get min value with max ID
  • DATEDIFF Current/Date for Last Record
  • What is the logic or procedure for combining multiple DB query's results into one elegant table?
  • Modify TIMESTAMP MySQL for use as Primary Key
  • Django - Efficiently bulk create inherited models
  • Ruby on Rails - database where sorted by id
  • MySQL 5.6 : Access denied for user 'root' @ 'localhost' when password contains backslash
  • sql query case dateadd
  • Click on one button multiple times and mySql
  • Select daily amount of specific values from same column
  • How to send e-mail to users within a database?
  • Updating self joined table
  • Convert query to a Left-Join (?) to include userid's without a match
  • How to Convert from .Net TimeZone to MySQL TimeZone
  • Syntax Error for MySQL Trigger
  • SQL Optimization - 3 Tables - Multiple SUMs - 20k records - 12 Seconds
  • MySQL: Why does query give NULL as a result of SUM?
  • Simple query issue with multiple tables and mismatching IDs
  • MySQL join multiple lines
  • Performing JOIN between two tables
  • Get specific rows from group by clause in PostgreSQL
  • MySQL query to get the sum of a column
  • Why mongoDB takes less time for Select than Fetch time?
  • Laravel 4.2 BIT datatype issue
  • MySQL Join Query confuse
  • Select distinct rows by count in descending order
  • Select query with comma and join
  • Adding a percentage (%) sign to each value while using select sql statement
  • How to access data from foreign key table
  • How to use the SQL MINUS keyword
  • Mysql Left Join statement ignored during query
  • Mysql version is different in phpmyadmin
  • MySQL: creating comma separated list and using in IN
  • calculating total time using timestamp
  • SQL LIKE REGEXP Matching Single Value and Comma'd String
  • one table or several table in mysql
  • Selecting rows with null in integer columns using mysql query
  • Using MySQL Database Triggers
  • Trying to get TOP 10 products per sales channel
  • shadow
    Privacy Policy - Terms - Contact Us © ourworld-yourmove.org