SQL filling a table importing data from another table and math - mysql

I am trying to develop software for one of my classes.
It is supposed to create a table contrato where I would fill the info of the clients and how much are they going to pay and how many payments they will make to cancel the contract.
On the other hand I have another table cuotas which should be filled by importing some info from table1 and I'm trying to perform the math and save the payment info directly into the SQL. But it keeps telling me I cant save the SQL because of error #1241
I'm using PHPMyAdmin and Xampp
Here is my SQL code
INSERT INTO `cuotas`(`Ncontrato`, `Vcontrato`, `Ncuotas`) SELECT (`Ncontrato`,`Vcontrato`,`Vcuotas`) FROM contrato;
SELECT `Vcuotaunit` = `Vcontrato`/`Ncuotas`;
SELECT `Vcuotadic`=`Vcuotaunit`*2;
Can you please help me out and fix whatever I'm doing wrong?

Those selects are missing a FROM clause.
So it's unknown from which table or view they have to take the columns.
You could use an UPDATE after that INSERT.
INSERT INTO cuotas (Ncontrato, Vcontrato, Ncuotas)
SELECT Ncontrato, Vcontrato, Vcuotas
FROM contrato;
UPDATE cuotas
SET Vcuotaunit = (Vcontrato/Ncuota),
Vcuotadic = (Vcontrato/Ncuota)*2
WHERE Vcuotaunit IS NULL;
Or use 1 INSERT that also does the calculations.
INSERT INTO cuotas (Ncontrato, Vcontrato, Ncuotas, Vcuotaunit, Vcuotadic)
SELECT Ncontrato, Vcontrato, Vcuotas,
(Vcontrato/Ncuota) as Vcuotaunit,
(Vcontrato/Ncuota)*2 as Vcuotadic
FROM contrato;

Related

Rails - How to reference model's own column value during update statement?

Is it possible to achieve something like this?
Suppose name and plural_name are fields of Animal's table.
Suppose pluralise_animal is a helper function which takes a string and returns its plural literal.
I cannot loop over the animal records for technical reasons.
This is just an example
Animal.update_all("plural_name = ?", pluralise_animal("I WANT THE ANIMAL NAME HERE, the `name` column's value"))
I want something similar to how you can use functions in MySQL while modifying column values. Is this out-of-scope or possible?
UPDATE animals SET plural_name = CONCAT(name, 's') -- just an example to explain what I mean by referencing a column. I'm aware of the problems in this example.
Thanks in advance
I cannot loop over the animal records for technical reasons.
Sorry, this cannot be done with this restriction.
If your pluralizing helper function is implemented in the client, then you have to fetch data values back to the client, pluralize them, and then post them back to the database.
If you want the UPDATE to run against a set of rows without fetching data values back to the client, then you must implement the pluralization logic in an SQL expression, or a stored function or something.
UPDATE statements run in the database engine. They cannot call functions in the client.
Use a ruby script to generate a SQL script that INSERTS the plural values into a temp table
File.open(filename, 'w') do |file|
file.puts "CREATE TEMPORARY TABLE pluralised_animals(id INT, plural varchar(50));"
file.puts "INSERT INTO pluralised_animals(id, plural) VALUES"
Animal.each.do |animal|
file.puts( "( #{animal.id}, #{pluralise_animal(animal.name)}),"
end
end
Note: replace the trailing comma(,) with a semicolon (;)
Then run the generated SQL script in the database to populate the temp table.
Finally run a SQL update statement in the database that joins the temp table to the main table...
UPDATE animals a
INNER JOIN pluralised_animals pa
ON a.id = pa.id
SET a.plural_name = pa.plural;

OPENQUERY SQL Server MYSQL UPDATE

I have to work on a linked server. My goal: Update an entire table in mysql server(version:8.0.21) via OPENQUERY in SQL Server(version 13.0.1742.0). I tried this but it generates an error Row cannot be located for updating. Some values may have been changed since it was last read and this one The rowset was using optimistic concurrency and the value of a column has been changed after the containing row was last fetched or resynchronized.
update linkedTable
set
linkedTable.id_parent=unlinkedTable.IdCat1,
linkedTable.code=unlinkedTable.CodeFamilleFAT,
linkedTable.niveau=unlinkedTable.NiveauCategorieFAT,
linkedTable.langue=unlinkedTable.CodeLangueFAT,
linkedTable.nom=unlinkedTable.LibelleCommercialFAT,
linkedTable.descriptionA=unlinkedTable.DescriptifCom1FAT,
linkedTable.vignette=null,
linkedTable.id_categorie=unlinkedTable.id
from openquery(NAMELINKEDSERVER, 'select id_categorie, id_parent, code, niveau, langue, nom, description as descriptionA, vignette from DatabaseMySQL.Table') as linkedTable
inner join DatabaseSQLserver.dbo.Table as unlinkedTable on unlinkedTable.Id = linkedTable.id_categorie
Then I tried this:
update linkedTable
set
linkedTable.id_parent=unlinkedTable.IdCat1,
linkedTable.code=unlinkedTable.CodeFamilleFAT,
linkedTable.niveau=unlinkedTable.NiveauCategorieFAT,
linkedTable.langue=unlinkedTable.CodeLangueFAT,
linkedTable.nom=unlinkedTable.LibelleCommercialFAT,
linkedTable.descriptionA=unlinkedTable.DescriptifCom1FAT,
linkedTable.vignette=null,
linkedTable.id_categorie=unlinkedTable.id
from openquery(NAMELINKEDSERVER, 'select id_categorie, id_parent, code, niveau, langue, nom, description as descriptionA, vignette from DatabaseMySQL.Table') as linkedTable
inner join DatabaseSQLserver.dbo.Table as unlinkedTable on unlinkedTable.Id = linkedTable.id_categorie
where linkedTable.id_categorie = 1
This work but only one row is updated. So I wrote a stored procedure to update each line but it took too much time.
Can someone explain why my first query didn't work (question1) and how I can reduce the time of my stored procedure (question2)?
I use while loop (count the number of id and update each id).
Thank you in advance.
Kind Regards.
I resolve the problem by checking some option on ODBC Driver in MySQL and reading some forum. I check this box.
enter image description here
This option allows to avoid the errors quoted previously. With this option, i can update multiple values without error on join or other request. Thank you Solarflare and "Another guy" (i lost the name) for correcting me (EDIT A POST). Have nice day both.

Running Multiple Sql Commands in a Loop

I successfully executed the sql code below from an msql editor (phpmyadmin), testing it with one customer (where Customer No=1). I need to now run the sql script for all the customers.
START TRANSACTION;
INSERT INTO `addresses` (`AddressLine1`,`CityID`,`ProvStateCode`,`AddressPostCode`,`CountryIso`) SELECT `Bill To Address`,`Bill To City`,`Bill To Province`,`Bill Code`,`Country` FROM `pdx_customers` where `Customer No`=1;
SELECT #last_id := LAST_INSERT_ID();
SELECT `Customer No` FROM `pdx_customers`
INSERT INTO `customer_addresses` (`CustID`,`AddressID`,`AddressTypeID`) Values(1,#last_id,1);
COMMIT;
It seems I would need to create a stored procedure ? In a loop, I need to get the Customer No dynamically for each row in the pdx_customers table, and enter into the Values clause in the insert command, i.e Values(#CustID,#last_id,1). Not sure how I would do this ?
Any help would be appreciated.
Thanks
This is a really common problem, and I would say that doing a loop in sql is almost never a good idea. Here is another option, which you may or may not consider good as it does introduce a new column. I've used it in some apps I've done, and its made things very simple. Does depend on your use case though so it wont be for everyone.
1) Firstly, add a new column to the address table, call it something that wont be confused by anyone looking at the table like TempInsertId.
2) When writing the new address, include the CustomerId in the TempInsertId column
3) Now you can easily read the AddressId and CustomerId back and write it into the CustomerAddress table
4) If you wish, do a final update to set the TempInsertId back to null.
As I said, not advocating in all cases, but it can be a very simple solution to the problem.
You can use the below statement to create a loop:
start transaction;
while counter < max do
insert into . . . ;
set counter=counter+1;
end while;

phpmyadmin SQL query multiple tables

I have two tables.
(1) compressors
(2) crankcase_heaters
I'm trying to create a SQL query to do:
Select the compressor.VOLTAGE and compressor.WATT of each compressor.PART_NUMBER
Find the crankcase_heater.PARTNO that has the same voltage and watts.
Add that value into a new field on the compressor table called "CRANKHTR"
Essentially this query will reproduce my compressors table but will have another 'column' called "CRANKHTR".
I'm completely lost on where to even start with this. I tried using the phpmyadmin SQL Query builder but i have no idea where to begin.
Without seeing the exact data structure, it sounds like you need a simple INNER JOIN:
SELECT
`cp`.`VOLTAGE`,
`cp`.`WATT`,
`ch`.`PARTNO` as CRANKHTR
FROM
`compressor` cp
INNER JOIN `crankcase_heaters` ch ON ch.VOLTAGE = cp.VOLTAGE AND ch.WATT = cp.WATT

Select from View using Where clause to refer to another database - Unknown Column error

I am trying to select certain values from a view that I created. The statement is below:
SELECT * FROM dashboard.team
WHERE ac2012.acx_users.id = 1;
As you can see, there are 2 databases being referenced here:
dashboard database, team table
ac2012 database, acx_users.id table
ac2012.acx_users.id is the regular expression in the original Create View statement, I'm using that since of course I can't use an ALIAS in a Where clause... however, this is showing an error:
Error Code 1054: Unknown column 'ac2012.acx_users.id' in 'where clause'
I'm not sure how to get this to work, because I need to reference the other database in this case, but it's not recognizing the database. Any tips would be appreciated.
Since you're selecting from a view, the underlying databases aren't visible anymore. You only see what the view presents, as part of the database which the view lives in, so try WHERE acx_users.id = 1, or whatever you've aliased that field to in the view definition.
SELECT * FROM dashboard.team
LEFT OUTER JOIN ac2012 ON ac2012.CommonColumnName=dashboard.CommonColumnName
WHERE ac2012.acx_users.id = 1;
======================
Please replace by original column name ...