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
Related
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;
I've this code:
SELECT VISA41717.Fraud_Post_Date, VISA41717.Merchant_Name_Raw, VISA41717.Merchant_City, VISA41717.Merchant_Country, VISA41717.Merchant_Category_Code, VISA41717.ARN, VISA41717.POS_Entry_Mode, VISA41717.Fraud_Type, VISA41717.Local_Amt, VISA41717.Fraud_Amt, VISA41717.Purch_Date, VISA41717.Currency_Code, VISA41717.Cashback_Indicator, VISA41717.Card_Account_Num
FROM VISA41717 LEFT JOIN MASTERCARD_VISA ON VISA41717.ARN=MASTERCARD_VISA.MICROFILM_NUMBER
WHERE VISA41717.ARN IS NULL OR MASTERCARD_VISA.MICROFILM_NUMBER IS NULL
ORDER BY VISA41717.ARN;
this is really works, But I need to match the first 6 digit of VISA41717.Card_Account_Num from BIN.INT to get the other data from BIN table and combined it all in one table only.
it should be this way:
Can you help me with this.
thanks!
What do you mean by 'all in one table'? Just build a query that joins tables.
Try:
SELECT ... FROM VISA41717 RIGHT JOIN BIN ON Left(VISA41717.Card_Account_Num, 6) = Bin.Int ...
Won't be able to build this join in Design View, use SQL View. Or build a query object that creates a field by extraction of the 6 characters and then build another query that includes that query and MASTERCARD_VISA and BIN tables.
I have a table in my MySQL database, compatibility_core_rules, which essentially stores pairs of ids which represent compatibility between parts which have fields with those corresponding ids. Now, my aim is to get all possible compatibility pairs by following the transitivity of the pairs (e.g. so if the table has (1,2) and (2,4), then add the pair (1,4)). So, mathematically speaking, I'm trying to find the transitive closure of the compatibility_core_rules table.
E.g. if compatibility_core_rules contains (1,2), (2,4) and (4,9), then initially we can see that (1,2) and (2,4) gives a new pair (1,4). I then iterate over the updated pairs and find that (4,9) with the newly added (1,4) gives me (1,9). At this point, iterating again would add no more pairs.
So my approach is to create a view with the initial pairs from compatibility_core_rules, like so:
CREATE VIEW compatibility_core_rules_closure
AS
SELECT part_type_field_values_id_a,
part_type_field_values_id_b,
custom_builder_id
FROM compatibility_core_rules;
Then, in order to iteratively discover all pairs, I need to keep replacing that view with an updated version of itself that has additional pairs each time. However, I found MySQL doesn't like me referencing the view in its own definition, so I make a temporary view (with or replace, since this will be inside a loop):
CREATE OR REPLACE VIEW compatibility_core_rules_closure_temp
AS
SELECT part_type_field_values_id_a,
part_type_field_values_id_b,
custom_builder_id
FROM compatibility_core_rules_closure;
No problems here. I then reference this temporary view in the following CREATE OR REPLACE VIEW statement to update the compatibility_core_rules_closure view with one iteration's worth of additional pairs:
CREATE OR REPLACE VIEW compatibility_core_rules_closure
AS
SELECT
CASE WHEN ccr1.part_type_field_values_id_a = ccr2.part_type_field_values_id_a THEN ccr1.part_type_field_values_id_b
WHEN ccr1.part_type_field_values_id_a = ccr2.part_type_field_values_id_b THEN ccr1.part_type_field_values_id_b
END ccrA,
CASE WHEN ccr1.part_type_field_values_id_a = ccr2.part_type_field_values_id_a THEN ccr2.part_type_field_values_id_b
WHEN ccr1.part_type_field_values_id_a = ccr2.part_type_field_values_id_b THEN ccr2.part_type_field_values_id_a
END ccrB,
ccr1.custom_builder_id custom_builder_id
FROM compatibility_core_rules_closure_temp ccr1
INNER JOIN compatibility_core_rules_closure_temp ccr2
ON (
ccr1.part_type_field_values_id_a = ccr2.part_type_field_values_id_a OR
ccr1.part_type_field_values_id_a = ccr2.part_type_field_values_id_b
)
GROUP BY ccrA,
ccrB
HAVING -- ccrA and ccrB are in fact not the same
ccrA != ccrB
-- ccrA and ccrB do not belong to the same part type
AND (
SELECT ptf.part_type_id
FROM part_type_field_values ptfv
INNER JOIN part_type_fields ptf
ON ptfv.part_type_field_id = ptf.id
WHERE ptfv.id = ccrA
LIMIT 1
) !=
(
SELECT ptf.part_type_id
FROM part_type_field_values ptfv
INNER JOIN part_type_fields ptf
ON ptfv.part_type_field_id = ptf.id
WHERE ptfv.id = ccrB
LIMIT 1
)
Now this is where things go wrong. I get the following error:
#1146 - Table 'db509574872.compatibility_core_rules_closure' doesn't exist
I'm very confused by this error message. I literally just created the view/table only two statements ago. I'm sure the SELECT query itself is correct since if I try it by itself and it runs fine. If I change the first line to use compatibility_core_rules_closure2 instead of compatibility_core_rules_closure then it runs fine (however, that's not much use since I need to be re-updating the same view again and again). I've looked into the SQL SECURITY clauses but have not had any success. Also been researching online but not getting anywhere.
Does anyone have any ideas what is happening and how to solve it?
MySQL doesn't support sub-queries in views.
You'll have to separate them... ie. using another view containing the sub-query inside you main view.
Running the create statement for that view will render an error, not creating it, hence the doesn't exist error you're getting when querying it.
before i use alias for table i get the error:
: Integrity constraint violation: 1052 Column 'id' in field list is ambiguous
Then i used aliases and i get this error:
unknown index a
I am trying to get a list of category name ( dependant to a translation) and the associated category id which is unique. Since i need to put them in a select, i see that i should use the lists.
$categorie= DB::table('cat as a')
->join('campo_cat as c','c.id_cat','=','a.id')
->join('campo as d','d.id','=','c.id_campo')
->join('cat_nome as nome','nome.id_cat','=','a.id')
->join('lingua','nome.id_lingua','=','lingua.id')
->where('lingua.lingua','=','it-IT')
->groupby('nome.nome')
->lists('nome.nome','a.id');
The best way to debug your query is to look at the raw query Laravel generates and trying to run this raw query in your favorite SQL tool (Navicat, MySQL cli tool...), so you can dump it to log using:
DB::listen(function($sql, $bindings, $time) {
Log::info($sql);
Log::info($bindings);
});
Doing that with yours I could see at least one problem:
->where('lingua.lingua','=','it-IT')
Must be changed to
->where('lingua.lingua','=',"'it-IT'")
As #jmail said, you didn't really describe the problem very well, just what you ended up doing to get around (part of) it. However, if I read your question right you're saying that originally you did it without all the aliases you got the 'ambiguous' error.
So let me explain that first: this would happen, because there are many parts of that query that use id rather than a qualified table`.`id.
if you think about it, without aliases you query looks a bit like this: SELECT * FROM `cat` JOIN `campo_cat` ON `id_cat` = `id` JOIN `campo` ON `id` = `id_campo`; and suddenly, MySQL doesn't know to which table all these id columns refer. So to get around that all you need to do is namespace your fields (i.e. use ... JOIN `campo` ON `campo`.`id` = `campo_cat`.`id_campo`...). In your case you've gone one step further and aliased your tables. This certianly makes the query a little simpler, though you don't need to actually do it.
So on to your next issue - this will be a Laravel error. And presumably happening because your key column from lists($valueColumn, $keyColumn) isn't found in the results. This is because you're referring to the cat.id column (okay in your aliased case a.id) in part of the code that's no longer in MySQL - the lists() method is actually run in PHP after Laravel gets the results from the database. As such, there's no such column called a.id. It's likely it'll be called id, but because you don't request it specifically, you may find that the ambiguous issue is back. My suggestion would be to select it specifically and alias the column. Try something like the below:
$categories = DB::table('cat as a')
->join('campo_cat as c','c.id_cat','=','a.id')
->join('campo as d','d.id','=','c.id_campo')
->join('cat_nome as nome','nome.id_cat','=','a.id')
->join('lingua','nome.id_lingua','=','lingua.id')
->where('lingua.lingua','=','it-IT')
->groupby('nome.nome')
->select('nome.nome as nome_nome','a.id as a_id') // here we alias `.id as a_id
->lists('nome_nome','a_id'); // here we refer to the actual columns
It may not work perfectly (I don't use ->select() so don't know whether you pass an array or multiple parameters, also you may need DB::raw() wrapping each one in order to do the aliasing) but hopefully you get my meaning and can get it working.
I have a problem with a MySQL WHERE clause. I think I know what the problem is, just not how to fix it.
I have a database with student timetable information and I'm matching this against a table with student information. The student information has been imported into the database from a CSV (utf-8) file, the other information was just inserted into the database with "normal" INSERT queries.
The WHERE clause is simple and looks like this:
WHERE gpu_timetable.cls_name =
(SELECT cls_name FROM gpu_students WHERE std_number = 123441 LIMIT 1)
Its matching the cls_name (class name) from the timetable against the class name from the students table. Like I said the data is from different sources but looks to be the same. For example when I remove the SELECT query and use this string ('LV6A') the code works.
The collation on both of the fields is *utf8_general_ci*, I also tried TRIM() but no success, the same for replacing the operator = with LIKE.
Did I do something wrong when importing the student information or is there another function similar to TRIM() that can fix this weird problem?
Your simplified query must be:
SELECT * FROM gpu_timetable INNER JOIN gpu_students ON gpu_timetable.cls_name = gpu_students.cls_name WHERE gpu_students.std_number = 123441
Your should always have tablename.fieldname while using JOIN queries.