MySQL multiquery gives errors, need to save variable - mysql

I have a table where I need to do two selections. First I need to find OBJ where uunn = abc. Then I need to select where OBJ equals the first result but it doesn't work.
Example:
SELECT OBJ INTO #obj FROM wddt WHERE `uunn`='abc' AND `mqr`='ps';
SELECT mqr FROM wddt WHERE `OBJ` = #obj AND `uunn`='as';
My goal is to check if mqr has a certain content, and I will compare that content in my PHP script.

Multi_query was disabled on the server I was trying to use, just tested everything using XAMPP and works like a charm. I didn't know multi-query could be disabled.

If you don't need the actual results of the first query you may use a subquery in the WHERE clause of the second one:
SELECT mqr FROM wddt WHERE `uunn`='as'
AND `OBJ` LIKE (SELECT OBJ FROM wddt WHERE `uunn`='abc' AND `mqr`='ps');

Related

JSON_VALUE not working in old version. is there any other way in SQL to get a value from a JSON

So the main problem I'm having is that I really need to get a value from another table that is in JSON format, obviously I thought, well just use JSON_VALUE to get the property I want... Problem arises when I created in adonis the migration, and surprise. After running the migrations I realise I can't use JSON_VALUE because of the version of adonis server. Is there another way I can get the value?
Well, it was easier than I'd expected. I could, because I wanted to search a String inside the JSON it was as easy as using LIKE. Example
user.settings was a JSON more less like:
'{"platform" : "windows"}'
UPDATE order
SET order.platform = (
SELECT
CASE
WHEN users.settings LIKE '%mac%' THEN 'mac'
WHEN users.settings LIKE '%windows%' THEN 'windows'
ELSE NULL
END
FROM users
WHERE users.id = orders.user_id
)

how to include hard-coded value to output from mysql query?

I've created a MySQL sproc which returns 3 separate result sets. I'm implementing the npm mysql package downstream to exec the sproc and get a result structured in json with the 3 result sets. I need the ability to filter the json result sets that are returned based on some type of indicator in each result set. For example, if I wanted to get the result set from the json response which deals specifically with Suppliers then I could use some type of js filter similar to this:
var supplierResultSet = mySqlJsonResults.filter(x => x.ResultType === 'SupplierResults');
I think SQL Server provides the ability to include a hard-coded column value in a SQL result set like this:
select
'SupplierResults',
*
from
supplier
However, this approach appears to be invalid in MySQL b/c MySQL Workbench is telling me that the sproc syntax is invalid and won't let me save the changes. Do you know if something like what I'm trying to achieve is possible in MySQL and if not then can you recommend alternative approaches that would help me achieve my ultimate goal of including some type of fixed indicator in each result set to provide a handle for downstream filtering of the json response?
If I followed you correctly, you just need to prefix * with the table name or alias:
select 'SupplierResults' hardcoded, s.* from supplier s
As far as I know, this is the SQL Standard. select * is valid only when no other expression is added in the selec clause; SQL Server is lax about this, but most other databases follow the standard.
It is also a good idea to assign a name to the column that contains the hardcoded value (I named it hardcoded in the above query).
In MySQL you can simply put the * first:
SELECT *, 'SupplierResults'
FROM supplier
Demo on dbfiddle
To be more specific, in your case, in your query you would need to do this
select
'SupplierResults',
supplier.* -- <-- this
from
supplier
Try this
create table a (f1 int);
insert into a values (1);
select 'xxx', f1, a.* from a;
Basically, if there are other fields in select, prefix '*' with table name or alias

Statement in trigger is not "picking up" the condition in its Where clause

so I'm currently working on a MySQL trigger. I'm trying to assign values to two variables when a new record is inserted. Below are the queries:
SET mssgDocNo = (SELECT Document_ID FROM CORE_MSSG WHERE Message_ID = new.MSSG_ID);
SET mssgRegime = (SELECT CONCAT (Regime_Type, Regime_Code) FROM T_DOC WHERE CD_Message_ID = new.MSSG_ID);;
For some reason, the second SQL query is not picking up the 'new.MSSG_ID' condition while the first query in same trigger recognizes it. I really can't figure out what seems to be the problem.
When I replace the 'new.MSSG_ID' with a hard-coded value from the database in the second query it seems to work. I doubt the 'new.MSSG_ID' is the problem because it works perfectly fine in the first query.
I've tried pretty much anything I could think of. Would appreciate the help.
I would write these more simply as:
SELECT mssgDocNo := Document_ID
FROM CORE_MSSG
WHERE Message_ID = new.MSSG_ID;
SELECT mssgRegime := CONCAT(Regime_Type, Regime_Code)
FROM T_DOC
WHERE CD_Message_ID = new.MSSG_ID;
The SET is not necessary.
I did make one other change that might make it work. I removed the space after CONCAT. Some versions of MySQL have trouble parsing spaces after function calls.

MySql explode/in_array functionalilty

In my table I have a field with data such as 1,61,34, and I need to see if a variable is in that.
So far I have this
SELECT id, name FROM siv_forms WHERE LOCATE(TheVariable, siteIds) > 0
Which works, with the exception that if the siteIds were 2,61,53, and TheVariable was 1, it would return the row as there is a 1 in 61. Is there anyway around this using native MySql, or would I need to just loop the results in PHP and filter the siteIds that way?
I've looked through the list of string functions in MySql and can't see anything that would do what I'm after.
Try with find_in_set function.
SELECT id, name FROM siv_forms WHERE find_in_set(TheVariable, siteIds);
Check Manual for find_in_set function.

Condition check with IN clause mysql

I have a string returned from a function "'aa','bb','cc',..."(the function uses GROUP_CONCAT). I want to use this as a condition in the IN clase of mysql.
SELECT name,class,comment
FROM vwstudent v
WHERE name IN (select func())
I want the query to act like
SELECT name,class,comment
FROM vwstudent v
WHERE name IN ('aa','bb','cc','dd',..)
I assume ('aa','bb','cc','dd',..) is acting as a whole string here and isn't generating any result. What can I do to run this query error less.
I'm not sure if it'll help. But you might be able to hack something together by using PREPARE and EXECUTE as described here: How To have Dynamic SQL in MySQL Stored Procedure
... but that's completely new to me. I've never used anything like that in MySQL.