Take a look at the following query. How do you display Column 'Action' as text.
If the result of 'Action' is LEQ 0 then dipslay the text "Crash" and if 'Action'
is GRT 0 display the text "Hold"?
SELECT col1 AS Action
FROM vdk
WHERE t_stamp Between "{StartTime}" AND "{EndTime}"
Refactoring the answer above, since i don't see the necessity to add a query to an alias table. I think this should work the other answer should work too btw, but its a little more complicated query for no given reason.
SELECT (CASE WHEN col1 <= 0 THEN 'Crash' ELSE 'Hold' END) AS Action
FROM vdk
WHERE t_stamp Between "{StartTime}" AND "{EndTime}"
Use CASE WHEN ... ELSE ... END and select from your set (query):
SELECT *, (CASE WHEN Action <= 0 THEN 'Crash' ELSE 'Hold' END) as ActionText
FROM (
SELECT col1 AS Action
FROM vdk
WHERE t_stamp Between "{StartTime}" AND "{EndTime}"
) q
This application is similar to my first question and I thought it might help someone else down the the road.
User can select from a Table's Drop Down List a set of options to enter a value into the Database.
Using Ignition's Power Table Component's Extension Function configureEditor with the following script.
This script sets up the Drop Down List.
if colName == 'Action':
return {options': [(0, 'Null'), (1, 'HOLD'), (2, 'CRASH')]}
Along with the same Power Table's Extension Function onCellEdited script.
This script enters the selection as a value into the database.
#onCellEdited Upadte Query
row = rowIndex
col = colIndex
colName = colName
value = newValue
ndx = self.data.getValueAt(row,0)
query = "UPDATE vdk SET %s = ? WHERE ndx = ?" % colName
system.db.runPrepUpdate(query,[value,ndx],'history')
system.db.refresh(self.data)
Related
I would like to do the following.
Update a field based on the value of another field like
update table set if(fielda=1){fieldb=2 fieldc=3}else{fieldd=2 fielde=3}
I know this is not valid mysql but its the best way for me to describe the problem.
update table set
b = case when a = 1 then 2 else b end,
c = case when a = 1 then 3 else c end,
d = case when a = 1 then d else 2 end,
e = case when a = 1 then e else 3 end
edit
according to your comment try this:
update table set
datefield_a = case when field_a = 1 then now() else datefield_a end,
datefield_b = case when field_a <> 1 then now() else datefield_b end
I think this syntax will achieve the result you attempted to specify.
UPDATE mytable
SET fieldb = CASE WHEN fielda = 1 THEN 2 ELSE fieldb END
, fieldc = CASE WHEN fielda = 1 THEN 3 ELSE fieldc END
, fieldd = CASE WHEN fielda = 1 THEN fieldd ELSE 2 END
, fielde = CASE WHEN fielda = 1 THEN fielde ELSE 3 END
The "trick" here is that we are updating all four columns, but in some "cases", we are assigning the current value of the column back to the column, resulting in no real change to the column value. (Once you get your mind bent around that idea, it's pretty easy.)
With MySQL, we do have a handy IF function (not available in most other RDBMS) that we can use to abbreviate that a bit, and achieve the same thing:
UPDATE mytable
SET fieldb = IF(fielda = 1, 2, fieldb)
, fieldc = IF(fielda = 1, 3, fieldc)
, fieldd = IF(fielda = 1, fieldd, 2)
, fielde = IF(fielda = 1, fielde, 3)
The pain is that you still have to repeat that same conditional test multiple times.
A single scan through the table (like these statements do), and getting all those assignments done in one fell swoop is going to be faster (and more efficient) than breaking this up and doing the assignments piecemeal using multiple statements.
Hello I have this query that i am trying to execute and i keep getting this error "Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.", Kindly help please.
DECLARE #NUMCOUNT BIT
Select #NUMCOUNT = (SELECT
CASE WHEN
(SELECT COUNT(R5REQUISLINES.RQL_REQ)
WHERE R5REQUISLINES.RQL_STATUS IN ('A')
) IN
(SELECT COUNT(R5REQUISLINES.RQL_REQ)
WHERE R5REQUISLINES.RQL_STATUS IN ( 'A','C') ) THEN 1 else 0 END AS NUMCOUNT1
FROM R5REQUISLINES JOIN
R5REQUISITIONS ON R5REQUISLINES.RQL_REQ = R5REQUISITIONS.REQ_CODE
GROUP BY R5REQUISLINES.RQL_REQ, R5REQUISITIONS.REQ_CODE,R5REQUISLINES.RQL_STATUS
)
IF #NUMCOUNT = '1'
begin
UPDATE R5REQUISITIONS
SET R5REQUISITIONS.REQ_STATUS = 'CP'
end
Ok, it sounds like what you actually want to do is update R5REQUISITIONS when there is no RQL_STATUS = 'C' in R5REQUISLINES, since you said you want to count the records where the RQL_STATUS is A and where it's A or C, and then do the update if the counts are the same.. You can greatly simplify this task with the following query:
UPDATE r5
SET r5.REQ_STATUS = 'CP'
FROM R5REQUISITIONS r5
WHERE NOT EXISTS (SELECT 1 FROM R5REQUISLINES r5q WHERE r5q.RQL_REQ = r5.REQ_CODE AND r5q.RQL_STATUS = 'C')
Your 'SELECT CASE' is returning more than 1 record, so it can't be assigned to #NUMBER. Either fix the sub-query to only return the record your looking for or hack it to return only 1 with a 'LIMIT 1' qualification.
I don't know what your data looks like so I can't tell you why your case subquery returns more records than you think it should.
Try running this and see what it returns, that will probably tell you wall you need to know:
SELECT
CASE WHEN
(SELECT COUNT(R5REQUISLINES.RQL_REQ)
WHERE R5REQUISLINES.RQL_STATUS IN ('A')
) IN
(SELECT COUNT(R5REQUISLINES.RQL_REQ)
WHERE R5REQUISLINES.RQL_STATUS IN ( 'A','C')
)
THEN 1
ELSE 0
END AS NUMCOUNT1
FROM R5REQUISLINES JOIN
R5REQUISITIONS ON R5REQUISLINES.RQL_REQ = R5REQUISITIONS.REQ_CODE
GROUP BY R5REQUISLINES.RQL_REQ, R5REQUISITIONS.REQ_CODE,R5REQUISLINES.RQL_STATUS
If there is more than 1 row returned, that's where your problem is.
I would like to use if statement in sql query :
what I want :
if(tractions_delivery.send_date_id !=0 ){
date_send_commodities.id = tractions_delivery.send_date_id
}
my query :
from
tractions_delivery,user_address,province,city,date_send_commodities,users
WHERE
tractions_delivery.tr_id = $tr_id
AND
tractions_delivery.address_id = user_address.id
AND
user_address.province_id = province.id
AND
user_address.city_id = city.id
AND
//not work
(tractions_delivery.send_date_id IS NOT 0 date_send_commodities.id = tractions_delivery.send_date_id)
AND
users.id = user_address.user_id
You could use the CASE-statement
SELECT
*
FROM
tractions_delivery,
user_address,
province,
city,
date_send_commodities,users
WHERE
tractions_delivery.tr_id = $tr_id AND
tractions_delivery.address_id = user_address.id AND
user_address.province_id = province.id AND
user_address.city_id = city.id AND
CASE WHEN tractions_delivery.send_date_id != 0 THEN date_send_commodities.id = tractions_delivery.send_date_id ELSE 1=1 END AND
users.id = user_address.user_id
You can only use if statements in stored procedures or functions. If you just write a sql statement unfortunately you cannot use if statements around the query. But you can use logic in the query itself, e.g.:
SELECT CASE WHEN col1 = col2 THEN'col1 equals col2' else 'col1 doesnt equal col2' ELSE
FROM table1
So around doesnt work, but in the field list you can create CASE WHEN ELSE END logic.
CASE or IF() operators can be of help.
Examples,
SELECT (CASE 1 WHEN 1 THEN 'One' WHEN 2 THEN 'Two' ELSE 'More' END) 'Result';
OR
SELECT IF(1=1, 'One', 'Two') 'Result';
These CASE and IF() operators can be used in the SELECT clause to conditionally interpret column values and return in the resultset.
Note: Do not confuse CASE operator here with 'CASE conditional syntax block' that ends with END CASE.
I am trying to display a field value based on the value of field and then find a external table record.
can I do it?
SELECT
CASE
WHEN (dsp_notes IS NOT NULL) THEN '*'
WHEN (dsp_notes IS NULL) THEN ''
ELSE ''
END,
CASE
WHEN (dsp_priority = '1') THEN [SELECT uvi_value FROM PUB.universalinfo WHERE uvi_key = 'DSP01SHORT']
Is this possible?
Yes. This is called a scalar subquery and it needs to return one column and one row:
(CASE WHEN dsp_priority = '1'
THEN (SELECT ui.uvi_value FROM PUB.universalinfo ui WHERE ui.uvi_key = 'DSP01SHORT')
END) as NewCol
I strongly encourage you to use table aliases on your column references.
I'm about to build some sort of function or query where I can check if a certain record already exists in the database. The following rules apply:
The table has 6 columns
My yet-to-build-query has access to a complete row-object (all 6 values)
This query should find each row with at least 4 out of 6 corresponding values from the object I passed
Using MySQL
Is it even possible to build a query like this? My goal is to have a function which can return true if it's likely that a row like the passed object is already existing in the database.
Is my only option to make a query with multiple where-statements (where I try for each combination 4 different values)?
pseudo:
function getSimilarRow(Row_Object $row)
{
//select *
//from table_x
//where 4 out of 6 properties from object $row apply
}
You could use a case statement in the where clause for each property you are trying to match. If it meets the criteria then give the case statement a value of 1; if it doesn't then give it 0. The sum of the cases should then be >= 4.
I'm not that familiar with MySQL but the following will work (I knocked up a quick SQL Fiddle to show it working):
select * from SomeTable where
(case when propertyOne = 'value1' then 1 else 0 end) +
(case when propertyTwo = 'value2' then 1 else 0 end) +
(case when propertyThree = 'value3' then 1 else 0 end) +
(case when propertyFour = 'value4' then 1 else 0 end) +
(case when propertyFive = 'value5' then 1 else 0 end) +
(case when propertySix = 'value6' then 1 else 0 end) >= 4
Obviously you could change your logic in each clause if you'd prefer them to be likes or anything. You could even apply a weighting to each column by using something other than just 1 if you needed to get really creative.