OrientDB: Check against LET Variable in WHERE Clause - where-clause

I am trying to write an OrientDB batch script to
extract a DateTime from a specific record (T1)
increase the DateTime by a certain amount (T2)
search for records that have a DateTime between T1 and T2
BEGIN
LET T1 = SELECT time AS value FROM MyClass WHERE id = someID
LET T2 = SELECT sum(first($T1.value).asLong(), someTime).asDateTime() as value
SELECT * FROM MyClass WHERE time > $T1 AND time < $T2
COMMIT
This works fine as long as I don't use $T1 and $T2 (or $T1.value, $T2.value) in the WHERE clause, but strings like "2018-01-01 00:00:00". To better understand the difference between "2018-01-01 00:00:00" and $T1/$T2 (or $T1.value/$T2.value) I added a RETURN $T1/$T2 (or $T1.value/$T2.value) in the end and received the exact same string via studio.
So why can I use a hand-written string in WHERE clause, but not the value of some custom variable?
How would I have to rewrite my script to work as intended?

Related

Snowflake ignores statement in where clause where I'm comparing timestamps

so I'm building a SCD type 2 in snowflake, but it ignores the where clause in which is comparision between "to_timestamp" and "expiry_date". Expiry_date is a variable that is set to '9999-08-17 07:31:29.901000000' (as infinity) and To_timestamp is a column in table. I want to query only the rows that have to_timestamp set to infinity (they are still active) but snowflake seems to ignore this part of where clause. Below is some of the code (it should update the rows that are expired - that means change their "to_timestamp" to current time. and it does but it does to rows with timestamps of all kind - it ignores last line)
SET EXPIRY_DATE_NTZ = '9999-08-17 07:31:29.901000000';
SET CURRENT_DATE_NTZ = TO_TIMESTAMP_NTZ(CURRENT_TIMESTAMP());
UPDATE CUSTOMER_TARGET CT
SET CT.TO_TIMESTAMP = $CURRENT_DATE_NTZ
FROM POC.SNOWFLAKE_POC.CUSTOMER_STAGE CS
WHERE CT.C_CUSTOMER_ID = CS.C_CUSTOMER_ID
AND (CT.C_FIRST_NAME <> CS.C_FIRST_NAME OR CT.C_LAST_NAME <> CS.C_LAST_NAME OR CT.C_BIRTH_YEAR
<> CS.C_BIRTH_YEAR OR CT.C_BIRTH_COUNTRY <> CS.C_BIRTH_COUNTRY OR CT.C_LAST_REVIEW_DATE<>CS.C_LAST_REVIEW_DATE)
AND CT.TO_TIMESTAMP = $EXPIRY_DATE_NTZ;
I have two of these update statements (one for updates and one for deletes) and a merge statement for inserts. And it ignores the comparision in every single one, updating the rows that have "to_timestamp" set to something like "2021-08-24 07:11:53.510000000". I've tried every combination possible (between ... and ..., >= ... <=, <=, >=, comparing in "case" statement of update,...) - nothing. What could be the cause/solution?
As we do not know the structure of CUSTOMER_TARGET I would suggest to explicitly set the data type of EXPIRY_DATE_NTZ variable to match the column data type:
SET EXPIRY_DATE_NTZ = '9999-08-17 07:31:29.901000000';
SELECT $EXPIRY_DATE_NTZ;
DESCRIBE RESULT LAST_QUERY_ID();
to:
-- TIMESTAMP_NTZ as an example
SET EXPIRY_DATE_NTZ = '9999-08-17 07:31:29.901000000'::TIMESTAMP_NTZ;
SELECT $EXPIRY_DATE_NTZ;
DESCRIBE RESULT LAST_QUERY_ID();
By doing that way there are no "implicit conversions" involved in the process.
Another advice is usage of IS DISTINCT FROM instead of <>. IS DISTINCT FROM is NULL safe, which is important if columns are defined as nullable.
UPDATE CUSTOMER_TARGET CT
SET CT.TO_TIMESTAMP = $CURRENT_DATE_NTZ
FROM POC.SNOWFLAKE_POC.CUSTOMER_STAGE CS
WHERE CT.C_CUSTOMER_ID = CS.C_CUSTOMER_ID
AND (CT.C_FIRST_NAME IS DISTINCT FROM CS.C_FIRST_NAME
OR CT.C_LAST_NAME IS DISTINCT FROM CS.C_LAST_NAME
OR CT.C_BIRTH_YEAR IS DISTINCT FROM CS.C_BIRTH_YEAR
OR CT.C_BIRTH_COUNTRY IS DISTINCT FROM CS.C_BIRTH_COUNTRY
OR CT.C_LAST_REVIEW_DATE IS DISTINCT FROM CS.C_LAST_REVIEW_DATE)
AND CT.TO_TIMESTAMP = $EXPIRY_DATE_NTZ;
Your SQL does not have any issues with the filters (ORs are surrounded by the brackets etc). I assume that you have checked the execution profile, and did not see your filter (CT.TO_TIMESTAMP = '9999-08-17 07:31:29.901000000'). In this case, all rows in the target table should have this value in the column TO_TIMESTAMP.
I highly recommend you check the data first. If you are running multiple UPDATE/MERGE commands, you may miss that the data has already updated with this value.

Using parameters in a SSRS Query

Using SQL Server Report Builder with Visual Studio 2012, I'm trying to do a simple query with a #myDate variable in it something like (there might be error in it but I just wrote it up real quick, real query does not have error :D )
Select * from myTable x
inner join OtherTable y on x.Id = y.Id
where x.date = #myDate or y.date = #myDate
So when I use this, I need to create the parameter for it set the name and the value of the parameter, so it would be #myDate and his value would be equal to
=Parameters!myDate.Value.
I want it to be visible so I can change it at any time to query different date which will sort different data from my table.
So I could set a default value but that's not the problem.
The problem I am encountering is when I run the report, it ask me the date I want to set as parameter. I enter a date and then it crashes.
Here's what the error says :
SQL0206 : The column or the global variable #MYDATE is unfindable. Cause...:#MYDATE was not found as a column of the table *N in *N and was not found as a global variable...etc
So after this error I tried to add
DECLARE #myDate as DATE
But that didn't work either..
So do any of you ever did something like this? Should I try something different?
Thanks for taking the time to help a newbie!
---------------Edit---------------
Code for type mismatch
Select * from myTable x
inner join OtherTable y on x.Id = y.Id
where Date(x.date) = ? or Date(y.date) = ?
So when you create a query like this in a SSRS dataset, it will prompt you to identify the parameters. So I had created 1 parameter of type Date/Time (only type of date available in SSRS) and in the query properties I set both ? to value : [#DateParameter]
So the problem now is the data overflow when comparing the SSRS Date/Time type to database Date type
I've found one way to it. You have to use an expression for the query.
so
="Select * from myTable x
inner join OtherTable y on x.Id = y.Id
where Date(x.date) = &" Parameters!MyDate.Value " &
or Date(y.date) = & " Parameters!MyDate.Value " &"
That's my query. Now I had to give a value to my Parameter, so I created another dataset which had this query in it :
SELECT CURRENT TIMESTAMP
FROM sysibm.sysdummy1
And then with this I had a time, I only needed to format it to my need so I added a column with an expression like this :
=Cdate(Left(Cdate(DateSerial(cdate(Left(Fields!Date_Filter.Value,10)).Year,
cdate(Left(Fields!Date_Filter.Value,10)).Month,
cdate(Left(Fields!Date_Filter.Value, 10)).Day)), 10))
And then I set my parameter's default value to this dataset's column. And then it worked just fine!
Try to declare it as a global variable as ##myDate

SQL regex and field

I want to change the query to return multiply values in extra_fields, how can I change the regex? Also I don't understand what extra_fields is - is it a field? If so why it is not called with the table prefix like i.extra_fields?
SELECT i.*,
CASE WHEN i.modified = 0 THEN i.created ELSE i.modified END AS lastChanged,
c.name AS categoryname,
c.id AS categoryid,
c.alias AS categoryalias,
c.params AS categoryparams
FROM #__k2_items AS i
LEFT JOIN #__k2_categories AS c ON c.id = i.catid
WHERE i.published = 1
AND i.access IN(1,1)
AND i.trash = 0
AND c.published = 1
AND c.access IN(1,1)
AND c.trash = 0
AND (i.publish_up = '0000-00-00 00:00:00'
OR i.publish_up <= '2013-06-12 22:45:19'
)
AND (i.publish_down = '0000-00-00 00:00:00'
OR i.publish_down >= '2013-06-12 22:45:19'
)
AND extra_fields REGEXP BINARY '(.*{"id":"2","value":\["[^\"]*1[^\"]*","[^\"]*2[^\"]*","[^\"]*3[^\"]*"\]}.*)'
ORDER BY i.id DESC
The extra_fields is a column of the #__k2_items table. The table qualifier can be omitted, because it is not ambiguous in this query. The column is JSON encoded. That is a serialization format used to store information which is not searchable by design. Applying a RegExp may work one day, but fail another day, since there is no guarantee for id preceeding value (as in your example).
The right way
The right way to filter this is to ignore the extra_fields condition in the SQL query an evaluate in the resultset instead. Example:
$rows = $db->loadObjectList('id');
foreach ($rows as $id => $row) {
$extra_fields = json_decode($row->extra_fields);
if ($extra_fields->id != 2) {
unset($rows[$id]);
}
}
The short way
If you can't change the database layout (which is true for extensions you want to keep updateable), you must split the condition into two, because there is no guarantee for a certain order of the subfields. For some reason, one day value may occur before id. So change your query to
...
AND extra_fields LIKE '%"id":"2"%'
AND extra_fields REGEXP BINARY '"value":\[("[^\"]*[123][^\"]*",?)+\]'
Prepare an intermediate table to hold the contents of extra_fields. Each extra_fields field will be converted into a series of records. Then do a join.
Create a trigger and cronjob to keep the temp table in sync.
Another way is to write UDF in Perl that will decode the field, but AFAIK it is not indexable in mysql.
Using an external search engine is out of scope.
Ok, i didnt want to change the db strucure, i gost some help and changed the regex intoAND extra_fields REGEXP BINARY '(.*{"id":"2","value":\[("[^\"]*[123][^\"]*",?)+\]}.*)'
and i got the right resaults
Thanks

Getting table(records) to update properply using the MERGE Statement

Good morning everyone!
Below is a piece of code I stitched together: I used a CTE to grab the records(data) from a link table and than convert strings to dates, than use the merge statement to get the data into a local table:
I am having a problem with the column(field) LAST_RACE_DATE this field is set to NULL and is not required but it does not update with my current set up. What I am trying to accomplished is for this field to populate when data is entered but also update, meaning it should also update with NULL.
So if the field has a specific date, and a new date is entered in the remote database, this field should update as well, even if the data is deleted in the back end, it should also remove the local table data for this field.
WITH CTE AS(
SELECT MEMBER_ID
,[MEMBER_DATE] = MAX(CONVERT(DATE, MEMBER_DATE))
,RACE_DATE = MAX(CONVERT(DATE, RACE_DATE))
,LAST_RACE_DATE = MAX(CONVERT(DATE, LAST_RACE_DATE))
FROM [EXAMPLE].[dbo].[LINKED_MEMBER_DATA]
WHERE (MEMBER_DATE IS NOT NULL) AND (ISDATE(MEMBER_DATE)<> 0) AND (RACE_DATE IS NOT NULL) AND (ISDATE(RACE_DATE)<> 0)
AND (LAST_RACE_DATE IS NULL) OR (ISDATE(LAST_RACE_DATE)<> 0)
GROUP BY MEMBER_ID)
MERGE dbo.LINKED_MEMBER_DATA AS Target
USING (SELECT
MEMBER_ID, MEMBER_DATE, RACE_DATE, LAST_RACE_DATE
FROM CTE
GROUP BY MEMBER_ID, RACE_DATE, LAST_RACE_DATE)AS SOURCE ON (Target.MEMBER_ID = SOURCE.MEMBER_ID)
WHEN MATCHED AND
(Target.MEMBER_DATE) <> (SOURCE.MEMBER_DATE)
OR (Target.RACE_DATE) <> (SOURCE.RACE_DATE)
OR ISNULL(TARGET.LAST_RACE_DATE , Target.LAST_RACE_DATE) <> ISNULL(SOURCE.LAST_RACE_DATE, SOURCE.LAST_RACE_DATE)
THEN UPDATE SET
Target.MEMBER_DATE = SOURCE.MEMBER_DATE
,Target.RACE_DATE = SOURCE.RACE_DATE
,Target.LAST_RACE_DATE = SOURCE.LAST_RACE_DATE
WHEN NOT MATCHED BY TARGET THEN
INSERT(
MEMBER_ID, MEMBER_DATE, RACE_DATE, LAST_RACE_DATE)
VALUES (Source.MEMBER_ID, Source.MEMBER_DATE, Source.RACE_DATE, Source.LAST_RACE_DATE);
I also tried this:
ISNULL(Target.LAST_RACE_DATE,'N/A') <> ISNULL(SOURCE.LAST_RACE_DATE,'N/A')
But it generates the below error for dates conversion:
Conversion failed when converting date and/or time from character string.
Thanks a Million!!
Your current statement is failing because the ISNULLs that you have don't do anything (if one of the values is NULL the expression will evaluate to NULL), and NULL values don't compare. Your second attempt doesn't work because ISNULL requires the data types of the two values to be the same, so you could try eg ISNULL(Target.LAST_RACE_DATE, '1970-01-01') <> ISNULL(Source.LAST_RACE_DATE, '1970-01-01').
Another option would be to simply enumerate the different cases (eg, (((Source.LAST_RACE_DATE IS NULL AND Target.LAST_RACE_DATE IS NOT NULL) OR (Source.LAST_RACE_DATE IS NOT NULL AND Target.LAST_RACE_DATE IS NULL) OR (Source.LAST_RACE_DATE <> Target.LAST_RACE_DATE))). Enumerating the different situations makes the code a bit more verbose, but it can result in better performance (whether it is measurably better really depends on how much data you are processing).

SQL - WHERE clause on each SET command in UPDATE?

I'm trying to create an SQL query in PHP to update a table.
Is it possible to have a different WHERE clause for each affected row?
eg something like:
UPDATE table
SET val=X WHERE someproperty = 1,
SET val=Y WHERE someproperty = 2
etc?
Any help appreciated. Thanks
Yes, you can with a CASE statement.
UPDATE table
SET val = CASE someproperty
WHEN 1 THEN x
WHEN 2 THEN y
....
ELSE
val
END
Now, there is concern that one CASE statement is less readable when compared to several UPDATE statements. There is a valid argument here. For example, when 1000 rows are being updated, it just feels and looks better to use several UPDATE statements rather than 1000 different conditions to a single CASE.
However, sometimes a CASE statement is more appropriate. If, for example, you are updating rows based on some trait, say the even or odd nature of a field's value the table, then a CASE statement is a wonderfully concise and maintainable way to update rows in the table without having to resort to a huge number of UPDATE statements that all share a specific type of logic. Take this for example:
UPDATE table
SET val = CASE MOD(someproperty, 2)
WHEN 0 THEN x
WHEN 1 THEN y
END
This expression takes the modulus of someproperty and, when 0 (even), assigns value x to val and, when 1 (odd), assigns value y to val. The greater the volume of data being updated by this statement, the cleaner it is compared to doing so by multiple UPDATE statements.
In short, CASE statements are sometimes just as readable/maintainable as UPDATE statements. It all depends on what you are trying to do with them.
EDIT: Added the ELSE clause to be extra safe. The OP may be interested in updating only specific rows so the rest should remain as they prior to the UPDATE.
EDIT: Added a scenario where the CASE statement is a more effective approach than multiple UPDATE statements.
You cannot have multiple WHERE clauses for any SQL statement, however you can use a CASE statement to accomplish what you are trying to do. Another option that you have is to execute multiple UPDATE statements.
Here is a sample using the CASE statement:
UPDATE table
SET val = (
CASE someproperty
WHEN 1 THEN X
WHEN 2 THEN Y
ELSE val
END
);
Here is a sample using multiple UPDATE statements:
UPDATE table SET val=X WHERE someproperty = 1;
UPDATE table SET val=Y WHERE someproperty = 2;
Nope. Make it two updates:
UPDATE table SET val=X WHERE someproperty = 1;
UPDATE table SET val=Y WHERE someproperty = 2;
On second thought, you could use sub-queries or the case statement...
UPDATE table SET val= ( case when someproperty = 1 then X when someproperty = 2 then Y else val END )
You may need to make that a sub query like this:
UPDATE table t1 SET val = ( select CASE when someproperty = 1 then X when someproperty = 2 then Y ELSE val END from table t2 where t1.primarykey = t2.primary key )
UPDATE TABLE
SET VAL CASE SOMEPROPERTY WHEN 1 THEN X WHEN 2 THEN Y END
A compact and easily scaleable way:
UPDATE table1 SET val=ELT(FIND_IN_SET(someproperty, '1, 2'), X, Y);
make the query this way:
$condition = array(1, 2);
$newvals = array('X', 'Y');
$query = "UPDATE table1 SET val=ELT(FIND_IN_SET(someproperty, '". implode(',', $condition). "', ". implode(', ', $newvals). ")";
Use prepare_query to avoid SQL syntax errors if you deal with string values.