statement 1:
create table tmp as select code , round((max(close)-min(close))/min(close),2) as volatility,
case when (max(close)-min(close))/min(close) <0.1 then "grade1"
when (max(close)-min(close))/min(close) <0.2 then "grade2"
when (max(close)-min(close))/min(close) <0.3 then "grade3"
else "grade4" end as type
from quote where date between '20120801' and '20121101' and code<'07000'
group by code order by volatility ;
statement 2:
select tmp.code,profile.name, tmp.volatility from tmp,profile where tmp.code=profile.code;
the statement 1 and statement 2 can run ,when i combine the two into one --the statement 3,
it can't run ,what is the matter?
statement 3:
select quote.code ,profile.name, round((max(quote.close)-min(quote.close))/min(quote.close),2) as quote.volatility,
case when (max(quote.close)-min(quote.close))/min(quote.close) <0.1 then "grade1"
when (max(quote.close)-min(quote.close))/min(quote.close) <0.2 then "grade2"
when (max(quote.close)-min(quote.close))/min(quote.close) <0.3 then "grade3"
else "grade4" end as quote.type
from quote，profile where quote.date between '20120801' and '20121101' and quote.code<'07000' and quote.code=profile.code
group by quote.code order by quote.volatility ;
Just make your first statement a subquery:
select tmp.code, profile.name, tmp.volatility
from (select code,
round(...) as volatility,
case ... end as type
from quote
where date between '20120801' and '20121101'
and code<'07000'
group by code
order by volatility) as tmp,
profile
where tmp.code = profile.code;
Related
I am working on an sqlite3 shell.
SELECT * FROM tasks WHERE name in ("TaskA", "TaskD") LIMIT 5;
The above statement will print the first 5 rows only. Is there a way to write this statement so the first 5 rows from each of "TaskA" and "TaskD" results are printed?
In essence, I am trying to write a loop akin to:
FOR task in ("TaskA", "TaskD") SELECT * FROM tasks WHERE name = task LIMIT 5;
But I do not know the proper syntax.
Use ROW_NUMBER() window function:
SELECT *
FROM (
SELECT *, ROW_NUMBER() OVER (PARTITION BY name ORDER BY rowid) rn
FROM tasks
WHERE name IN ("TaskA", "TaskD")
)
WHERE rn <= 5
I used the column rowid to define the order of the rows.
If there is another column in your table, like a date column, that can be used to define the order, you can replace rowid with that column.
Thanks again for the help everyone. I went with the script below...
SELECT beginning, end,
(SELECT SUM(sale) FROM sales_log WHERE date BETWEEN beginning AND `end` ) AS sales
FROM performance
and I added a salesperson column to both the performance table and sales_log but it winds up crashing DB Browser. What is the issue here? New code below:
SELECT beginning, end, salesperson
(SELECT SUM(sale) FROM sales_log WHERE (date BETWEEN beginning AND end) AND sales_log.salesperson = performance.salesperson ) AS sales
FROM performance
I believe that the following may do what you wish or be the basis for what you wish.
WITH sales_log_cte AS
(
SELECT substr(date,(length(date) -3),4)||'-'||
CASE WHEN length(replace(substr(date,instr(date,'/')+1,2),'/','')) < 2 THEN '0' ELSE '' END
||replace(substr(date,instr(date,'/')+1,2),'/','')||'-'||
CASE WHEN length(substr(date,1,instr(date,'/') -1)) < 2 THEN '0' ELSE '' END||substr(date,1,instr(date,'/') -1) AS date,
CAST(sale AS REAL) AS sale
FROM sales_log
),
performance_cte AS
(
SELECT substr(beginning,(length(beginning) -3),4)||'-'||
CASE WHEN length(replace(substr(beginning,instr(beginning,'/')+1,2),'/','')) < 2 THEN '0' ELSE '' END
||replace(substr(beginning,instr(beginning,'/')+1,2),'/','')||'-'||
CASE WHEN length(substr(beginning,1,instr(beginning,'/') -1)) < 2 THEN '0' ELSE '' END||substr(beginning,1,instr(beginning,'/') -1)
AS beginning,
substr(`end`,(length(`end`) -3),4)||'-'||
CASE WHEN length(replace(substr(`end`,instr(`end`,'/')+1,2),'/','')) < 2 THEN '0' ELSE '' END
||replace(substr(`end`,instr(`end`,'/')+1,2),'/','')||'-'||
CASE WHEN length(substr(`end`,1,instr(`end`,'/') -1)) < 2 THEN '0' ELSE '' END||substr(`end`,1,instr(`end`,'/') -1)
AS `end`
FROM performance
)
SELECT beginning, `end` , (SELECT SUM(sale) FROM sales_log_cte WHERE date BETWEEN beginning AND `end` ) AS sales
FROM performance_cte
;
From your data this results in :-
As can be seen the bulk of the code is converting the dates into a format (i.e. YYYY-MM-DD) that is usable/recognisable by SQLite for the BETWEEN clause.
Date And Time Functions
I don't believe that you want a join between performance (preformance_cte after reformatting the dates) and sales_log (sales_log_cte) as this will be a cartesian product and then sum will sum all the results within the range.
The use of end as a column name is also awkward as it is a KEYWORD requiring it to be enclosed (` grave accents used in the above).
The above works by using 2 CTE's (Common Table Expresssions), which are temporary tables who'd life time is for the query in which they are used.
The first sales_log_cte is simply the sales_log table but with the date reformatted. The second, likewise, is simply the performace table with the dates reformatted.
If the tables already has suitable date formatting then all of the above could simply be :-
SELECT beginning, `end` , (SELECT SUM(sale) FROM sales_log WHERE date BETWEEN beginning AND `end` ) AS sales FROM performance;
My question is about using case statement in where clause to check for date and assign values to columns. My sample code include.
select * from table
where
column 1 > 10 and
case when column 2 = 1
then
column 3<= 10 and column 4 between (1st day of prev month) and (prev month end) or column 5 = '8888-01-01'
else
column 4 between (1st day of this month) and (yesterday)
end ;
when I am running this code. I am getting 3706 syntax error:expected something in between field and '='.
How to fix this ?
A CASE statement will always return a value or NULL (if none of the conditions matches), so you can use it in your WHERE clause. There are a couple ways to format your CASE statement:
Format 1
CASE
WHEN <condition> THEN <some_expression>
WHEN <another_condition> THEN <another_expression>
ELSE <final_expression>
END
-- Example
CASE
WHEN col1 = 10 THEN 'Y'
WHEN col1 = 20 THEN 'N'
ELSE 'N/A'
END
Format 2
CASE <expression>
WHEN <value> THEN <expression>
WHEN <another_value> THEN <another_expression>
ELSE <final_expression>
END
-- Example
CASE col1
WHEN 10 THEN 'Y'
WHEN 20 THEN 'N'
ELSE 'NA'
END
I'm not sure what you're trying to do with your sample code, but it looks more like pseudo-code and will not work as-is. Your CASE statement is not formatted properly and your column references like column 1 will not work that way. If your column is actually named column 1, then you need to put double-quotes around it:
select * from table where "column 1" > 10
Can you please describe a little more clearly what exactly you are trying to do?
A CASE expression can't be used to create some kind of dynamic conditions. Write it as a bunch of AND/OR conditons:
select * from table
where
column 1 > 10 and
(
( column 2 = 1 and
(column 3<= 10 and column 4 between (1st day of prev month) and (prev month end) or column 5 = '8888-01-01')
)
or
column 4 between (1st day of this month) and (yesterday)
);
Double check the logic, the precedence of logical operators is
parenthesis
NOT
AND
OR
I am using the following insert query to create a comparison between two tables using the dates to join on.
INSERT INTO Comp_Table (Date, CKROne, CKRTwo, ChangeOne, ChangeTwo, State)
SELECT BaseTbl.Date, BaseTbl.CKR, CompTbl.CKR, BaseTbl.Change, CompTbl.Change,
CASE
WHEN BaseTbl.Change > 0 AND CompTbl.Change > 0 THEN 'positive'
WHEN BaseTbl.Change < 0 AND CompTbl.Change < 0 THEN 'positive'
ELSE 'inversely'
END AS 'Correlation'
FROM BaseTbl
JOIN CompTbl ON BaseTbl.Date = CompTbl.Date;
This works well. However, I would like to be able to join the tables with a lag. As in, the user can define if they want to do exact match on dates or if they want to use a date of one's occurrence plus a number and return the value from the latter date for comparison to the number to the former date. Pseudo code example:
User sets variable = 0 then
Join ComTbl On BaseTbl.Date = CompTbl.Date + 0;
User sets variable = 7 then
Join CompTbl On BaseTbl.Date = CompTbl.Date + 7;
(joins 2012-01-01 from BaseTbl to 2012-01-08 from CompTbl)
I tried to add days like you would in a Where clause ('+7 day'), but this didn't work. I also tried to using a Where clause with BaseTbl.Date = CompTbl.Date '+ 7 day' but that returned a 0 value also. How can this be accomplished in SQLite?
I think you can use the DATE() function to build the WHERE clause you want:
INSERT INTO ...
SELECT ...
FROM BaseTbl
INNER JOIN ComTbl
ON BaseTbl.Date = DATE(CompTbl.Date, '7 days')
I've just started learning SQLite, and had a question.
Here is an example of what I mean.
This is my CSV:
date
2010-10-24
2010-10-31
2010-11-01
2011-02-14
2011-02-15
2011-02-16
2011-10-01
2012-01-15
2012-05-12
2012-05-14
2012-08-12
2012-08-26
My code:
SELECT STRFTIME('%Y-%m', date) AS 'month', COUNT() AS 'month_count'
FROM tableName
GROUP BY STRFTIME('%Y-%m', date);
The result (in comma-delimited form):
month, month_count
2010-10, 2
2010-11, 1
2011-02, 3
2011-10, 1
2012-01, 1
2012-05, 2
2012-08, 2
What I'm looking for now, is a way to get the average number of 'month_count' per month, which is of course different from just the average of 'month_count'. That is, the former equals 0.55, while the latter equals 1.71, and I'm trying ti calculate the former.
I tried using AVG(COUNT()), though that obviously made no logical sense.
I'm guessing I'd have to store the code-generated table as a temporary file, then get the average from it, though I'm not sure how to properly write it.
Does anyone know what I'm missing?
Try the code below:
create table test(date date);
insert into test values ('2010-10-24');
insert into test values ('2010-10-31');
insert into test values ('2010-11-01');
insert into test values ('2011-02-14');
insert into test values ('2011-02-15');
insert into test values ('2011-02-16');
insert into test values ('2011-10-01');
insert into test values ('2012-01-15');
insert into test values ('2012-05-12');
insert into test values ('2012-05-14');
insert into test values ('2012-08-12');
insert into test values ('2012-08-26');
SELECT a.tot_months
, b.month_diff
, cast(a.tot_months as float) / b.month_diff avg_count
FROM (SELECT COUNT(*) tot_months FROM test) a
, (SELECT cast((strftime('%m',max(date))+12*strftime('%Y',max(date))) as int) -
cast((strftime('%m',min(date))+12*strftime('%Y',min(date))) as int) as 'month_diff'
FROM test) b
;
Output:
C:\scripts>sqlite3 < foo.sql
12|22|0.545454545454545