I am currently building a dynamic SQL query. The tables and columns are sent as parameters. So the columns may not be present in the table. Is there a way to pull NULL data in the result set when the column is not present in the table?
ex:
SELECT * FROM Table1
Output:
created date | Name | Salary | Married
-------------+-------+--------+----------
25-Jan-2016 | Chris | 2500 | Y
27-Jan-2016 | John | 4576 | N
30-Jan-2016 | June | 3401 | N
So when I run the query below
SELECT Created_date, Name, Age, Married
FROM Table1
I need to get
created date | Name | AGE | Married
-------------+-------+--------+----------
25-Jan-2016 | Chris | NULL | Y
27-Jan-2016 | John | NULL | N
30-Jan-2016 | June | NULL | N
Does anything like IF NOT EXISTS or ISNULL work in this?
I can't use extensive T-SQL in this segment and need to be simple since I am creating a UNION query to more than 50 tables (requirement :| ) . Any advice would be of great help to me.
I can't think of an easy solution. Since you're using dynamic sql, instead of
(previous dynamic string part)+' fieldname '+(next dynamic string part)
you could use
(previous dynamic string part)
+ case when exists (
select 1
from sys.tables t
inner join sys.columns c on t.object_id=c.object_id
where c.name=your_field_name and t.name=your_table_name)
) then ' fieldname ' else ' NULL ' end
+(next dynamic string part)
Related
I have an information table with a column of an array in string format. The length is unknown starting from 0. How can I put it in a where clause of PostgreSQL?
* hospital_information_table
| ID | main_name | alternative_name |
| --- | ---------- | ----------------- |
| 111 | 'abc' | 'abe, abx' |
| 222 | 'bbc' | '' |
| 333 | 'cbc' | 'cbe,cbd,cbf,cbg' |
* record
| ID | name | hospital_id |
| --- | ------- | ------------ |
| 1 | 'abc-1' | |
| 2 | 'bbe+2' | |
| 3 | 'cbf*3' | |
e.g. this column is for alternative names of hospitals. let's say e.g. 'abc,abd,abe,abf' as column Name and '111' as ID. And I have a record with a hospital name 'cbf*3' ('3' is the department name) and I would like to check its ID. How can I check all names one by one in 'cbe,cbd,cbf,cbg' and get its ID '333'?
--update--
In the example, in the record table, I used '-', '*', '+', meaning that I couldn't split the name in the record table under a certain pattern. But I can make sure that some of the alternative names may appear in the record name (as a substring). something similar to e.g. 'cbf' in 'cbf*3'. I would like to check all names, if 'abe' in 'cbf*3'? no, if 'abx' in 'cbf*3'? no, then the next row etc.
--update--
Thanks for the answers! They are great!
For more details, the original dataset is not in alphabetic languages. The text in the record name is not separable. it is really hard to find a separator or many separators. Therefore, for the solutions with regrex like '[-*+]' could not work here.
Thanks in advance!
You could use regexp_split_to_array to convert the coma-delimited string to a proper array, and then use the any operator to search inside it:
SELECT r.*, h.id
FROM record r
JOIN hospital_information h ON
SPLIT_PART(r.name, '-', 1) = ANY(REGEXP_SPLIT_TO_ARRAY(h.name, ','))
SQLFiddle demo
Substring can be used with a regular expression to get the hospital name from the record's name.
And String_to_array can transform a CSV string to an array.
SELECT
r.id as record_id
, r.name as record_name
, h.id as hospital_id
FROM record r
LEFT JOIN hospital_information h
ON SUBSTRING(r.name from '^(.*)[+*\-]\w+$') = ANY(STRING_TO_ARRAY(h.alternative_name,',')||h.main_name)
WHERE r.hospital_id IS NULL;
record_id
record_name
hospital_id
1
abc-1
111
2
bbe+2
222
3
cbf*3
333
Demo on db<>fiddle here
Btw, text [] can be used as a datatype in a table.
Suppose that I have a table named agents_timesheet that having a structure like this:
ID | name | health_check_record | date | clock_in | clock_out
---------------------------------------------------------------------------------------------------------
1 | AAA | {"mental":{"stress":"no", "depression":"no"}, | 6-Dec-2021 | 08:25:07 |
| | "physical":{"other_symptoms":"headache", "flu":"no"}} | | |
---------------------------------------------------------------------------------------------------------
2 | BBB | {"mental":{"stress":"no", "depression":"no"}, | 6-Dec-2021 | 08:26:12 |
| | "physical":{"other_symptoms":"no", "flu":"yes"}} | | |
---------------------------------------------------------------------------------------------------------
3 | CCC | {"mental":{"stress":"no", "depression":"severe"}, | 6-Dec-2021 | 08:27:12 |
| | "physical":{"other_symptoms":"cancer", "flu":"yes"}} | | |
Now I need to get all agents having flu at the day. As for getting the flu from a single JSON in Oracle SQL, I can already get it by this SQL statement:
SELECT * FROM JSON_TABLE(
'{"mental":{"stress":"no", "depression":"no"}, "physical":{"fever":"no", "flu":"yes"}}', '$'
COLUMNS (fever VARCHAR(2) PATH '$.physical.flu')
);
As for getting the values from the column health_check_record, I can get it by utilizing the SELECT statement.
But How to get the values of flu in the JSON in the health_check_record of that table?
Additional question
Based on the table, how can I retrieve full list of other_symptoms, then it will get me this kind of output:
ID | name | other_symptoms
-------------------------------
1 | AAA | headache
2 | BBB | no
3 | CCC | cancer
You can use JSON_EXISTS() function.
SELECT *
FROM agents_timesheet
WHERE JSON_EXISTS(health_check_record, '$.physical.flu == "yes"');
There is also "plain old way" without JSON parsing only treting column like a standard VARCHAR one. This way will not work in 100% of cases, but if you have the data in the same way like you described it might be sufficient.
SELECT *
FROM agents_timesheet
WHERE health_check_record LIKE '%"flu":"yes"%';
How to get the values of flu in the JSON in the health_check_record of that table?
From Oracle 12, to get the values you can use JSON_TABLE with a correlated CROSS JOIN to the table:
SELECT a.id,
a.name,
j.*,
a."DATE",
a.clock_in,
a.clock_out
FROM agents_timesheet a
CROSS JOIN JSON_TABLE(
a.health_check_record,
'$'
COLUMNS (
mental_stress VARCHAR2(3) PATH '$.mental.stress',
mental_depression VARCHAR2(3) PATH '$.mental.depression',
physical_fever VARCHAR2(3) PATH '$.physical.fever',
physical_flu VARCHAR2(3) PATH '$.physical.flu'
)
) j
WHERE physical_flu = 'yes';
db<>fiddle here
You can use "dot notation" to access data from a JSON column. Like this:
select "DATE", id, name
from agents_timesheet t
where t.health_check_record.physical.flu = 'yes'
;
DATE ID NAME
----------- --- ----
06-DEC-2021 2 BBB
Note that this approach requires that you use an alias for the table name (so you can use it in accessing the JSON data).
For testing I used the data posted by MT0 on dbfiddle. I am not a big fan of double-quoted column names; use something else for "DATE", such as dt or date_.
I have a table with column GetDup and I'd like to the duplicate records based on the value of this column. For example, if value on is 1 in GetDup, then duplicate the record once. If value in the column is 2, then duplicate the record twice and so on and the statement has to be in looping statement.
What will be a good way to write a stored procedures for this? Please help.
Input:
+--------+--------------+---------------+
| Getdup | CustomerName | CustomerAdd |
+--------+--------------+---------------+
| 1 | John | 123 SomeWhere |
| 2 | Bob | 987 SomeWhere |
+--------+--------------+---------------+
What I want:
+--------+--------------+---------------+
| Getdup | CustomerName | CustomerAdd |
+--------+--------------+---------------+
| 1 | John | 123 SomeWhere |
| 1 | John | 123 SomeWhere |
| 2 | Bob | 987 SomeWhere |
| 2 | Bob | 987 SomeWhere |
| 2 | Bob | 987 SomeWhere |
+--------+--------------+---------------+
picture of data
Answer #2 After Clarification
Number Table to the Rescue!
The number table in my example (or tally table, if you want to call it that), is both temporary and very small. To make it bigger, just add more values to z and add more CROSS JOINs. In my opinion, a number table and a calendar table are both things that should be in every database you have. They are extremely useful.
SQL Fiddle
MS SQL Server 2017 Schema Setup:
CREATE TABLE mytable ( Getdup int, CustomerName varchar(10), CustomerAdd varchar(20) ) ;
INSERT INTO mytable (Getdup, CustomerName, CustomerAdd)
VALUES (1,'John','123 SomeWhere'), (2,'Bob','987 SomeWhere')
;
Query 1:
;WITH z AS (
SELECT *
FROM ( VALUES(0),(0),(0),(0) ) v(x)
)
, numTable AS (
SELECT num
FROM (
SELECT ROW_NUMBER() OVER (ORDER BY z1.x)-1 num
FROM z z1
CROSS JOIN z z2
) s1
)
SELECT t1.Getdup, t1.CustomerName, t1.CustomerAdd
FROM mytable t1
INNER JOIN numTable ON t1.getdup >= numTable.num
ORDER BY CustomerName, CustomerAdd
Results:
| Getdup | CustomerName | CustomerAdd |
|--------|--------------|---------------|
| 2 | Bob | 987 SomeWhere |
| 2 | Bob | 987 SomeWhere |
| 2 | Bob | 987 SomeWhere |
| 1 | John | 123 SomeWhere |
| 1 | John | 123 SomeWhere |
--------------------------------------------------------------------------
ORIGINAL ANSWER
EDIT: After further clarification of the problem, this won't duplicate rows, this will only duplicate the data in a column.
Something like one of these might work.
T-SQL
SELECT replicate(mycolumn,getdup) AS x
FROM mytable
MySQL
SELECT repeat(mycolumn,getdup) AS x
FROM mytable
Oracle SQL
SELECT rpad(mycolumn,getdup*length(mycolumn),mycolumn) AS x
FROM mytable
PostgreSQL
SELECT repeat(mycolumn,getdup+1) AS x
FROM mytable
If you can provide more details for exactly what you want and what you're working with, we might be able to help you better.
NOTE 2: Depending on what you need, you may need to do some math magic. You say above if GetDup is 1 then you want one duplicate. If that means that your output should be GetDup``GetDup, then you'll want to add one in the repeat(),replicate() or rpad() functions. ie replicate(mycolumn,getdup+1). Oracle SQL will be a little different, since it uses rpad().
In standard SQL you can use a recursive CTE:
with recursive cte as (
select t.dup, . . .
from t
union all
select cte.dup - 1, . . .
from cte
where cte.dup > 1
)
select *
from cte;
Of course, not all databases support recursive CTEs (and the recursive keyword is not used in some of them).
So, you want recursive solution :
with t as (
select Getdup, CustomerName, CustomerAdd, 0 as id
from table
union all
select Getdup, CustomerName, CustomerAdd, id + 1
from t
where id < getdup
)
insert into table (col1, col2, col3)
select Getdup, CustomerName, CustomerAdd
from t
order by getdup
option (maxrecursion 0);
I have a following table (simplified version) in SQLServer.
Table Events
-----------------------------------------------------------
| Room | User | Entered | Exited |
-----------------------------------------------------------
| A | Jim | 2014-10-10T09:00:00 | 2014-10-10T09:10:00 |
| B | Jim | 2014-10-10T09:11:00 | 2014-10-10T09:22:30 |
| A | Jill | 2014-10-10T09:00:00 | NULL |
| C | Jack | 2014-10-10T09:45:00 | 2014-10-10T10:00:00 |
| A | Jack | 2014-10-10T10:01:00 | NULL |
.
.
.
I need to create a query that returns person's whereabouts in given timestamps.
For an example: Where was (Jim at 2014-10-09T09:05:00), (Jim at 2014-10-10T09:01:00), (Jill at 2014-10-10T09:10:00), ...
The result set must contain the given User and Timestamp as well as the found room (if any).
------------------------------------------
| User | Timestamp | WasInRoom |
------------------------------------------
| Jim | 2014-10-09T09:05:00 | NULL |
| Jim | 2014-10-09T09:01:00 | A |
| Jim | 2014-10-10T09:10:00 | A |
The number of User-Timestamp tuples can be > 10 000.
The current implementation retrieves all records from Events table and does the search in Java code. I am hoping that I could push this logic to SQL. But how?
I am using MyBatis framework to create SQL queries so the tuples can be inlined to the query.
The basic query is:
select e.*
from events e
where e.user = 'Jim' and '2014-10-09T09:05:00' >= e.entered and ('2014-10-09T09:05:00' <= e.exited or e.exited is NULL) or
e.user = 'Jill' and '2014-10-10T09:10:00 >= e.entered and ('2014-10-10T09:10:00' <= e.exited or e.exited is NULL) or
. . .;
SQL Server can handle ridiculously large queries, so you can continue in this vein. However, if you have the name/time values in a table already (or it is the result of a query), then use a join:
select ut.*, t.*
from usertimes ut left join
events e
on e.user = ut.user and
ut.thetime >= et.entered and (ut.thetime <= exited or ut.exited is null);
Note the use of a left join here. It ensures that all the original rows are in the result set, even when there are no matches.
Answers from Jonas and Gordon got me on track, I think.
Here is query that seems to do the job:
CREATE TABLE #SEARCH_PARAMETERS(User VARCHAR(16), "Timestamp" DATETIME)
INSERT INTO #SEARCH_PARAMETERS(User, "Timestamp")
VALUES
('Jim', '2014-10-09T09:05:00'),
('Jim', '2014-10-10T09:01:00'),
('Jill', '2014-10-10T09:10:00')
SELECT #SEARCH_PARAMETERS.*, Events.Room FROM #SEARCH_PARAMETERS
LEFT JOIN Events
ON #SEARCH_PARAMETERS.User = Events.User AND
#SEARCH_PARAMETERS."Timestamp" > Events.Entered AND
(Events.Exited IS NULL OR Events.Exited > #SEARCH_PARAMETERS."Timestamp"
DROP TABLE #SEARCH_PARAMETERS
By declaring a table valued parameter type for the (user, timestamp) tuples, it should be simple to write a table valued user defined function which returns the desired result by joining the parameter table and the Events table. See http://msdn.microsoft.com/en-us/library/bb510489.aspx
Since you are using MyBatis it may be easier to just generate a table variable for the tuples inline in the query and join with that.
I am trying to make some sense of a xBase type database with some 2000 tables. Rather than importing them all into a SQL Server database, I wanted to import the tables one-by-one using a 'SELECT INTO tmpDBF' statement, then extract what I want to know like table structure and value ranges for each of the columns. Then, when I import the next table I want to be able to run the same query against a differently structured tmpDBF table.
I was hoping to do this using a cross apply, but I come up against the above error message.
select cols.column_name 'Name', cols.data_type 'Type', mv.minV 'Minimum'
from information_schema.columns cols
cross apply (select MIN(cols.column_name) minV FROM tmpDBF ) mv
where cols.table_name = 'tmpDBF'
Is there way to restructure the query or did I turn into a dead-end street?
Added on October 6:
Given tmpDBF
Who | Zip
--------|------
Charlie | 97689
Foxtrot | 92143
Delta | 12011
I would like to see the following result
Name | Type | Minimum | Maximum
-----|---------|---------|--------
who | varchar | Charlie | Foxtrot
Zip | int | 12011 | 96789
I realise that the Minimum and Maximum columns need to be cast as varchars.
This is not possible for two reasons.
you cannot dynamically change a column name in a query
you cannot mix multiple datatypes in a single column.
But to get you something similar to what you are looking for you can flip the problem around like this:
SQL Fiddle
MS SQL Server 2008 Schema Setup:
CREATE TABLE dbo.a(c1 INT, c2 INT, c3 DATE);
INSERT INTO dbo.a VALUES(1,2,'2013-04-05'),(4,5,'2010-11-10'),(7,8,'2012-07-09');
Query 1:
SELECT
MIN(c1) c1_min,MAX(c1) c1_max,
MIN(c2) c2_min,MAX(c2) c2_max,
MIN(c3) c3_min,MAX(c3) c3_max
FROM dbo.a;
Results:
| C1_MIN | C1_MAX | C2_MIN | C2_MAX | C3_MIN | C3_MAX |
|--------|--------|--------|--------|------------|------------|
| 1 | 7 | 2 | 8 | 2010-11-10 | 2013-04-05 |
That gives you all the column minima and maxima in a single row. (It's not dynamic yet. Stay with me...)
To make it a little more readable you can use a sort of UNPIVOT like this:
Query 2:
SELECT
CASE X.FN WHEN 1 THEN 'MIN' ELSE 'MAX' END AS FN,
CASE X.FN WHEN 1 THEN c1_min ELSE c1_max END AS c1,
CASE X.FN WHEN 1 THEN c2_min ELSE c2_max END AS c2,
CASE X.FN WHEN 1 THEN c3_min ELSE c3_max END AS c3
FROM(
SELECT
MIN(c1) c1_min,MAX(c1) c1_max,
MIN(c2) c2_min,MAX(c2) c2_max,
MIN(c3) c3_min,MAX(c3) c3_max
FROM dbo.a)AGG
CROSS JOIN (VALUES(1),(2))X(FN)
ORDER BY X.FN;
Results:
| FN | C1 | C2 | C3 |
|-----|----|----|------------|
| MIN | 1 | 2 | 2010-11-10 |
| MAX | 7 | 8 | 2013-04-05 |
Now to make it dynamic we have to build that query on the fly, like this:
Query 3:
DECLARE #cmd NVARCHAR(MAX);
SET #cmd =
'SELECT CASE X.FN WHEN 1 THEN ''MIN'' ELSE ''MAX'' END AS FN'+
(SELECT ',CASE X.FN WHEN 1 THEN '+name+'_min ELSE '+name+'_max END AS '+name
FROM sys.columns WHERE object_id = OBJECT_ID('dbo.a')
FOR XML PATH(''),TYPE).value('.','NVARCHAR(MAX)')+
' FROM(SELECT '+
STUFF((SELECT ',MIN('+name+') '+name+'_min,MAX('+name+') '+name+'_max'
FROM sys.columns WHERE object_id = OBJECT_ID('dbo.a')
FOR XML PATH(''),TYPE).value('.','NVARCHAR(MAX)'),1,1,'')+
' FROM dbo.a)AGG CROSS JOIN (VALUES(1),(2))X(FN) ORDER BY X.FN;';
EXEC(#cmd);
Results:
| FN | C1 | C2 | C3 |
|-----|----|----|------------|
| MIN | 1 | 2 | 2010-11-10 |
| MAX | 7 | 8 | 2013-04-05 |
This query takes the columns of the table at runtime, builds the appropriate query dynamically and executes it. It contains the table name ('dbo.a') in three places. If you want it to work with different tables you need to replace all three.
Try something like
select cols.column_name 'Name', cols.data_type 'Type', mv.minV 'Minimum'
from information_schema.columns cols
cross apply (select MIN(cols.column_name) minV FROM tmpDBF
WHERE tmpDBF.CommonCol = cols.CommonCol) mv
where cols.table_name = 'tmpDBF'