I have two tables.
NewTransaction_tb
OldTransaction_tb
I want to move the records from old to new table including date. But the OldTransaction_tb it doesn't have the Date column.
This is what I am trying.
For example
DECLARE #VarDate Datetime = CONVERT(datetime,GETDATE(),102)
INSERT INTO HQMatajer.dbo.NewTransaction_tb
SELECT
Name, class, Qualification, #VarDate //this #VarDate is not in OldTransaction_tb
FROM
HQMatajer.dbo.OldTransaction_tb
What is the solution for this scenario? Thanks,
You don't have to declare a variable for doing this, you can directly convert the string from the old table and insert to the new one.
INSERT into HQMatajer.dbo.NewTransaction_tb
SELECT Name,class,Qualification,CONVERT(datetime,GETDATE(),102)
FROM HQMatajer.dbo.OldTransaction_tb
You can use directly Date in select column
SELECT
Name,class,Qualification,CONVERT(datetime,GETDATE(),102)
See, the answer to this can be what you wrote or what others suggested.
The question is what you want in your result set.
For example, if you are processing a data set all at once, say entire of OldTransaction table, and you want that all the rows being transferred to NewTransaction should have the same DateTime, then it is preferred to do it by first declaring a variable and then calling it.
This is better than using the function in a SELECT clause because the function is then called once for every row. So if you have a billion rows in OldTransaction table then the function will be called a billion times and you will have a small speed impact.
But if your require all rows to have the exact date time of insertion, in case your insert takes a prolonged time over an hour or so, then there is no choice but to use the function within the SELECT statement.
SELECT
Name, Class, Qualification, CONVERT(Datetime, GETDATE(), 102)
FROM HQMatajer.dbo.OldTransaction_tb
Check this:
if table does not yet exist then use :
Select *
Into NewTransaction_tb
From
(select
* ,CONVERT(datetime, GETDATE(), 102) as Date
from
OldTransaction_tb) a
OR
if table already exists, then use :
insert into NewTransaction_tb
select
*, CONVERT(datetime, GETDATE(), 102) as Date
from
OldTransaction_tb
Related
I use a scheduled query in Big Query which appends data from the previous day to a Big Query table. The data from the previous day is not always available when my query runs, so, to make sure that I have all the data, I need to calculate the last date available in my Big Query table.
My first attempt was to write the following query :
SELECT *
FROM sourceTable
WHERE date >= (SELECT Max(date) from destinationTable)
When I run this query, only date >= max(date) is correctly exported. However, the query processes the entire sourceTable, and not only J - max(date). Therefore, the cost is higher than expected.
I also tried to declare a variable using "DECLARE" & "SET" (https://cloud.google.com/bigquery/docs/reference/standard-sql/scripting). This solution works fine and only J - max(date) is processed. However, BQ interprets a query with "DECLARE" as a script, so the results can't be exported automatically to a BQ table using scheduled queries.
DECLARE maxDate date;
SET maxDate = (SELECT Max(date) from destinationTable);
SELECT *
FROM sourceTable
WHERE date >= maxDate
Is there another way of doing what I would like? Or a way to declare a variable using "DECLARE" & "SET" in a scheduled query with a destination table?
Thanks!
Scripting query, when being scheduled, doesn't support setting a destination table for now. You need to use DDL/DML to make change to existing table.
DECLARE maxDate date;
SET maxDate = (SELECT Max(date) from destinationTable);
CREATE OR REPLACE destinationTable AS
SELECT *
FROM sourceTable
WHERE date >= maxDate
Is destinationTable partitioned? If not, can you recreate it as a partitioned table? If it is a partitioned table, and partitioned on the destinationTable.date column, you could do something like:
SELECT *
FROM sourceTable
WHERE date >= (SELECT MAX(_PARTITIONTIME) from destinationTable)
Since _PARTITIONTIME is a pseudo-column, there is no cost in running the subquery.
We still can't use scheduled scripting in BigQuery along with destination table.
But if your source table is date sharded then there is a workaround that can be used to achieve the desired solution (only required data scan based on an initial value from another table).
SELECT
*
FROM
sourceTable*
WHERE
_TABLE_SUFFIX >= (
SELECT
IFNULL(MAX(date),
'<default_date>')
FROM
destinationTable)
This will scan only shards that are greater than or equal to the maximum date of the destination table.
P.S. - source table is date sharded.
I want to be able to have todays date and time now in a table column
If my table is say Table1, basically it should display the time and date when
SELECT * FROM Table1 is run.
I've tried the following but they just show the time from the moment in time I assign the value to column
ALTER TABLE Table1
ADD TodaysDate DateTime NOT NULL DEFAULT GETDATE()
and
ALTER TABLE Table1
ADD TodaysDate DateTime
UPDATE Table1
SET TodaysDate = GETDATE()
Hope this is clear. any help is appreciated.
Thanks
In SQL Server you can use a computed column:
alter table table1 add TodaysDate as (cast(getdate() as date));
(use just getdate() for the date and time)
This adds a "virtual" column that gets calculated every time it is referenced. The use of such a thing is unclear. Well, I could imagine that if you are exporting the data to a file or another application, then it could have some use for this to be built-in.
I hope this clarifies your requirement.
The SQL Server columns with default values stores the values inside the table. When you select the values from table, the stored date time will be displayed.
There are 2 options I see without adding the column to the table itself.
You can use SELECT *, GETDATE() as TodaysDate FROM Table1
You can create a view on top of Table 1 with additional column like
CREATE VIEW vw_Table1
AS
SELECT *, GETDATE() as TodaysDate FROM dbo.Table1
then you can query the view like you mentioned (without column list)
SELECT * FROM vw_Table1
This will give you the date and time from the moment of the execution of the query.
I have a table in database which is already has the data, but now I added new column called Vol_Age and it has NULL value. I want that column filled by calculating Age, the data comes from Vol_Date_of_Birth column, I need a query that calculate the age and insert it to the Vol_Age column.
which we can use Insert or Update, and how we can do it?!
Please forgive me for my English.
Thanks
Keep in mind that since you added the column to the database, any values within that column will retain their value. As time goes on, you will need to keep updateding the values within the database.
Another approach would be to remove the column and make it a computed column instead. This way, the age is caculated at query time rather than from your last update.
ALTER TABLE tbname ADD Vol_Age AS DATEDIFF(YEAR, Vol_Date_Of_Birth, GETDATE())
Try using the DateDiff function:
SELECT DATEDIFF(year,GETDATE(),Vol_Age)
you can use this:
UPDATE Personal_Info SET vol_Age = (SELECT (DATEDIFF(YEAR, Vol_Date_Of_Birth,GETDATE()) + CONVERT(REAL,(DATEDIFF(month, Vol_Date_Of_Birth,GETDATE()) % 12))/12) AS AGE
FROM Personal_Info)
I got answers from different places and merged the answers to get this:
UPDATE Personal_Info SET vol_Age = (select convert(int,DATEDIFF(d, Vol_Date_of_Birth, getdate())/365.25));
I have a task to automatically bill all registered patients in PatientsInfo table an Annual Bill of N2,500 base on the DateCreated column.
Certainly I will use a stored procedure to insert these records into the PatientDebit table and create a SQL Job to perform this procedure.
How will I select * patients in PatientsInfo table where DateCreated is now 1 yr old for me to insert into another table PatientDebit.
I have my algorithm like this:
select date of registration for patients from PatientsInfo table
Add 1 year to their DateCreated
Is date added today? if yes,
Insert record into PatientDebit table with the bill of N2,500
If no, do nothing.
Please how do I write the script?
Use DATEADD, i.e.:
SELECT DATEADD(year, 1, '2006-08-30')
Ref.: http://msdn.microsoft.com/en-us/library/ms186819.aspx
Assuming the columns of the 2 tables are the same:
INSERT INTO PatientDebit
SELECT * from PatientsInfo WHERE DateCreated<DATEADD(year, -1, GETDATE())
Make sure you have an index on DateCreated if PatientsInfo has a lot of records as it could potentially be slow otherwise
there should be .add or addyear() function in sql. You add like .add(year, day, month). Read upon sql datetime add year, month and seconds. It is pretty straightforward. It is just like c#.
Dateadd(info). now time is. getdate().
This question is largely driven by curiosity, as I do have a working query (it just takes a little longer than I would like).
I have a table with 4 million rows. The only index on this table is an auto-increment BigInt ID. The query is looking for distinct values in one of the columns, but only going back 1 day. Unfortunately, the ReportDate column that is evaluated is not of the DateTime type, or even a BigInt, but is char(8) in the format of YYYYMMDD. So the query is a bit slow.
SELECT Category
FROM Reports
where ReportDate = CONVERT(VARCHAR(8), GETDATE(), 112)
GROUP BY Category
Note that the date converstion in the above statement is simply converting it to a YYYYMMDD format for comparison.
I was wondering if there was a way to optimize this query based on the fact that I know that the only data I am interested in is at the "bottom" of the table. I was thinking of some sort of recursive SELECT function which gradually grew a temporary table that could be used for the final query.
For example, in psuedo-sql:
N = 128
TemporaryTable = SELECT TOP {N} *
FROM Reports
ORDER BY ID DESC
/* Once we hit a date < Today, we can stop */
if(TemporaryTable does not contain ReportDate < Today)
N = N**2
Repeat Select
/* We now have a smallish table to do our query */
SELECT Category
FROM TemproaryTable
where ReportDate = CONVERT(VARCHAR(8), GETDATE(), 112)
GROUP BY Category
Does that make sense? Is something like that possible?
This is on MS SQL Server 2008.
I might suggest you do not need to convert the Date that is stored as char data in YYYYMMDD format; That format is inherently sortable all by itself. I would instead convert your date to output in that format.
Also, the way you have the conversion written, it is converting the current DateTime for every individual row, so even storing that value for the whole query could speed things up... but I think just converting the date you are searching for to that format of char would help.
I would also suggest getting the index(es) you need created, of course... but that's not the question you asked :P
Why not just create the index you need?
create index idx_Reports_ReportDate
on Reports(ReportDate, Category)
No, that doesn't make sense. The only way to optimize this query is to have a covering index for it:
CREATE INDEX ndxReportDateCategory ON Reports (ReportDate, Category);
Update
Considering your comment that you cannot modify the schema, then you should modify the schema. If you still can't, then the answer still applies: the solution is to have an index.
And finally, to answer more directly your question, if you have a strong correlation between ID and ReportData: the ID you seek is the biggest one that has a ReportDate smaller than the date you're after:
SELECT MAX(Id)
FROM Reports
WHERE ReportDate < 'YYYYMMDD';
This will do a reverse scan on the ID index and stop at the first ID that is previous to your desired date (ie. will not scan the entire table). You can then filter your reports base don this found max Id.
I think you will find the discussion on SARGability, on Rob Farley's Blog to be very interesting reading in relation to your post topic.
http://blogs.lobsterpot.com.au/2010/01/22/sargable-functions-in-sql-server/
An interesting alternative approach that does not require you to modify the existing column data type would be to leverage computed columns.
alter table REPORTS
add castAsDate as CAST(ReportDate as date)
create index rf_so2 on REPORTS(castAsDate) include (ReportDate)
One of the query patterns I occasionally use to get into a log table with similiar indexing to yours is to limit by subquery:
DECLARE #ReportDate varchar(8)
SET #ReportDate = Convert(varchar(8), GetDate(), 112)
SELECT *
FROM
(
SELECT top 20000 *
FROM Reports
ORDER BY ID desc
) sub
WHERE sub.ReportDate = #ReportDate
20k/4M = 0.5% of the table is read.
Here's a loop solution. Note: might want to make ID primary key and Reportdate indexed in the temp table.
DECLARE #ReportDate varchar(8)
SET #ReportDate = Convert(varchar(8), GetDate(), 112)
DECLARE #CurrentDate varchar(8), MinKey bigint
SELECT top 2000 * INTO #MyTable
FROM Reports ORDER BY ID desc
SELECT #CurrentDate = MIN(ReportDate), #MinKey = MIN(ID)
FROM #MyTable
WHILE #ReportDate <= #CurrentDate
BEGIN
SELECT top 2000 * INTO #MyTable
FROM Reports WHERE ID < #MinKey ORDER BY ID desc
SELECT #CurrentDate = MIN(ReportDate), #MinKey = MIN(ID)
FROM #MyTable
END
SELECT * FROM #MyTable
WHERE ReportDate = #ReportDate
DROP TABLE #MyTable