After running my query I get 1 column result as
5
6
98
101
Is there a way to store this result as array so that I can use it later
in queries like
WHERE NOT IN ('5','6','98','101')
I am aware of storing single variable results but is this possible?
I can not use #Table variable as I will be rerunning the query again in the future and it goes out of scope
There are multiple way of storing those column data like using Temporary Tables or View or Table valued function but IMO there is no need of storing that column data anywhere. You can directly use that column in any query saying below (or) perform a JOIN which would be much better option than NOT IN
select * from
table2
where some_column not in (select column1 from this_table);
While this method is not recommended, storing an array in a single column can be done using CSV's(Comma Separated Values). Simply create a VARCHAR array and store it by storing a string containing the values in a specific order. Basically store all of your values into a string with each value being separated by a comma in that string. Store that into a column of your choice. You can later fetch the string and parse it with a string parser i.e using the .split() function in python. AGAIN I do not recommend doing this, I would instead use multiple columns, one referring to each value and access them that way instead
Using separate columns would make it easy to use in a Stored Procedure.
Related
I have a form where people can type in a start and end date, as well as a column name prefix.
In the backend, I want to do something along the lines of
SELECT *, CAST('{{startDate}}' AS TIMESTAMP) AS ({{prefix}} + '_startDate')
Is this possible? Basically, I want to dynamically create the name of the new column. The table is immediately returned to the user, so I don't want to mutate the underlying table itself. Thanks!
You can execute dynamic query that you have prepared by using EXECUTE keyword, otherwise it is not possible to have dynamic structure of SQL.
Since you are preparing your SQL outside database, you can use something like:
SELECT *, CAST('{{startDate}}' AS TIMESTAMP) AS {{prefix}}_startDate
Assuming that {{prefix}} is replaced with some string by your template before it is sent to database.
I would like to ask if it is possible to do this:
For example the search string is '009' -> (consider the digits as string)
is it possible to have a query that will return any occurrences of this on the database not considering the order.
for this example it will return
'009'
'090'
'900'
given these exists on the database. thanks!!!!
Use the Like operator.
For Example :-
SELECT Marks FROM Report WHERE Marks LIKE '%009%' OR '%090%' OR '%900%'
Split the string into individual characters, select all rows containing the first character and put them in a temporary table, then select all rows from the temporary table that contain the second character and put these in a temporary table, then select all rows from that temporary table that contain the third character.
Of course, there are probably many ways to optimize this, but I see no reason why it would not be possible to make a query like that work.
It can not be achieved in a straight forward way as there is no sort() function for a particular value like there is lower(), upper() functions.
But there is some workarounds like -
Suppose you are running query for COL A, maintain another column SORTED_A where from application level you keep the sorted value of COL A
Then when you execute query - sort the searchToken and run select query with matching sorted searchToken with the SORTED_A column
I have a table Names
Id Name
+----+---------------+
1 John
2 Kate
3 Mark
I want to create a stored procedure that does the following:
1) take a list of names as string as an input parameter
I have done some researches about this but couldn't find the best way to do it. I will call the stored procedure from the entity framework in a C# application. I was thinking of passing the names in one string separated with a comma and the split them in the procedure. But can't figure out how this is done.
2) for each name in the list, if the name does not exist in the Name column, insert a new row for it.
How can I do a switch case if it exists and insert it if not
3) Select * rows that are in the input list.
After adding all the missing Names, I want to select all the names that were in the input list with their id
Can this be done in one stored procedure, or do I have to divide them into multiple.
I am looking for hints on how to do each step, and if they can be combined.
Thanks
Keep your DB side lean and leave logic on the app side, especially if you have grumpy DBA's.
Use a MERGE/Upsert instead.
Check out this SO post.
If you pass a comma delimited list into a stored procedure as a parameter, you are going to need to understand how to use charindex, left, substring and right
As you split out each name - you would add them into a temporary table or a table valued variable.
Your decision about whether to insert the new names into the Names table would be made using an exists() subquery on an insert statement.
You could then, finally, fashion a select statement to join your temp table/table valued variable back to your Names table to pull out all of the keys (including the new ones) and pass them back to your front end.
I need to execute a simple query:
SELECT * FROM MyTable WHERE Id IN (:ids)
Obviously, it returns the set of records which have their primary key 'Id' in the given list. How can I pass an array of integer IDs into ADOQuery.Parameters for parameter 'ids'? I have tried VarArray - it does not work. Parameter 'ids' has FieldType = ftInteger by default, if it matters.
There is no parameter type that can be used to pass a list of values to in. Unfortunately, this is one of the shortcomings of parameterized SQL.
You'll have to build the query from code to either generate the list of values, or generate a list of parameters which can then be filled from code. That's because you can pass each value as a different parameter, like this:
SELECT * FROM MyTable WHERE Id IN (:id1, :id2, :id3)
But since the list will probably have a variable size, you'll have to alter the SQL to add parameters. In that case it is just as easy to generate the list of values, although parametereized queries may be cached better, depending on which DB you use.
The IN param just takes a comma separated string of values like (1,2,3,4,5) so I assume you set the datatype to ftstring and just build the string and pass that...? Not tried it but it's what I would try...
I have a table which has essentially boolean values in a legacy database. The column names are stored as string values in another table so I need to match the column names of one table to a string value in another table. I know there has to be a way to do this directly with SQL in SQL Server but it is beyond me.
My initial thought was to use PIVOT but it is not enabled by default and enabling it would likely be a difficult process with pushing that change to the Production database. I would prefer to use what is enabled by default.
I am considering using COALESCE to translate the boolean value to the string that value that I need. This will be a manual process.
I think I will also use a table variable to insert the results of the first query into that variable and use those results to do the second query. I still have the problem that the columns are on a single row so I wish I could easily pivot the values to put the column names in the result set as strings. But if I could easily do that I could easily write the query with a sub-select.
Any tips are welcome.
Checkout Sysobjects and SysColumns in SQL Server. They are 2 SQL tables that gives you the names of the tables in your DB and the names of the columns that go with that table.
The system view INFORMATION_SCHEMA.COLUMNS will also give you what you want.
You can build a SQL string and then execute that string as a query. Not the prettiest by any means but I think it would work the way you want it to. You would just use a cursor or while loop to build the string.
If you're comfortable with .Net you could just write your own stored proc in your language of choice and manipulate the data in code instead.
Heres a link to get started
CLR Stored Procedures
I'm not quite sure I understand how your design is currently put together (could you post an example?), but the information_schema.columns view will give you a table containing all the column names as string values. If you join your second table against that I think you'll probably get what you need.
For Example, i have a table STATEtbl having 3 columns and i want to get all the column names of this table as ROW values... i use the below query
Select SC.name as Columns from Syscolumns SC
Join Sysobjects SO On SC.id = SO.Id
where Object_name(SO.Id) = 'STATEtbl'
Result of the query:
Columns
--------
State
StateCode
StateFullName