I want have a query with a column that is a hardcoded value not from a table, can this be done? I need it basically as a placeholder that I am going to come back to later and fill in.
example:
SELECT
hat,
shoe,
boat,
somevalue = 0 as placeholder
FROM
objects
then I would loop through this query later and fill in the placeholder
in this example someValue is not a field in objects, I need to fake it. I am doing this in coldfusion and using two datasources to complete one query. I have tried the space() function but have been unable to get it to work.
Thanks.
SELECT
hat,
shoe,
boat,
0 as placeholder
FROM
objects
And '' as placeholder for strings.
This should work on most databases. You can also select a blank string as your extra column like so:
Select
Hat, Show, Boat, '' as SomeValue
From
Objects
For varchars, you may need to do something like this:
select convert(varchar(25), NULL) as abc_column into xyz_table
If you try
select '' as abc_column into xyz_table
you may get errors related to truncation, or an issue with null values, once you populate.
The answers above are correct, and what I'd consider the "best" answers. But just to be as complete as possible, you can also do this directly in CF using queryAddColumn.
See http://www.cfquickdocs.com/cf9/#queryaddcolumn
Again, it's more efficient to do it at the database level... but it's good to be aware of as many alternatives as possible (IMO, of course) :)
SELECT
hat,
shoe,
boat,
0 as placeholder -- for column having 0 value
FROM
objects
--OR '' as Placeholder -- for blank column
--OR NULL as Placeholder -- for column having null value
Thank you, in PostgreSQL this works for boolean
SELECT
hat,
shoe,
boat,
false as placeholder
FROM
objects
Related
I have been using sql for quite a time but unable to figure out below query logic.
I'm extracting two values
First_name i.e abc
FIRST_NAMES_LIST (list containing first names) i.e ['abc','abc','cba','dba'] (this may contain junk values also in between strings)
I trying to search first_name in first_name_list and return 1 or 0, using below logic
CASE FIRST_NAME in FIRST_NAMES_LIST then 1
else 0
but this isn't giving correct result
Can somebody please help.
Thanks,
Naseer
Look this information:
https://www.techonthenet.com/oracle/functions/instr.php
INSTR is a function which return <> 0 if your parameter match. If not it return 0.
I no have any clear example in your ennunciate to give you the correct answer. See the functionalities.
Regards!
Ideally you would parse out your json into a table object ( I don't know how to do that in Oracle) and then search your table object where the object contains the value, but that is pretty expensive. It would be more robust and would be able to handle special characters/corner cases better.
On the other hand, if the names are going to stay simple (ie, no quote marks ' or commas), you could use a LIKE expression and search the string.
CASE WHEN FIRST_NAMES_LIST LIKE '%''' + FIRST_NAME + '''%' THEN 1 ELSE 0 END
Yes im currently using INSTR but query is taking bit of time. hope resolves this issue. thanks.
I am trying to connect a Filemaker DB to Firebird SQL DB in both ways import to FM and export back to Firebird DB.
So far it works using the MBS Plug-in but FM 13 Pro canot handle NULL.
That means that for example Timestamp fields that are empty (NULL) produce a "0" value.
Thats means in Time something like 01.01.1889 00:00:00.
So my idea was to simply ignore fields containing NULL.
But here my poor knowlege stops.
First I thought I can do this with WHERE, but this is ignoring whole records sets:
SELECT * FROM TABLE WHERE FIELD IS NOT NULL
Also I tried to filter it later on like this:
If (IsEmpty (MBS("SQL.GetFieldAsDateTime"; $command; "FIELD") ) = 0 ; MBS("SQL.GetFieldAsDateTime"; $command; "FIELD"))
With no result either.
This is a direct answer to halfbit's suggestion, which is correct but not for this SQL dialect. In a query to provide a replacement value when a field is NULL you need to use COALESCE(x,y). Where if X is null, Y will be used, and if Y is null then the field is NULL. Thats why it is common for me to use it like COALESCE(table.field,'') such that a constant is always outputted if table.field happens to be NULL.
select COALESCE(null,'Hello') as stackoverflow from rdb$database
You can use COALESCE() for more than two arguments, I just used two for conciseness.
I dont know the special SQL dialect, but
SELECT field1, field2, value(field, 0), ...FROM TABLE
should help you:
value gives the first argument, ie, your field if it is NOT NULL or the second argument if it is.
I am working with a table that contains two versions of stored information. To simplify it, one column contains the old description of a file run while another column contains the updated standard for displaying ran files. It gets more complicated in that the older column can have multiple standards within itself. The table:
Old Column New Column
Desc: LGX/101/rpt null
null Home
Print: LGX/234/rpt null
null Print
null Page
I need to combine the two columns into one, but I also need to delete the "Print: " and "Desc: " string from the beginning of the old column values. Any suggestions? Let me know if/when I'm forgetting something you need to know!
(I am writing in Cache SQL, but I'd just like a general approach to my problem, I can figure out the specifics past that.)
EDIT: the condition is that if substr(oldcol,1,5) = 'desc: ' then substr(oldcol,6)
else if substr(oldcol,1,6) = 'print: ' then substr(oldcol,7) etc. So as to take out the "desc: " and the "print: " to sanitize the data somewhat.
EDIT2: I want to make the table look like this:
Col
LGX/101/rpt
Home
LGX/234/rpt
Print
Page
It's difficult to understand what you are looking for exactly. Does the above represent before/after, or both columns that need combining/merging.
My guess is that COALESCE might be able to help you. It takes a bunch of parameters and returns the first non NULL.
It looks like you're wanting to grab values from new if old is NULL and old if new is null. To do that you can use a case statement in your SQL. I know CASE statements are supported by MySQL, I'm not sure if they'll help you here.
SELECT (CASE WHEN old_col IS NULL THEN new_col ELSE old_col END) as val FROM table_name
This will grab new_col if old_col is NULL, otherwise it will grab old_col.
You can remove the Print: and Desc: by using a combination of CharIndex and Substring functions. Here it goes
SELECT CASE WHEN CHARINDEX(':',COALESCE(OldCol,NewCol)) > 0 THEN
SUBSTRING(COALESCE(OldCol,NewCol),CHARINDEX(':',COALESCE(OldCol,NewCol))+1,8000)
ELSE
COALESCE(OldCol,NewCol)
END AS Newcolvalue
FROM [SchemaName].[TableName]
The Charindex gives the position of the character/string you are searching for.
So you get the position of ":" in the computed column(Coalesce part) and pass that value to the substring function. Then add +1 to the position which indicates the substring function to get the part after the ":". Now you have a string without "Desc:" and "Print:".
Hope this helps.
Is there something I can put in my WHERE clause to only select fields from a column where that field does not contain a certain string. In this case, I am looking through to make sure the codes in this particular field do not have a "cs" in it. The code could be something like cs023 or bg425, just to give you a little bit more of an idea what I'm looking to do.
You can use
WHERE [column] NOT LIKE '%cs%'
Replace [column] with your column name.
Just a couple of alternatives (for folks who like VB's InStr() or JS' .indexOf() type syntax).
WHERE CHARINDEX('cs', [column]) = 0;
...or...
WHERE PATINDEX('%cs%', [column]) = 0;
You might also want to deal with NULL values:
WHERE COALESCE([column], '') NOT LIKE '%cs%';
I'm selecting a value out of a table that can either be an integer or a nvarchar. It's stored as nvarchar. I want to conditionally call a function that will convert this value if it is an integer (that is, if it can be converted into an integer), otherwise I want to select the nvarchar with no conversion.
This is hitting a SQL Server 2005 database.
select case
when T.Value (is integer) then SomeConversionFunction(T.Value)
else T.Value
end as SomeAlias
from SomeTable T
Note that it is the "(is integer)" part that I'm having trouble with. Thanks in advance.
UPDATE
Check the comment on Ian's answer. It explains the why and the what a little better. Thanks to everyone for their thoughts.
select case
when ISNUMERIC(T.Value) then T.Value
else SomeConversionFunction(T.Value)
end as SomeAlias
Also, have you considered using the sql_variant data type?
The result set can only have one type associated with it for each column, you will get an error if the first row converts to an integer and there are strings that follow:
Msg 245, Level 16, State 1, Line 1
Conversion failed when converting the nvarchar value 'word' to data type int.
try this to see:
create table testing
(
strangevalue nvarchar(10)
)
insert into testing values (1)
insert into testing values ('word')
select * from testing
select
case
when ISNUMERIC(strangevalue)=1 THEN CONVERT(int,strangevalue)
ELSE strangevalue
END
FROM testing
best bet is to return two columns:
select
case
when ISNUMERIC(strangevalue)=1 THEN CONVERT(int,strangevalue)
ELSE NULL
END AS StrangvalueINT
,case
when ISNUMERIC(strangevalue)=1 THEN NULL
ELSE strangevalue
END AS StrangvalueString
FROM testing
or your application can test for numeric and do your special processing.
You can't have a column that is sometimes an integer and sometimes a string. Return the string and check it using int.TryParse() in the client code.
ISNUMERIC. However, this accepts +, - and decimals so more work is needed.
However, you can't have the columns as both datatypes in one go: you'll need 2 columns.
I'd suggest that you deal with this in your client or use an ISNUMERIC replacement
IsNumeric will get you part of the way there. You can then add some further code to check whether it is an integer
for example:
select top 10
case
when isnumeric(mycolumn) = 1 then
case
when convert(int, mycolumn) = mycolumn then
'integer'
else
'number but not an integer'
end
else
'not a number'
end
from mytable
To clarify some other answers, your SQL statement can't return different data types in one column (it looks like the other answers are saying you can't store different data types in one column - yours are all strign represenations).
Therefore, if you use ISNUMERIC or another function, the value will be cast as a string in the table that is returned anyway if there are other strigns being selected.
If you are selecting only one value then it could return a string or a number, however your front end code will need to be able to return the different data types.
Just to add to some of the other comments about not being able to return different data types in the same column... Database columns should know what datatype they are holding. If they don't then that should be a BIG red flag that you have a design problem somewhere, which almost guarantees future headaches (like this one).