Say num is a column that contains integers.
Is there difference between:
SELECT num, (num * 2) AS 2num and,
SELECT num, 2num = (num * 2)?
They both produce the same result, are they interchangeable?
None. AS is standard SQL, while = works on SQL Server only.
I [personally] would go with the standard.
AS is used across or SQL types,whether its Oracle,MySql,Postgresql, while = is another keyword that can serve the same purpose but it is unique to TSQL.
Related
I'm trying to figure out a way, using SQL, to query for values that go out to, say, 5 or more decimal places. In other words, I want to see only results that have 5+ decimal places (e.g. 45.324754) - the numbers before the decimal are irrelevant, however, I still need to see the full number. Is this possible? Any help if appreciated.
Assuming your DBMS supports FLOOR and your datatype conversion model supports this multiplication, you can do this:
SELECT *
FROM Table
WHERE FLOOR(Num*100000)!=Num*100000
This has the advantage of not requiring a conversion to a string datatype.
On SQL Server, you can specify:
SELECT *
FROM Table
WHERE Value <> ROUND(Value,4,1);
For an ANSI method, you can use:
SELECT *
FROM Table
WHERE Value <> CAST(Value*100000.0 AS INT) / 100000.0;
Although this method might cause an overflow if you're working with large numbers.
I imagine most DBMSs have a round function
SELECT *
FROM YourTable
WHERE YourCol <> ROUND(YourCol,4)
This worked for me in SQL Server:
SELECT *
FROM YourTable
WHERE YourValue LIKE '%._____%';
select val
from tablename
where length(substr(val,instr(val, '.')+1)) > 5
This is a way to do it in oracle using substr and instr
You can use below decode statement to identify maximum decimal present in database table
SELECT max(decode(INSTR(val,'.'), 0, 0, LENGTH(SUBSTR(val,INSTR(val,'.')+1)))) max_decimal
FROM tablename A;
I have a SQL command in SQL-Server, and I need to migrate it to Oracle, but there's a part of the sql that I don't understand how to translate it. Here's the sql:
select * from myTable where id = #id and (Mask & #Mask) = #Mask
I think that It's a binary mask, but I'm not quite sure and I don't know if I can do that in Oracle, could you help me?
Thank you very much
You are correct - this is binary mask.
Oracle provides only BITAND function, others (BITOR, BITXOR) must be self made.
Using BITAND function this select will return value 2:
SELECT BITAND(6,2) FROM DUAL;
So your query in Oracle can be rewritten in following way:
select * from myTable where id = :id and BITAND(Mask, :Mask) = :Mask
I have the following data:
[sequences]
/a1
/a2
/a3
...
/a10
The query SELECT * FROM sequences WHERE nbr <= '/a10' should return the list above, instead it returns:
[results]
/a1
/a10
How do I make it return all the rows in the above list?
It works as it should. To compare the numeric value, you'll have to convert these to numbers somehow. A good start would be to use substr(yourfieldname, 3) to cut of the/a. Then you can useconvert` to typecast it to int, so your final query will look something like:
select * from sequences where convert(int, substr(nbr, 3)) <= 10
Mind that the exact functions and rules for converting strings to ints may very per dbms. This illustrates the general idea, though.
SELECT *
FROM sequences
WHERE toInt(substring (nbr, 2)) <= 10;
Name and syntax of 'substring'-function and 'toInt' will vary from db-implementation to db-implementation.
I have a zipcode stored in a text field (string) and would like to select only the last 3 digits of the value in my select statement. is this possible? Is there a standard way of doing this so that the SQL is interchangeable accross databases? I will be using it in production on Oracle, but i test on Interbase (yes, yes, i know, two totally diff DBs, but thats what i am doing)
thanks for any help you can offer
Assuming the zipcodes all have the same length, you can use substr.
If they don't have the same length, you have to do similar things with the strlen function.
Interbase does not have a built-in substring function, but it does have a UDF (user defined function) called SUBSTR in lib_udf.dll that works like this:
select substr(clients.lastname, 1, 10)
from clients
You declare the UDF like this:
DECLARE EXTERNAL FUNCTION SUBSTR
CSTRING(80),
SMALLINT,
SMALLINT
RETURNS CSTRING(80) FREE_IT
ENTRY_POINT 'IB_UDF_substr' MODULE_NAME 'ib_udf';
Oracle does have a built-in substr function that you use like this:
select substr(clients.lastname, 1, 10)
from clients
--jeroen
This depends on how your storing the zip code. If you are using 5 digits only
then this should work for Oracle and may work for Interbase.
select * from table where substr(zip,3,3) = '014'
IF you store Zip + 4 and you want the last 3 digits and some are 5 digits and some are 9 digits you would have to do the following.
select * from table where substr(zip,length(zip) -2,3) = '014'
and one option that may work better in both databases is
select * from table where zip like '%014'
I have stored values in my database that look like 5XXXXXX, where X can be any digit. In other words, I need to match incoming SQL query strings like 5349878.
Does anyone have an idea how to do it?
I have different cases like XXXX7XX for example, so it has to be generic. I don't care about representing the pattern in a different way inside the SQL Server.
I'm working with c# in .NET.
You can write queries like this in SQL Server:
--each [0-9] matches a single digit, this would match 5xx
SELECT * FROM YourTable WHERE SomeField LIKE '5[0-9][0-9]'
stored value in DB is: 5XXXXXX [where x can be any digit]
You don't mention data types - if numeric, you'll likely have to use CAST/CONVERT to change the data type to [n]varchar.
Use:
WHERE CHARINDEX(column, '5') = 1
AND CHARINDEX(column, '.') = 0 --to stop decimals if needed
AND ISNUMERIC(column) = 1
References:
CHARINDEX
ISNUMERIC
i have also different cases like XXXX7XX for example, so it has to be generic.
Use:
WHERE PATINDEX('%7%', column) = 5
AND CHARINDEX(column, '.') = 0 --to stop decimals if needed
AND ISNUMERIC(column) = 1
References:
PATINDEX
Regex Support
SQL Server 2000+ supports regex, but the catch is you have to create the UDF function in CLR before you have the ability. There are numerous articles providing example code if you google them. Once you have that in place, you can use:
5\d{6} for your first example
\d{4}7\d{2} for your second example
For more info on regular expressions, I highly recommend this website.
Try this
select * from mytable
where p1 not like '%[^0-9]%' and substring(p1,1,1)='5'
Of course, you'll need to adjust the substring value, but the rest should work...
In order to match a digit, you can use [0-9].
So you could use 5[0-9][0-9][0-9][0-9][0-9][0-9] and [0-9][0-9][0-9][0-9]7[0-9][0-9][0-9]. I do this a lot for zip codes.
SQL Wildcards are enough for this purpose. Follow this link: http://www.w3schools.com/SQL/sql_wildcards.asp
you need to use a query like this:
select * from mytable where msisdn like '%7%'
or
select * from mytable where msisdn like '56655%'