What is the equivalent of:
SELECT 0 as foo;
but for strings, is it:
SELECT '' as bar;
?
For more context, this is for a UNION ALL query
[edit]
SELECT NULL is what I was looking for.
In the top query I was doing: SELECT COUNT(DISTINCT(bar)),
But empty strings counted as a distinct char, NULL doesn't.
If you want an "equivalent" of SELECT 0 in string form, then it would be SELECT '0'::int.
If you are looking for a non-null string to represent 'no data,' SELECT '' AS something would suffice
When you call UNION ALL, the expectation is that the columns would align and the data sets would be concatenated along their column orders. Since you want to UNION ALL an integer and char, you will get an error:
edb=# select 0 as something union all select '' as something;
ERROR: invalid input syntax for type integer: ""
LINE 1: select 0 as something union all select '' as something;
^
Therefore, in order to UNION ALL, you'll want to cast your 0 as a char:
edb=# select 0::char as something union all select '' as something;
something
-----------
0
(2 rows)
Caveat
I'm not sure if this is really what you want to do, but if you're looking to UNION ALL the two sets, that's how you'd do it. However, there's a chance this would open up a can of worms -- is '' going to be considered equivalent to 0? And what will you do with non-zero values? Will you still cast those integers into strings? I think you'll need to think through those implications and try to find a way to sanitize your data.
In general, it might be better to work with NULL values if your design allows for it
Related
I need to replace the entire word with 0 if the word has any non-digit character. For example, if digital_word='22B4' then replace with 0, else if digital_word='224' then do not replace.
SELECT replace_funtion(digital_word,'has non numeric character pattern',0,digital_word)
FROM dual;
I tried decode, regexp_instr, regexp_replace but could not come up with the right solution.
Please advise.
Thank you.
the idea is simple - you need check if the value is numeric or not
script:
with nums as
(
select '123' as num from dual union all
select '456' as num from dual union all
select '7A9' as num from dual union all
select '098' as num from dual
)
select n.*
,nvl2(LENGTH(TRIM(TRANSLATE(num, ' +-.0123456789', ' '))),'0',num)
from nums n
result
1 123 123
2 456 456
3 7A9 0
4 098 098
see more articles below to see which way is better to you
How can I determine if a string is numeric in SQL?
https://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:15321803936685
How to tell if a value is not numeric in Oracle?
You might try the following:
SELECT CASE WHEN REGEXP_LIKE(digital_word, '\D') THEN '0' ELSE digital_word END
FROM dual;
The regular expression class \D matches any non-digit character. You could also use [^0-9] to the same effect:
SELECT CASE WHEN REGEXP_LIKE(digital_word, '\D') THEN '0' ELSE digital_word END
FROM dual;
Alternately you could see if the value of digital_word is made up of nothing but digits:
SELECT CASE WHEN REGEXP_LIKE(digital_word, '^\d+$') THEN digital_word ELSE '0' END
FROM dual;
Hope this helps.
The fastest way is to replace all digits with null (to simply delete them) and see if anything is left. You don't need regular expressions (slow!) for this, you just need the standard string function TRANSLATE().
Unfortunately, Oracle has to work around their own inconsistent treatment of NULL - sometimes as empty string, sometimes not. In the case of the TRANSLATE() function, you can't simply translate every digit to nothing; you must also translate a non-digit character to itself, so that the third argument is not an empty string (which is treated as a real NULL, as in relational theory). See the Oracle documentation for the TRANSLATE() function. https://docs.oracle.com/cd/E11882_01/server.112/e41084/functions216.htm#SQLRF06145
Then, the result can be obtained with a CASE expression (or various forms of NULL handling functions; I prefer CASE, which is SQL Standard):
with
nums ( num ) as (
select '123' from dual union all
select '-56' from dual union all
select '7A9' from dual union all
select '0.9' from dual
)
-- End of simulated inputs (for testing only, not part of the solution).
-- SQL query begins BELOW THIS LINE. Use your own table and column names.
select num,
case when translate(num, 'z0123456789', 'z') is null
then num
else '0'
end as result
from nums
;
NUM RESULT
--- ------
123 123
-56 0
7A9 0
0.9 0
Note: everything here is in varchar2 data type (or some other kind of string data type). If the results should be converted to number, wrap the entire case expression within TO_NUMBER(). Note also that the strings '-56' and '0.9' are not all-digits (they contain non-digits), so the result is '0' for both. If this is not what you needed, you must correct the problem statement in the original post.
Something like the following update query will help you:
update [table] set [col] = '0'
where REGEXP_LIKE([col], '.*\D.*', 'i')
I need to make 2 selects and put them together with an UNION. So far, so good. The problem is, for fields with no value, I can put just "0" instead of an actual column, but what do I put for string values? I know that the following example doesn't work:
Select field1, field2, 0, 0 from AnyTable
...
UNION
Select '','',sum(field3),sum(field4) from AnyTable2
...
So, what do I use instead of ' '?
An zero length string in Oracle is considered as NULL. You need to use NVL function to convert the NULL values into some value.
SQL> select nvl(null, 'This is null') val from dual;
VAL
------------
This is null
Note : Take care of the individual DATA TYPE of each column in the UNION
I want to compare two numbers. Let's take i.e. 1 and 2.
I've tried to write the following query but it simply doesn't work as expected (Toad says: ORA-00923: FROM keyword not found where expected):
SELECT 1 > 2 from dual
The DECODE is something like a Switch case, so how can I get the result of an expression evalutation (i.e. a number comparison) putting it in the select list?
I have found a solution using a functions instead of an expression in the SELECT LIST: i.e.
select DECODE(SIGN(actual - target)
, -1, 'NO Bonus for you'
, 0,'Just made it'
, 1, 'Congrats, you are a winner')
from some_table
Is there a more elegant way?
Also how do I compare two dates?
There is no boolean types in sql (at least in oracle).
you can use case:
SELECT CASE when 1 > 2 THEN 1 ELSE 0 END FROM dual
But your solution (decode) is also good, read here
The SIGN() function is indeed probably the best way of classifying (in)equality that may be of interest to you if you want to test a > b, a = b and a < b, and it will accept date-date or numeric-numeric as an argument.
I'd use a Case statement by preference, rather than a decode.
Select
case sign(actual-target)
when -1 then ...
when 0 then ...
when 1 then ...
end
SELECT (CASE
WHEN (SIGN(actual - target) > 0 ) THEN
'NO Bonus for you'
ELSE
'Just made it' END)
FROM dual
you can compare two dates with sql
METHOD (1):
SELECT TO_DATE('01/01/2012') - TO_DATE('01/01/2012')
FROM DUAL--gives zero
METHOD (2):
SELECT CASE
when MONTHS_BETWEEN('01/01/2012','01/01/2010') > 0
THEN 'FIRST IS GREATER'
ELSE 'SECOND IS GREATER OR EQUAL' END
FROM dual
sorry i cant format the code the formatting toolbar disappeared !
do any one know why?
I am trying to locate some problematic records in a very large Oracle table. The column should contain all numeric data even though it is a varchar2 column. I need to find the records which don't contain numeric data (The to_number(col_name) function throws an error when I try to call it on this column).
I was thinking you could use a regexp_like condition and use the regular expression to find any non-numerics. I hope this might help?!
SELECT * FROM table_with_column_to_search WHERE REGEXP_LIKE(varchar_col_with_non_numerics, '[^0-9]+');
To get an indicator:
DECODE( TRANSLATE(your_number,' 0123456789',' ')
e.g.
SQL> select DECODE( TRANSLATE('12345zzz_not_numberee',' 0123456789',' '), NULL, 'number','contains char')
2 from dual
3 /
"contains char"
and
SQL> select DECODE( TRANSLATE('12345',' 0123456789',' '), NULL, 'number','contains char')
2 from dual
3 /
"number"
and
SQL> select DECODE( TRANSLATE('123405',' 0123456789',' '), NULL, 'number','contains char')
2 from dual
3 /
"number"
Oracle 11g has regular expressions so you could use this to get the actual number:
SQL> SELECT colA
2 FROM t1
3 WHERE REGEXP_LIKE(colA, '[[:digit:]]');
COL1
----------
47845
48543
12
...
If there is a non-numeric value like '23g' it will just be ignored.
In contrast to SGB's answer, I prefer doing the regexp defining the actual format of my data and negating that. This allows me to define values like $DDD,DDD,DDD.DD
In the OPs simple scenario, it would look like
SELECT *
FROM table_with_column_to_search
WHERE NOT REGEXP_LIKE(varchar_col_with_non_numerics, '^[0-9]+$');
which finds all non-positive integers. If you wau accept negatiuve integers also, it's an easy change, just add an optional leading minus.
SELECT *
FROM table_with_column_to_search
WHERE NOT REGEXP_LIKE(varchar_col_with_non_numerics, '^-?[0-9]+$');
accepting floating points...
SELECT *
FROM table_with_column_to_search
WHERE NOT REGEXP_LIKE(varchar_col_with_non_numerics, '^-?[0-9]+(\.[0-9]+)?$');
Same goes further with any format. Basically, you will generally already have the formats to validate input data, so when you will desire to find data that does not match that format ... it's simpler to negate that format than come up with another one; which in case of SGB's approach would be a bit tricky to do if you want more than just positive integers.
Use this
SELECT *
FROM TableToSearch
WHERE NOT REGEXP_LIKE(ColumnToSearch, '^-?[0-9]+(\.[0-9]+)?$');
After doing some testing, i came up with this solution, let me know in case it helps.
Add this below 2 conditions in your query and it will find the records which don't contain numeric data
and REGEXP_LIKE(<column_name>, '\D') -- this selects non numeric data
and not REGEXP_LIKE(column_name,'^[-]{1}\d{1}') -- this filters out negative(-) values
Starting with Oracle 12.2 the function to_number has an option ON CONVERSION ERROR clause, that can catch the exception and provide default value.
This can be used for the test of number values. Simple set NULL when the conversion fails and filer all not NULL values.
Example
with num as (
select '123' vc_col from dual union all
select '1,23' from dual union all
select 'RV12P2000' from dual union all
select null from dual)
select
vc_col
from num
where /* filter numbers */
vc_col is not null and
to_number(vc_col DEFAULT NULL ON CONVERSION ERROR) is not null
;
VC_COL
---------
123
1,23
From http://www.dba-oracle.com/t_isnumeric.htm
LENGTH(TRIM(TRANSLATE(, ' +-.0123456789', ' '))) is null
If there is anything left in the string after the TRIM it must be non-numeric characters.
I've found this useful:
select translate('your string','_0123456789','_') from dual
If the result is NULL, it's numeric (ignoring floating point numbers.)
However, I'm a bit baffled why the underscore is needed. Without it the following also returns null:
select translate('s123','0123456789', '') from dual
There is also one of my favorite tricks - not perfect if the string contains stuff like "*" or "#":
SELECT 'is a number' FROM dual WHERE UPPER('123') = LOWER('123')
After doing some testing, building upon the suggestions in the previous answers, there seem to be two usable solutions.
Method 1 is fastest, but less powerful in terms of matching more complex patterns.
Method 2 is more flexible, but slower.
Method 1 - fastest
I've tested this method on a table with 1 million rows.
It seems to be 3.8 times faster than the regex solutions.
The 0-replacement solves the issue that 0 is mapped to a space, and does not seem to slow down the query.
SELECT *
FROM <table>
WHERE TRANSLATE(replace(<char_column>,'0',''),'0123456789',' ') IS NOT NULL;
Method 2 - slower, but more flexible
I've compared the speed of putting the negation inside or outside the regex statement. Both are equally slower than the translate-solution. As a result, #ciuly's approach seems most sensible when using regex.
SELECT *
FROM <table>
WHERE NOT REGEXP_LIKE(<char_column>, '^[0-9]+$');
You can use this one check:
create or replace function to_n(c varchar2) return number is
begin return to_number(c);
exception when others then return -123456;
end;
select id, n from t where to_n(n) = -123456;
I tray order by with problematic column and i find rows with column.
SELECT
D.UNIT_CODE,
D.CUATM,
D.CAPITOL,
D.RIND,
D.COL1 AS COL1
FROM
VW_DATA_ALL_GC D
WHERE
(D.PERIOADA IN (:pPERIOADA)) AND
(D.FORM = 62)
AND D.COL1 IS NOT NULL
-- AND REGEXP_LIKE (D.COL1, '\[\[:alpha:\]\]')
-- AND REGEXP_LIKE(D.COL1, '\[\[:digit:\]\]')
--AND REGEXP_LIKE(TO_CHAR(D.COL1), '\[^0-9\]+')
GROUP BY
D.UNIT_CODE,
D.CUATM,
D.CAPITOL,
D.RIND ,
D.COL1
ORDER BY
D.COL1
Is there an equivalent to IsDate or IsNumeric for uniqueidentifier (SQL Server)?
Or is there anything equivalent to (C#) TryParse?
Otherwise I'll have to write my own function, but I want to make sure I'm not reinventing the wheel.
The scenario I'm trying to cover is the following:
SELECT something FROM table WHERE IsUniqueidentifier(column) = 1
SQL Server 2012 makes this all much easier with TRY_CONVERT(UNIQUEIDENTIFIER, expression)
SELECT something
FROM your_table
WHERE TRY_CONVERT(UNIQUEIDENTIFIER, your_column) IS NOT NULL;
For prior versions of SQL Server, the existing answers miss a few points that mean they may either not match strings that SQL Server will in fact cast to UNIQUEIDENTIFIER without complaint or may still end up causing invalid cast errors.
SQL Server accepts GUIDs either wrapped in {} or without this.
Additionally it ignores extraneous characters at the end of the string. Both SELECT CAST('{5D944516-98E6-44C5-849F-9C277833C01B}ssssssssss' as uniqueidentifier) and SELECT CAST('5D944516-98E6-44C5-849F-9C277833C01BXXXXXXXXXXXXXXXXXXXXXXXXXXXXX' as uniqueidentifier) succeed for instance.
Under most default collations the LIKE '[a-zA-Z0-9]' will end up matching characters such as À or Ë
Finally if casting rows in a result to uniqueidentifier it is important to put the cast attempt in a case expression as the cast may occur before the rows are filtered by the WHERE.
So (borrowing #r0d30b0y's idea) a slightly more robust version might be
;WITH T(C)
AS (SELECT '5D944516-98E6-44C5-849F-9C277833C01B'
UNION ALL
SELECT '{5D944516-98E6-44C5-849F-9C277833C01B}'
UNION ALL
SELECT '5D944516-98E6-44C5-849F-9C277833C01BXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'
UNION ALL
SELECT '{5D944516-98E6-44C5-849F-9C277833C01B}ssssssssss'
UNION ALL
SELECT 'ÀD944516-98E6-44C5-849F-9C277833C01B'
UNION ALL
SELECT 'fish')
SELECT CASE
WHEN C LIKE expression + '%'
OR C LIKE '{' + expression + '}%' THEN CAST(C AS UNIQUEIDENTIFIER)
END
FROM T
CROSS APPLY (SELECT REPLACE('00000000-0000-0000-0000-000000000000', '0', '[0-9a-fA-F]') COLLATE Latin1_General_BIN) C2(expression)
WHERE C LIKE expression + '%'
OR C LIKE '{' + expression + '}%'
Not mine, found this online... thought i'd share.
SELECT 1 WHERE #StringToCompare LIKE
REPLACE('00000000-0000-0000-0000-000000000000', '0', '[0-9a-fA-F]');
SELECT something
FROM table1
WHERE column1 LIKE '[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]';
UPDATE:
...but I much prefer the approach in the answer by #r0d30b0y:
SELECT something
FROM table1
WHERE column1 LIKE REPLACE('00000000-0000-0000-0000-000000000000', '0', '[0-9a-fA-F]');
I am not aware of anything that you could use "out of the box" - you'll have to write this on your own, I'm afraid.
If you can: try to write this inside a C# library and deploy it into SQL Server as a SQL-CLR assembly - then you could use things like Guid.TryParse() which is certainly much easier to use than anything in T-SQL....
A variant of r0d30b0y answer is to use PATINDEX to find within a string...
PATINDEX('%'+REPLACE('00000000-0000-0000-0000-000000000000', '0', '[0-9a-fA-F]')+'%',#StringToCompare) > 0
Had to use to find Guids within a URL string..
HTH
Dave
Like to keep it simple. A GUID has four - in it even, if is just a string
WHERE column like '%-%-%-%-%'
Though an older post, just a thought for a quick test ...
SELECT [A].[INPUT],
CAST([A].[INPUT] AS [UNIQUEIDENTIFIER])
FROM (
SELECT '5D944516-98E6-44C5-849F-9C277833C01B' Collate Latin1_General_100_BIN AS [INPUT]
UNION ALL
SELECT '{5D944516-98E6-44C5-849F-9C277833C01B}'
UNION ALL
SELECT '5D944516-98E6-44C5-849F-9C277833C01BXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'
UNION ALL
SELECT '{5D944516-98E6-44C5-849F-9C277833C01B}ssssssssss'
UNION ALL
SELECT 'ÀD944516-98E6-44C5-849F-9C277833C01B'
UNION ALL
SELECT 'fish'
) [A]
WHERE PATINDEX('[^0-9A-F-{}]%', [A].[INPUT]) = 0
This is a function based on the concept of some earlier comments. This function is very fast.
CREATE FUNCTION [dbo].[IsGuid] (#input varchar(50))
RETURNS bit AS
BEGIN
RETURN
case when #input like '[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]-[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]'
then 1 else 0 end
END
GO
/*
Usage:
select [dbo].[IsGuid]('123') -- Returns 0
select [dbo].[IsGuid]('ebd8aebd-7ea3-439d-a7bc-e009dee0eae0') -- Returns 1
select * from SomeTable where dbo.IsGuid(TableField) = 0 -- Returns table with all non convertable items!
*/
DECLARE #guid_string nvarchar(256) = 'ACE79678-61D1-46E6-93EC-893AD559CC78'
SELECT
CASE WHEN #guid_string LIKE '________-____-____-____-____________'
THEN CONVERT(uniqueidentifier, #guid_string)
ELSE NULL
END
You can write your own UDF. This is a simple approximation to avoid the use of a SQL-CLR assembly.
CREATE FUNCTION dbo.isuniqueidentifier (#ui varchar(50))
RETURNS bit AS
BEGIN
RETURN case when
substring(#ui,9,1)='-' and
substring(#ui,14,1)='-' and
substring(#ui,19,1)='-' and
substring(#ui,24,1)='-' and
len(#ui) = 36 then 1 else 0 end
END
GO
You can then improve it to check if it´s just about HEX values.
I use :
ISNULL(convert(nvarchar(50), userID), 'NULL') = 'NULL'
I had some Test users that were generated with AutoFixture, which uses GUIDs by default for generated fields. My FirstName fields for the users that I need to delete are GUIDs or uniqueidentifiers. That's how I ended up here.
I was able to cobble together some of your answers into this.
SELECT UserId FROM [Membership].[UserInfo] Where TRY_CONVERT(uniqueidentifier, FirstName) is not null
Use RLIKE for MYSQL
SELECT 1 WHERE #StringToCompare
RLIKE REPLACE('00000000-0000-0000-0000-000000000000', '0', '[0-9a-fA-F]');
In a simplest scenario. When you sure that given string can`t contain 4 '-' signs.
SELECT * FROM City WHERE Name LIKE('%-%-%-%-%')
In BigQuery you can use
SELECT *
FROM table
WHERE
REGEXP_CONTAINS(uuid, REPLACE('^00000000-0000-0000-0000-000000000000$', '0', '[0-9a-fA-F]'))