I want to take the modulus of a value when using Impala and I am aware of the abs() function. When I use this however like such
select abs(value) from table
It returns a value that is rounded to the nearest integer. The documentation found here states that I need to define the numeric_type. have tried this
select abs(float value) from table
but this gives me the following error
AnalysisException: Syntax error in line 1: ... abs(float value) from table ^ Encountered: FLOAT Expected: ALL, CASE, CAST, DEFAULT, DISTINCT, EXISTS, FALSE, IF, INTERVAL, NOT, NULL, TRUNCATE, TRUE, IDENTIFIER CAUSED BY: Exception: Syntax error
Any ideas how I set abs() to return a float?
This should work SELECT cast(Abs(-243.5) as float) AS AbsNum
I think you are misunderstanding the syntax. You call the function as abs(val). The return type is the same as the input type. It should work on integers, decimals, and floats.
If you want a particular type being returned, then you need to pass in that type, perhaps casting to the specific type.
The documentation is:
abs(numeric_type a)
Purpose: Returns the absolute value of the argument.
Return type: Same as the input value
Admittedly, this does look like the type should be part of the function call. But it is really using a programming language-style declaration to show the types that are expected.
Related
I have a column called "Bakery Activity" whose values are all JSONs that look like this:
{"flavors": [
{"d4js95-1cc5-4asn-asb48-1a781aa83": "chocolate"},
{"dc45n-jnsa9i-83ysg-81d4d7fae": "peanutButter"}],
"degreesToCook": 375,
"ingredients": {
"d4js95-1cc5-4asn-asb48-1a781aa83": [
"1nemw49-b9s88e-4750-bty0-bei8smr1eb",
"98h9nd8-3mo3-baef-2fe682n48d29"]
},
"numOfPiesBaked": 1,
"numberOfSlicesCreated": 6
}
I'm trying to extract the number of pies baked with a regex function in Tableau. Specifically, this one:
REGEXP_EXTRACT([Bakery Activity], '"numOfPiesBaked":"?([^\n,}]*)')
However, when I try to throw this calculated field into my text table, I get an error saying:
ERROR: function regexp_matches(jsonb, unknown) does not exist;
Error while executing the query
Worth noting is that my data source is PostgreSQL, which Tableau regex functions support; not all of my entries have numOfPiesBaked in them; when I run this in a simulator I get the correct extraction (actually, I get "numOfPiesBaked": 1" but removing the field name is a problem for another time).
What might be causing this error?
In short: Wrong data type, wrong function, wrong approach.
REGEXP_EXTRACT is obviously an abstraction layer of your client (Tableau), which is translated to regexp_matches() for Postgres. But that function expects text input. Since there is no assignment cast for jsonb -> text (for good reasons) you have to add an explicit cast to make it work, like:
SELECT regexp_matches("Bakery Activity"::text, '"numOfPiesBaked":"?([^\n,}]*)')
(The second argument can be an untyped string literal, Postgres function type resolution can defer the suitable data type text.)
Modern versions of Postgres also have regexp_match() returning a single row (unlike regexp_matches), which would seem like the better translation.
But regular expressions are the wrong approach to begin with.
Use the simple json/jsonb operator ->>:
SELECT "Bakery Activity"->>'numOfPiesBaked';
Returns '1' in your example.
If you know the value to be a valid integer, you can cast it right away:
SELECT ("Bakery Activity"->>'numOfPiesBaked')::int;
I found an easier way to handle JSONB data in Tableau.
Firstly, make a calculated field from the JSONB field and convert the field to a string by using str([FIELD_name]) command.
Then, on the calculated field, make another calculated field and use function:
REGEXP_EXTRACT([String_Field_Name], '"Key_to_be_extracted":"?([^\n,}]*)')
The required key-value pair will form the second caluculated field.
I am searching for the Float type limitation but I can't find any post for ^ operand.
I have a little mathematical phrase:
((#IntVar*((#FloatVar*1)/1200))*((1+((#FloatVar*1)/1200))^#IntValr))/(((1+((#FloatVar*1)/1200))^#IntVar)-1);
and SQL raises the error:
The data types float and int are incompatible in the ^ operator.
after that, I changed the variable type and new formula is it:
((#IntVar*((#FloatVar*1)/1200))*((1+((#FloatVar*1)/1200))^#FloatValr))/(((1+((#FloatVar*1)/1200))^#FloatVar)-1);
But SQL raises error again:
Operand data type float is invalid for ^ operator.
My first ask is, how to solve this error?
and after that, anybody knows limitation of operands on a float or decimal types?
if you want use exponant function you must use power SQL SERVER function.
look here
I have a column with dates formatted as text, missing values are marked with -.
I try to create an expression (SQL, not VBA) which converts that column to date, converting missing values to 0:
This expression works as expected:
IIf([column]="-",0,CDate([column])
However if I try to make somethin more generic, looking for all non-date inputs I get #Error for all non-date:
IIf(IsError(CDate([column])),0,CDate([column])
What I'm missing here?
I would try and use isDate() as an alternative:
IIf(IsDate([column]),CDate([column],0)
Notice that I have swapped the true and false part around in the iif() as the expression has changed.
Although, if the only alternative to a date is the dash - symbol, which you have used in the first expression I believe that the IsNumeric() function would also work.
In SQL I usually use COALESCE and IFNULL to ensure that I get numbers and not NULL when my queries contain aggregate functions like COUNT and SUM, for example:
SELECT IFNULL(COUNT(foo), 0) AS foo_count FROM …
However, in BigQuery I run into an error:
Argument type mismatch in function IFNULL: 'f0_' is type uint64, '0' is type int32.
Is there a way to make BigQuery understand that a literal 0 should be interpreted as a unit64 in this context?
I've tried using CAST, but there's no unit64 type I can cast to, so I try INTEGER:
SELECT IFNULL(COUNT(foo), CAST(0 AS INTEGER)) AS foo_count FROM …
That gives me basically the same error, but at least I've successfully gotten a 64-bit zero instead of a 32-bit:
Argument type mismatch in function IFNULL: 'f0_' is type uint64, '0' is type int64.
The same happens if I use INTEGER(0).
I can get it to work if I cast both arguments to INTEGER:
SELECT IFNULL(INTEGER(COUNT(foo)), INTEGER(0)) AS foo_count FROM …
But now it starts to be verbose. Is this really how you're supposed to do it in BigQuery?
This is a bug in BigQuery which has been around for quite some time. For the time being you need to force the conversion of the COUNT, but you shouldn't need to do it for your "0".
The following should work:
SELECT IFNULL(INTEGER(COUNT(foo)), 0) AS foo_count FROM
Thanks #Kinaan Khan Sherwani for the link to the official bug report.
In one place I have
CREATE FUNCTION updateGeo2(text, float4, float4) RETURNS float AS $$
followed later by
SELECT updateGeo2('area', 40.88, -90.56);
and I get
error : ERROR: function updategeo2(unknown, numeric, numeric) does not exist
so it doesn't know that I tried to pass in a text variable, followed by a float variable and another float variable, it sees these as "unknown, numeric and numeric", lame. How do I let it know the types I am passing in?
try this way:
SELECT updateGeo2('area', (40.88)::float4, (-90.56)::float4);
Clarify misunderstanding
First of all, this should work as is, without type cast. I tested with PostgreSQL 9.1, 9.2 and also with 8.4.15. You must be running an earlier point-release or there is some other misunderstanding (like wrong search_path). Your information is misleading.
Except for ad-hoc calls, you should always add explicit type casts anyway to disambiguate. PostgreSQL allows function overloading. If another function should be created with the signature:
CREATE FUNCTION updateGeo2(text, numeric, numeric) RETURNS text AS $$ ..
... then it would take precedence over the other one due to the default type numeric for numeric literals. Existing code might break.
If, on the other hand, you add a function:
CREATE FUNCTION updateGeo2(char(5), numeric, numeric) RETURNS text AS $$ ..
Then Postgres does not know what to do any more and throws an exception:
ERROR: function updategeo2(unknown, numeric, numeric) is not unique
Proper syntax
SELECT updateGeo2('area', '40.88'::float4, '-90.56'::float4);
Or, more verbose in standard SQL:
SELECT updateGeo2('area', cast('40.88' AS float4), cast('-90.56' AS float4));
Or, if you really wanted to avoid single quotes (and colons):
SELECT updateGeo2('area', float4 '40.88', float4 '-90.56');
This way you cast a numeric literal to data type float4 (= real) directly.
More about type casting in the manual.
(40.88)::float4 works, too, but subtly less effective. First, 40.88 is taken to be of type numeric (the default type for this numeric literal containing a dot). Then the value is cast to float4. Makes two type casts.
More about numeric constants in the manual.