I'm trying to change a column type from "character varying(15)" to an integer.
If I run "=#SELECT columnX from tableY limit(10);" I get back:
columnX
----------
34.00
12.00
7.75
18.50
4.00
11.25
18.00
16.50
If i run "=#\d+ columnX" i get back:
Column | Type | Modifiers | Storage | Description
columnX | character varying(15) | not null | extended |
I've searched high and low, asked on the postgresql irc channel, but no one could figure out how to change it, I've tried:
ALTER TABLE race_horserecord ALTER COLUMN win_odds TYPE integer USING (win_odds::integer);
Also:
ALTER TABLE tableY ALTER COLUMN columnX TYPE integer USING (trim("columnX")::integer);
Every time I get back:
"ERROR: invalid input syntax for integer: "34.00""
Any help would be appreciated.
Try USING (win_odds::numeric::integer).
Note that it will round your fractional values (e.g., '7.75'::numeric::integer = 8).
Related
In a dataset I have, there is a columns contains numbers like 83.420, 43.317, 149.317, ... and this columns is stored as string. The dot in the numbers doesn't represent decimal point, i.e., the number 83.420 is basically 83420 etc.
One way to remove this dot from numbers in this column is to use TRANSLATE function as follows:
SELECT translate('83.420', '.', '')
which returns 83420. But how I can apply this function on all the rows in the dataset?
I tried this, however, I failed:
SELECT translate(SELECT num_column FROM my_table, '.', '')
I face with error SQL Error [42601]: ERROR: syntax error at end of input.
Any idea how I can apply translate function on one column in data entirely? or any better idea to use rather than translate?
You can even cast the result to numeric like this:
SELECT translate(num_column, '.', '')::integer from the_table;
-- average:
SELECT avg(translate(num_column, '.', '')::integer from the_table;
or use replace
SELECT replace(num_column, '.', '')::integer from the_table;
-- average:
SELECT avg(replace(num_column, '.', '')::integer) from the_table;
Please note that storing numbers as formatted text is a (very) bad idea. Use a native numeric type instead.
Two options.
Set up table:
create table string_conv(id integer, num_column varchar);
insert into string_conv values (1, 83.420), (2, 43.317), (3, 149.317 );
select * from string_conv ;
id | num_column
----+------------
1 | 83.420
2 | 43.317
3 | 149.317
First option leave as string field:
update string_conv set num_column = translate(num_column, '.', '');
select * from string_conv ;
id | num_column
----+------------
1 | 83420
2 | 43317
3 | 149317
The above changes the value format in place. I means though that if new data comes in with the old format, 'XX.XXX', then those values would have to be converted.
Second option convert to integer column:
truncate string_conv ;
insert into string_conv values (1, 83.420), (2, 43.317), (3, 149.317 );
alter table string_conv alter COLUMN num_column type integer using translate(num_column, '.', '')::int;
select * from string_conv ;
id | num_column
----+------------
1 | 83420
2 | 43317
3 | 149317
\d string_conv
Table "public.string_conv"
Column | Type | Collation | Nullable | Default
------------+---------+-----------+----------+---------
id | integer | | |
num_column | integer | | |
This option changes the format of the values and changes the type of the column they are being stored in. The issue is here is that from then on new values would need to be compatible with the new type. This would mean changing the input data from 'XX.XXX' to 'XXXXX'.
We have an existing column(type- double precision) in our postgres table and we want to convert the data type of that column to numeric, we've tried the below approaches but all of them had truncation/data loss on the last decimal positions.
directly converting to numeric
converting to numeric with precision and scale
converting to text and then to numeric
converting to text only
The data loss I mentioned looks like this for eg: if we have a value 23.291400909423828, then after altering the column datatype that value is converted to 23.2914009094238 resulting in loss of the last 2 decimal places.
note: This is happening only if the value has more than 13 decimals(values right to the decimal point)
One way to possibly do this:
show extra_float_digits ;
extra_float_digits
--------------------
3
create table float_numeric(number_fld float8);
insert into float_numeric values (21.291400909423828), (23.291400909422436);
select * from float_numeric ;
number_fld
--------------------
21.291400909423828
23.291400909422435
alter table float_numeric alter COLUMN number_fld type numeric using number_fld::text::numeric;
\d float_numeric
Table "public.float_numeric"
Column | Type | Collation | Nullable | Default
------------+---------+-----------+----------+---------
number_fld | numeric | | |
select * from float_numeric ;
number_fld
--------------------
21.291400909423828
23.291400909422435
I have a column in a Postgresql table that is unique and character varying(10) type. The table contains old alpha-numeric values that I need to keep. Every time a new row is created from this point forward, I want it to be numeric only. I would like to get the max numeric-only value from this table for this column then create a new row with that max value incremented by 1.
Is there a way to query this table for the max numeric value only for this column?
For example, if this column currently has the values:
1111
A1111A
1234
1234A
3331
B3332
C-3333
33-D33
3**333*
Is there a query that will return 3333, AKA cut out all the non-numeric characters from the values and then perform a MAX() on them?
Not precisely what you asking, but something that I think will work better for you.
To go over all the columns, convert each to numbers, and then cast it to integer & return max.:
SELECT MAX(regexp_replace(my_column, '[^0-9]', '', 'g')::int) FROM public.foobar;
This gets you your max value... say 2999.
Now, going forward, consider making the default for your column a serial-like value, and convert it to text... that way you set the "MAX" once, and then let postgres do all the work for future values.
-- create simple integer sequence
CREATE SEQUENCE public.foobar_my_column_seq
INCREMENT 1
MINVALUE 1
MAXVALUE 9223372036854775807
START 1
CACHE 0;
-- use new sequence as default value for column __and__ convert to text
ALTER TABLE foobar
ALTER COLUMN my_column
SET DEFAULT nextval('publc.foobar_my_column_seq'::regclass)::text;
-- initialize "next value" of sequence to whatever is larger than
-- what you already have in your data ... say 3000:
ALTER SEQUENCE public.foobar_my_column_seq RESTART WITH 3000;
Because you're simply setting default, you don't change your current alpha-numeric values.
I figured it out. The following query works.
select text_value, regexp_replace(text_value, '[^0-9]+', '') as new_value from the_table;
Result:
text_value | new_value
-----------------------+-------------
4*215474 | 4215474
740024 | 740024
4*100535 | 4100535
42356 | 42356
CASH |
4*215474 | 4215474
740025 | 740025
740026 | 740026
4*5089655798 | 45089655798
4*15680 | 415680
4*224034 | 4224034
4*265718708 | 4265718708
I have a column that I want to get an average of, the column is varchar(200). I keep getting this error. How do I convert the column to numeric and get an average of it.
Values in the column look like
16,000.00
15,000.00
16,000.00 etc
When I execute
select CAST((COALESCE( bonus,'0')) AS numeric)
from tableone
... I get
ERROR: invalid input syntax for type numeric:
The standard way to represent (as text) a numeric in SQL is something like:
16000.00
15000.00
16000.00
So, your commas in the text are hurting you.
The most sensible way to solve this problem would be to store the data just as a numeric instead of using a string (text, varchar, character) type, as already suggested by a_horse_with_no_name.
However, assuming this is done for a good reason, such as you inherited a design you cannot change, one possibility is to get rid of all the characters which are not a (minus sign, digit, period) before casting to numeric:
Let's assume this is your input data
CREATE TABLE tableone
(
bonus text
) ;
INSERT INTO tableone(bonus)
VALUES
('16,000.00'),
('15,000.00'),
('16,000.00'),
('something strange 25'),
('why do you actually use a "text" column if you could just define it as numeric(15,0)?'),
(NULL) ;
You can remove all the straneous chars with a regexp_replace and the proper regular expression ([^-0-9.]), and do it globally:
SELECT
CAST(
COALESCE(
NULLIF(
regexp_replace(bonus, '[^-0-9.]+', '', 'g'),
''),
'0')
AS numeric)
FROM
tableone ;
| coalesce |
| -------: |
| 16000.00 |
| 15000.00 |
| 16000.00 |
| 25 |
| 150 |
| 0 |
See what happens to the 15,0 (this may NOT be what you want).
Check everything at dbfiddle here
I'm going to go out on a limb and say that it might be because you have Empty strings rather than nulls in your column; this would result in the error you are seeing. Try wrapping the column name in a nullif:
SELECT CAST(coalesce(NULLIF(bonus, ''), '0') AS integer) as new_field
But I would really question your schema that you have numeric values stored in a varchar column...
Sorry for the basic question.
I have a table with the following columns.
Column | Type | Modifiers
--------+---------+-----------
id | integer |
doc_id | bigint |
text | text |
I am trying to do text matching on the 'text' (3rd column)
I receive an error message when I try to text match on the text column. Saying that the string is too long for ts_vector.
I only want observations which contain the words "other events"
SELECT * FROM eightks\d
WHERE to_tsvector(text) ## to_tsquery('other_events')
I know that there are limitation to the length of the ts_vector.
Error Message
ERROR: string is too long for tsvector (2368732 bytes, max 1048575 bytes)
How do I convert the text column into a ts_vector and will this resolve my size limit problem?Alternatively, How do I exclude observations over the maximum size?
Postgres version 9.3.5.0
Here is the reference to the limit limit
Thanks