I am using PostgreSQL, and I have a column in a table which contains very long text. I want to select this column in a query, but limit its display length.
Something like:
select longcolumn (only 10 chars) from mytable;
How would I do this?
What you can do is use PostgreSQL's substring() method. Either one of the two commands below will work:
SELECT substring(longcolumn for 10) FROM mytable;
SELECT substring(longcolumn from 1 for 10) FROM mytable;
Slightly shorter:
SELECT left(longcolumn, 10) from mytable;
Related
I my DB i want to select data which having A15-A19 using LIKE operator but couldnt get required result.
the code i made as SELECT * FROM MASTER_RULE WHERE VALUE BETWEEN LIKE 'A15%' AND 'A19%' and also tried regular expression as SELECT * FROM MASTER_RULE WHERE REGEXP_LIKE(value, 'A[1-9]') . But regexp gives all records not specified range 15-19.
How to achieve the solution for this?
Your first query is not ok, it has one extra keyword that you do not need.
Here is the regexp_like solution:
SELECT * FROM MASTER_RULE WHERE REGEXP_LIKE(value, '^A[1][5-9]')
Here is a demo
UPDATE:
Here is the "BETWEEN SOLUTION":
SELECT *
FROM MASTER_RULE
WHERE substr(value, 2,length(value)-1) between 15 AND 19
You could just use regular string comparisons:
where value >= 'A15' and
value < 'A20'
Not only is this simple, but the code can also take advantage of an index on value.
As you mentioned in the comments your data is like A15, A16, A17. etc you can achive your requirement with simple in clause also.
SELECT * FROM MASTER_RULE WHERE VALUE in ('A15','A16','A17','A18,'A19');
I have got a table with a column that is type of VARCHAR2(255 BYTE). I would like to select only these rows that have numbers as a value, so I discard any other values as for example "lala","1z". I just want to have pure numbers from 1 to ..... 999999999 (just digital numbers in other words) :P
Could you tell me how to make it?
if you're using Oracle 12c r2 or later then use the built-in validate_conversion() function:
select *
from your_table
where validate_conversion(cast(your_column as number)) = 0
validate_conversion() returns 0 when the proposed conversion would succeed and 1 when it wouldn't. It also supports date and timestamp conversions. Find out more.
Something like this is the usual option. You could use regexp, but it's usually a bit slower.
select column1
from tableA
where translate(column1, '1234567890', '') is null;
Here's the regexp version kfinity referred to. The regex matches a line consisting of 1 or more digits.
select column1
from tableA
where regexp_like(column1, '^\d+$');
You don't want zero to start a number. So it seems like regular expressions are the way to go:
where regexp_like(column1, '^[1-9][0-9]*$');
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 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'm having trouble finding a way to write a query that will return all non-integers in a float column in SQL Server 2005/8.
I have a float field where the majority of the data in it is actually integers, but I'd like to take a look at the rows where the values actually contain a decimal value. The first thing I tried was modulus 1, but the % operator doesn't work on float values.
Thanks for your help!
I don't know exact syntax of MSSQL, however you could try something like that (pseudo-code)
SELECT ... FROM tbl_name WHERE col_name != CAST(col_name AS INTEGER)
are you just wanting the rows with a decimal in it?
select field
from table
where field like '%.%'
Try something like:
SELECT *
FROM MyTable
WHERE (CONVERT(INT, floatField) - floatField) <> 0
You may also try this:
SELECT * FROM tbl WHERE col != ROUND(col)