I am trying to do comparison operators on my postgresql data.
I have a range of data like this
MockTable
ID | IDName | Hours | Minutes |
43 John 30 100
37 Jane 20 92
1 Don 100 22
Each of the fields on the top are labeled in the SQL server as text.
I am trying to pull information like this.
Select *
From "MockTable"
WHERE "HOURS">'25';
Thus recieving the 1st and 3rd column back. However I am not getting this results. Input?
When you compare numbers as strings, you have to think about alphabetical order. The magnitude of the number is meaningless, at this point is merely a word. So "25" is greater than "100" because the "2" comes after the "1" in an alphabetical sense.
What you need to do is either cast your "Hours" field as integer or fix that damned table because numbers in string fields is nasty.
Select * From "MockTable" WHERE CAST("Hours" as INTEGER) > 25;
Obviously, you are going to run into some difficult problems if there are records where the "Hours" field contains non-numeric characters, so you'll have to deal with that if and when it arises.
If your column names are not all-lowercase, you must specify them in double quotes and with the exact same capitalization as they are in the table:
SELECT * FROM "MockTable" WHERE "Hours" > 25;
Note this says "Hours" instead of "HOURS".
For this reason, it’s best to use all-lowercase for your column and table names. In addition, when using lowercase you won’t need to put the double-quotes around the column names unless they are a reserved word that might mean something else in that context.
Related
I have a table in postgres database where I need to find all the rows -
Between two dates where fromTo is date column.
And also only those rows where column data contains mix of lower and upper case letters. for eg: eCTiWkAohbQAlmHHAemK
I can do between two dates as shown below but confuse on second point on how to do that?
SELECT * FROM test where fromTo BETWEEN '2022-09-08' AND '2022-09-23';
Data type for fromTo column is shown below -
fromTo | timestamp without time zone | | not null | CURRENT_TIMESTAMP
You can use a regular expression to check that it is only alphabetical characters and at least one uppercase character.
select *
from foo
where data ~ '[[:upper:]]' and data ~ '^[[:alpha:]]+$';
and fromTo BETWEEN '2022-09-08' AND '2022-09-23'
The character classes will match all alphabetical characters, including those with accents.
Demonstration.
Note that this may not be able to make use of an index. If your table is large, you may need to reconsider how you're storing the data.
I am trying to do a query in SQLite3 to order a column by numerical value. Instead of getting the rows ordered by the numerical value of the column, the rows are ordered alphabetically by the first digit's numerical value.
For example in the query below 110 appears before 2 because the first digit (1) is less than two. However the entire number 110 is greater than 2 and I need that to appear after 2.
sqlite> SELECT digit,text FROM test ORDER BY digit;
1|one
110|One Hundred Ten
2|TWO
3|Three
sqlite>
Is there a way to make 110 appear after 2?
It seems like digit is a stored as a string, not as a number. You need to convert it to a number to get the proper ordering. A simple approach uses:
SELECT digit, text
FROM test
ORDER BY digit + 0
I'm looking to select the primary key of a row and I've only got a column that contains info (in a substring) that I need to select the row.
E.g. MyTable
ID | Label
------------
11 | 1593:#:#:RE: test
12 | 1239#:#:#some more random text
13 | 12415#:#:#some more random text about the weather
14 | 369#:#:#some more random text about the StackOverflow
The label column has always a delimiter of :#:#:
So really I guess, I'd need to be able to split this row by the delimiter, grab the first part of the label column (i.e. the number I'm looking) to get the id I wanted.
So, If I wanted row with ID of 14, then I'd be:
Select ID from MyTable
where *something* = '369'
Any ideas on how to construct something ..or how best to go about this:)
I'm completely stumped and haven't been able to find how to do this.
Thanks,
How about:
WHERE label LIKE '369#%'?
No reason to get fancy.
Although.. if you are going to do this search often, then maybe pre-split that value out to another column as part of your ETL process and index it.
Is it possible to execute a LIKE statement against a table column that contains DECIMAL types? Or else, what would be the best way to select matching rows given a number in a decimal (or integer) field?
E.g.:
Name Age
... ...
John 25
Mary 76
Jim 45
Erica 34
Anna 56
Bob 55
Executing something like SELECT * FROM table WHERE age LIKE 5 would return:
Name Age
John 25
Jim 45
Anna 56
Bob 55
It is not clear from your question what exactly you are trying to achieve, but based on the example query, the filtering you need to do should be achievable using normal arithmetic operators.
SELECT * FROM table WHERE MOD(age, 10) = 5 -- All records where the age ends in 5
Or:
SELECT * FROM table WHERE MOD(age, 5) = 0 -- All records where age is divisible by 5
Now that you clarified that though you are using a DECIMAL field you are not actually using it as a numeric value (as if you would, the requirement wouldn't exist), the answers given by others are reasonable - convert the field to a text value and use LIKE on it.
Alternatively, change the type of the field to something that is more suitable to the way you are using it.
You can convert your decimal field to varchar and then apply like.
If you create a query
select name from table where age like '%5%'
you could achieve this (at least in mysql and db2)
But if you prefer to match a number you should use something like:
select name from table where age > minimum and age < maximum
Or try to compare against a modulo if you are really interested in querying on the last number.
I have a database table of my own that I am trying to construct a query for that seems simple enough, but I feel like I am messing up somewhere because the results are not what they should be.
I basically have a table that is like the following:
Table: Data
Columns:
Row ID Profile Import ID Field ID Product
1 5 Null 5 60 Can
2 0 Null 5 65 Hat
3 0 Null 5 70 Box
4 6 Null 6 60 Fish
I basically want to take the word "Hat" in row 2 and place it into the "Profile" column of row 1, replacing the null value there. I am doing this for multiple rows.
In the case of the multiple rows I want to take the "Profile" column and make it equal to the "Product" column. I only want this to happen in the rows where the "ID" value matches the "Import ID", and where the "Field ID" is 65 specifically. In the example above the "ID" 5 matches the "Import ID" 5, so I want to take the "Product" value "Hat" where the "Field ID" is 65, and place that value into the "Profile" column where the ID is 5. My table has over 9000 rows and 600 would have to be changed in this way, with various ID's needing various products inserted.
The result I would like would be:
Row ID Profile Import ID Field ID Product
1 5 Hat 5 60 Can
2 0 Null 5 65 Hat
3 0 Null 5 70 Box
4 6 Null 6 60 Fish
I pray that makes sense...
My query was this
UPDATE 'Data'
SET 'Profile'='Product'
WHERE 'ID'='Import ID' AND 'Field ID'=65;
I have also tried a subquery
UPDATE 'Data'
SET 'Profile'= (SELECT 'Product' FROM Data WHERE 'Field ID'=65)
WHERE 'ID'='Import ID';
This did not work and I am just wondering if there is some logic I missing. Thank you to anyone who can help, I have been up for a bit trying to understand this...
You need to join the data; something like:
UPDATE d1
SET d1.Profile = d2.Product
FROM [Data] d1 -- dest
INNER JOIN [DATA] d2 -- source
ON d2.[Import ID] = d1.[ID] AND d2.[Field ID] = 65
(note swapped 2 columns...)
A couple thing to keep in mind when learning sql:
it isnt a good idea to have spaces in column names. although they might be easier to read, it makes your queries more difficult. most databases dont allow them at all, and those that do have different ways to specify the columns in queries.
to work around your problem, perhaps you should try to enclose the column name in backticks (`), or in square brackets ([ ]).
in any case, instead of a space, please consider an underscore.
with that in mind you should also remember that not to put column names in quotes. something like
SELECT 'Product' FROM Data WHERE 'Field ID'=65
would not work for two reasons:
a. Selecting quoted text will return that quoted text. so were the where clause to return two rows, you would get the text 'Product' returned twice.
b. here your where clause is comparing the text 'Field ID' with the number 65, which would always be false.
hope that helps