I guess the correct way of truncating a value in MySQL is truncate(value,limit); but that doesn't seem to be working here it needs an extra table name;
select truncate(94204.27348,2);
ERROR at line1:
ORA-00923: FROM keyword not found where expected
Assuming you are using Oracle, you must supply a table reference on your select query.
Oracle select queries require a table reference always.
You can do this....
Select truncate(94204.27348,2) -- see further comment below
From dual
;
Dual is a special table that allows these sort of queries.
Also, I think you might mean to use the TRUNC function.
As others have pointed out, the TRUNCATE query is not quite the same, it will erase the contents of the table that you supply it.
In Mysql You should use round. Truncating table will remove the data from the table and reset all your auto increment values.
SELECT ROUND(94204.27348,2);
Result - 94204.27
This will round the value and display only two decimal places.
Related
We can write select column1,column2 into #temp from tableName in SQL Server. But I am unable to write the same query in an Oracle database.
I want to store the result of select/insert/delete/update or any result set into a local temporary table in oracle database. How I can do this?
I am executing below query in my Oracle sql developer tool:
select * into #temp
from bmi;
but I am getting the error as follow please help to find this error.
when I execute the same query in Microsoft SQL Server it get executed & #temp table get created which is not present in the database but it can hold the data for that particular session. so i want same scenario in ORACLE database.
ORA-00911: invalid character
00911. 00000 - "invalid character"
*Cause: identifiers may not start with any ASCII character other than
letters and numbers. $#_ are also allowed after the first
character. Identifiers enclosed by doublequotes may contain
any character other than a doublequote. Alternative quotes
(q'#...#') cannot use spaces, tabs, or carriage returns as
delimiters. For all other contexts, consult the SQL Language
Reference Manual.
*Action:
Error at Line: 1 Column: 15
I want to store the result of select/insert/delete/update or any result set into a local temporary table in oracle database,How I can Do This?
You can't. Oracle doesn't have local temporary tables, it doesn't work like that. But it doesn't need to. Oracle has a very different internal model from SQL Server which means a lot of SQL Server practices are unnecessary in Oracle. (To be fair SQL Server has neat things which Oracle doesn't, like ANSI 92 Joins for DML.)
The key insight is: you don't want to store the result of select/insert/delete/update or any result set into a local temporary table. That is something you had to do in T-SQL to achieve the end goal of implementing some business logic. But what you actually wanted to do in SQL Server and what you want to do in Oracle is write some code which delivers value to your organisation.
So, with that mindset in place, what do you need to do?
If you want to loop round a result set then perhaps a Cursor Loop is what you're looking for?
for rec in ( select * from some_table
where the_date = date '2018-02-01' )
loop
...
If you want to work on some data prior to inserting it into a data then perhaps you should use a PL/SQL collection:
type l_recs is table of some_table%rowtype;
But maybe you just need to understand Oracle's Transaction Management model. A lot of things are possible in pure SQL without any need for procedural framework.
Create temporary table :
create global temporary table
results_temp (column1, column2)
on commit preserve rows;
and then insert to it from your table:
insert into results_temp (column1, column2 )
SELECT column1,column2
FROM source_table
create global temporary table temp_table_name
on commit preserve rows as select column1,column2,columnN from your_table;
Such a query as in the title would look like this I guess:
select * from table t where (t.k1='apple' and t.k2='pie') or (t.k1='strawberry' and t.k2='shortcake')
... --10000 more key pairs here
This looks quite verbose to me. Any better alternatives? (Currently using SQLite, might use MYSQL/Oracle.)
You can use for example this on Oracle, i assume that if you use regular concatenate() instead of Oracle's || on other DB, it would work too (as it is simply just a string comparison with the IN list). Note that such query might have suboptimal execution plan.
SELECT *
FROM
TABLE t
WHERE
t.k1||','||t.k2 IN ('apple,pie',
'strawberry,shortcake' );
But if you have your value list stored in other table, Oracle supports also the format below.
SELECT *
FROM
TABLE t
WHERE (t.k1,t.k2) IN ( SELECT x.k1, x.k2 FROM x );
Don't be afraid of verbose syntax. Concatenation tricks can easily mess up the selectivity estimates or even prevent the database from using indexes.
Here is another syntax that may or may not work in your database.
select *
from table t
where (k1, k2) in(
('apple', 'pie')
,('strawberry', 'shortcake')
,('banana', 'split')
,('raspberry', 'vodka')
,('melon', 'shot')
);
A final comment is that if you find yourself wanting to submit 1000 values as filters you should most likely look for a different approach all together :)
select * from table t
where (t.k1+':'+t.k2)
in ('strawberry:shortcake','apple:pie','banana:split','etc:etc')
This will work in most of the cases as it concatenate and finds in as one column
off-course you need to choose a proper separator which will never come in the value of k1 and k2.
for e.g. if k1 and k2 are of type int you can take any character as separator
SELECT * FROM tableName t
WHERE t.k1=( CASE WHEN t.k2=VALUE THEN someValue
WHEN t.k2=otherVALUE THEN someotherValue END)
- SQL FIDDLE
I made a mistake and entered:
SELECT * FROM table LIMIT1
instead of
SELECT * FROM table LIMIT 1 (note the space between LIMIT and 1)
in the CLI of MySQL. I expected to receive some kind of parse error, but I was surprised, because the query returned all of the records in the table. My first thought was "stupid MySQL, I bet that this will return error in PostgreSQL", but PostgreSQL also returned all records. Then tested it with SQLite - with the same result.
After some digging, I realized that it doesn't matter what I enter after the table. As long as there are no WHERE/ORDER/GROUP clauses:
SELECT * FROM table SOMETHING -- works and returns all records in table
SELECT * FROM table WHERE true SOMETHING -- doesn't work - returns parse error
I guess that this is a standardized behavior, but I couldn't find any explanation why's that. Any ideas?
Your first query is equivalent to this query using a table alias:
SELECT * FROM yourtable AS LIMIT1
The AS keyword is optional. The table alias allows you to refer to columns of that table using the alias LIMIT1.foo rather than the original table name. It can be useful to use aliases if you wish to give tables a shorter or a more descriptive alias within a query. It is necessary to use aliases if you join a table to itself.
From the SQL lite documentation:
This is why I want DB engine to force the usage of keyword AS for alias names
http://beyondrelational.com/modules/2/blogs/70/posts/10814/should-alias-names-be-preceded-by-as.aspx
SELECT * FROM table LIMIT1;
LIMIT1 This has taken as alias by SQL, cause LIMIT1 is not a reserved literal of SQL.
Something after table name and that is not a reserved keyword always taken as an table alias by SQL.
SELECT * FROM table LIMIT 1;
When you used LIMIT just after the table name, SQL found that as a reserved keyword and worked for it as per the behavior. IF you want to use reserved key words in query It can be done by putting reserved literals in quotes. like..
SELECT * FROM table `LIMIT`;
OR
SELECT * FROM table `LIMIT 1`;
Now all words covered under `` quotes will treated as user defined.
Commonly we did mistake with date, timestamp, limit etc.. keywords by using them as column names.
what kind of SQL is this?
SELECT IFNULL(SUM(prenotazione.VALUTAZIONE),0) AS somma,
COUNT(*) AS numero
FROM `prenotazione`
WHERE prenotazione.USER_ID=18793 AND
prenotazione.PRENOTAZIONE_STATO_ID IN (10,11)
I'm using propel as my ORM.
Any way to convert that kind of SQL to Mysql SQL?
This query is valid in MySQL. It selects all rows from the prenotazione table where the user_id is 18793 and the prenotazione_stato_id is 10 or 11. The resulting rows are summarized: in the numero column you get the number of rows found, in the somma column you get the sum of the valutazione values. If no rows were selected, SUM() would return NULL. To prevent this, IFNULL([expr1],[expr2]) is applied, which returns [expr1] if it is not null, and [expr2] if it is null. This makes sure you always return a number.
There is no easy way to do this with Propel, since your result cannot be easily mapped to a Propel object. The best thing you can do is use the underlying database layer (PDO) to escape your parameters and handle the resultset, and you don't open an extra database connection or something like that.
When considering portability, Standard SQL is your friend. This query can be very easily transformed into Standard SQL-92:
Terminate the statement with a semi-colon.
Replace IFNULL with COALESCE.
Remove the single quotes from the table name.
With better spacing it could look like this:
SELECT COALESCE(SUM(prenotazione.VALUTAZIONE), 0) AS somma,
COUNT(*) AS numero
FROM prenotazione
WHERE prenotazione.USER_ID = 18793
AND prenotazione.PRENOTAZIONE_STATO_ID IN (10,11);
That said, for MySQL you probably would need to undo step 3... which leads me to suspect it was MySQL syntax in the first place.
Using Babelfish to give a rough translation from Italian to English results in
SELECT IFNULL(SUM(reservation.APPRAISAL),0) AS sum,
COUNT(*) AS number
FROM `reservation`
WHERE reservation.USER_ID=18793 AND
reservation.RESERVATION_STATE_ID IN (10,11)
Share and enjoy.
I know you cannot use a alias column in the where clause for T-SQL; however, has Microsoft provided some kind of workaround for this?
Related Questions:
Unknown Column In Where Clause
Can you use an alias in the WHERE clause in mysql?
“Invalid column name” error on SQL statement from OpenQuery results
One workaround would be to use a derived table.
For example:
select *
from
(
select a + b as aliased_column
from table
) dt
where dt.aliased_column = something.
I hope this helps.
Depending on what you are aliasing, you could turn it into a user defined function and reference that in both places. Otherwise your copying the aliased code in several places, which tends to become very ugly and means updating 3+ spots if you are also ordering on that column.