in mysql we use ` sign before and after column name in query
i want support both oracle and mysql but in oracle ` not support and it most be change to "
is ther anyway to force oracle use ` instead of " for before and after column ?
for example this is my mysql query
SELECT * FROM `md_menu` where `place`='1' AND `adminid`='1' ORDER BY `order` ASC
but it most be change for oracle to this
SELECT * FROM "md_menu" where "place"='1' AND "adminid"='1' ORDER BY "order" ASC
is ther any way?
IMO instead of forcing oracle follow mysql syntax, it will be easier just make mysql follow standard ASCI syntax :
add this line at the top of your mysql syntax, then the identifier change to " for object, ' for string, just like oracle.
SET SESSION sql_mode = 'ANSI';
here is some demonstration :
SET SESSION sql_mode = 'ANSI';
create table "a"
(
id int,
col varchar(1)
);
insert into "a" values (1,'1');
insert into "a" values (2,'2');
select * from "a" where col = '1'
also db<>fidddle.
and I totally agree #P.Salmon mention in comment, avoid using reserved word as object name.
Related
I am using Oracle SQL Developer 4.0.0.13.
Query :
UPDATE employes
SET emptime = systimestamp
WHERE emp_id = 123
AND emp_device = :abc;
Field Definition : emp_device char(20 byte)
Value is : 99998000000008880999 (This value is present in the table)
When I run the above query in SQL developer it asks me to give the value for the bind variable, which I paste in the text box and it returns 0 rows updated.
But when I remove the bind variable in the update query and specify the actual value, it updates the column value. Below is the query.
Query:
UPDATE employes
SET emptime = systimestamp
WHERE emp_id = 123
AND emp_device = 99998000000008880999 ;
---(works)
Also, when I add some trailing spaces in the bind variable text box and trim the emp_device column, it updates the column. Below is the query.
Query :
UPDATE employes
SET emptime = systimestamp
WHERE emp_id = 123
AND emp_device = trim(:abc);
-- (works --- :abc value is '99998000000008880999 ')
I do not know what is wrong with it. Can someone please take a look and suggest a solution.
You are using CHAR type for your emp_device datatype. Note that CHAR type always blank pads the resulting string out to a fixed width.read this.
You should use VARCHAR2 as datatype if you are expecting a string or just NUMBER as your example consists purely of numeric values.
in dialog box enter your parameter as '99998000000008880999' use apostrophe chars.
everybody. I have table, where one of the column names is "All" and I want to get this column. I trying to use next simple query:
SELECT All
FROM TableName
, but I have ORA-00936. When I use just:
SELECT *
FROM TableName
I see required column with "All" name. In table specification I see next SQL script:
create table TableName
(
houseid NUMBER not null,
id NUMBER not null,
note VARCHAR2(255),
all NUMBER
)
How I can get access to "All" column?
SELECT "ALL" from TABLENAME
this is a good reason not to use oracle reserved keywords as table or column names but by using the doublequote " " you can access them.
Keep in mind that when you use " " you must be consistent in your case in the statement. Not "All" and "all" in the same statement
Put it in quotes.
SELECT "all"
FROM TableName
I would like convert the column name to date.
for example the column name is today, i want to convert it dynamically to today's date like MM/DD/YYYY .
as of now the column name is "Today" i want it to be current date
You can't configure a column to change its name automagically. To reflect the current day or whatever else.
But, you can change the column name by using an alias when doing a query. In order to make the things the more transparent as possible, you might want to create a view. Here is an example:
-- Some table with a column named "TODAY"
CREATE TABLE T AS (SELECT LEVEL today FROM DUAL CONNECT BY LEVEL < 5);
-- Use PL/SQL to create a view on the given table
-- with a dynamic column name
DECLARE
today varchar(10) := TO_CHAR(SYSDATE,'DD/MM/YYYY');
query varchar(200) := 'CREATE OR REPLACE VIEW V'
|| ' AS SELECT today "' || today || '"'
|| ' FROM T';
BEGIN
execute immediate query;
END;
Then, to query the "table" with the right column name, you will simply need to query V instead of T:
SELECT * FROM V;
12/12/2014
1
2
3
4
If you recreate your view daily, say by calling the above PL/SQL code from a job, you will see each day a view with the current date as the column name. But, as the underlying table is left unchanged, you will still be able to query it using the canonical name today. Which is important for example if you need to perform join on that table.
That being said, I'm not sure I will push toward such a solution. Use at your own risks!
If you want the column name heading to appear as something different than what the column name is defined in the table, you simply use the as "DisplayColumnName" clause for that column:
select user_name, today as "12/12/2014" from some_table;
But you would need to programatically generate the SQL statement for that to work. What coding environment you are using would dictate how to dynamically create a select statement.
I have a table in oracle db which has a unique index composed of two columns (id and valid_from). The column valid_from is of type timestamps with time zone.
When I query the SYS.USER_IND_COLUMNS to see which columns my table is using as unique index, I can not see the name of the valid_from column but instead I see smth like SYS_NC00027$.
Is there any possibility that I can display the name valid_from rather than SYS_NC00027$. ?
Apparently Oracle creates a function based index for timestamp with time zone columns.
The definition of them can be found in the view ALL_IND_EXPRESSIONS
Something like this should get you started:
select ic.index_name,
ic.column_name,
ie.column_expression
from all_ind_columns ic
left join all_ind_expressions ie
on ie.index_owner = ic.index_owner
and ie.index_name = ic.index_name
and ie.column_position = ic.column_position
where ic.table_name = 'FOO';
Unfortunately column_expression is a (deprecated) LONG column and cannot easily be used in a coalesce() or nvl() function.
Use the below to verify the col info.
select column_name,virtual_column,hidden_column,data_default from user_tab_cols where table_name='EMP';
I need to search rows entered on a specific date.
However the datatype of column I need to search on is datetime, and the datatype of argument is Date.
I can use the the query like
Select result
from table
where
convert(date, Mycolumn) = #selectedDate
but this would affect the SARGability of the query and will not use indexes created on mycolumn.
I was trying to use the following query:
Select result
from table
where
Mycolumn
BETWEEN #selectedDate AND Dateadd(s, -1, Dateadd(D, 1, #selectedDate))
However this does not work since the #selectedDate is Date type and a second can't be added or removed.
Can someone help me with a working query?
Thanks.
It is my understanding that using:
convert(date, Mycolumn) = #selectedDate
is SARGable. It will use the index on Mycolumn (if one exists). This can easily be confirmed by using the execution plan.
Select result
from table
where
Mycolumn >= #selectedDate
AND Mycolumn < Dateadd(D, 1, #selectedDate)
If you need to do these searches a lot, you could add a computed, persisted column that does the conversion to DATE, put an index on it and then search on that column
ALTER TABLE dbo.YourTable
ADD DateOnly AS CAST(MyColumn AS DATE) PERSISTED
Since it's persisted, it's (re-)calculated only when the MyColumn value changes, e.g. it's not a "hidden" call to a stored function. Since it's persisted, it can also be indexed and used just like any other regular column:
CREATE NONCLUSTERED INDEX IX01_YourTable_DateOnly ON dbo.YourTable(DateOnly)
and then do:
SELECT result FROM dbo.YourTable WHERE DateOnly = #SelectedDate
Since that additional info is stored in the table, you'll be using a bit more storage - so you're doing the classic "space vs. speed" trade-off; you need a bit more space, but you get more speed out of it.