how to count number of tables/views/index in my database
I am using sybase 11
select count(*) from sysobjects where type = 'U'
should get you the number of user tables. You can also use type = 'V' to count views.
select count(*) from sysindexes
will give you an index count. You may need to further filter both though, depending on which types of indexes you want.
sysobjects reference here.
sysindexes reference here.
For oracle
Count Tables:
SELECT COUNT(*) FROM user_tables;
Count Sequences
SELECT COUNT(*) FROM user_sequences;
Count Views
SELECT COUNT(*) FROM user_views;
Count Indexes
SELECT COUNT(*) FROM user_indexes;
Hi Hope this below sql works
SELECT COUNT(*) FROM USER_TABLES;
will return you number of tables in respective database.
Related
I am developing a report against a SQL Server database. Using the query presented here...
SELECT
f.FacilityID as 'FID',
COUNT (DISTINCT f.PhoneTypeID) as 'Ptypes',
COUNT (DISTINCT f.PhoneID) as 'Pnumbers'
from dbo.FacilityPhones as f
inner join
dbo.Phones as ph
f.PhoneID = ph.PhoneID
group by f.FacilityID
having COUNT(DISTINCT f.PhoneTypeID)<>COUNT(DISTINCT f.PhoneId);
...I have identified 107 records where the number of phone numbers present for a Facility differs from the number of phone number types (e.g., there are two distinct phone numbers, both listed as primary).
I would like to be able to produce a detailed report that would list phone numbers and phone types for each facility, but ONLY when the distinct counts differ.
Is there a way to do this with a single query? Or would I need to save the summaries to a temp table, then join back to that temp table to get the details?
Not sure what fields exist in dbo.Phone; but assume the number comes from there... Likely need to join to the type table to get it's description as well...
This uses a common table expression to get your base list of items an then a correlated subquery to ensure only those facilities in your cte are displayed.
WITH CTE AS (
SELECT f.FacilityID as 'FID'
, COUNT (DISTINCT f.PhoneTypeID) as 'Ptypes'
, COUNT (DISTINCT f.PhoneID) as 'Pnumbers'
FROM dbo.FacilityPhones as f
GROUP BY f.FacilityID
HAVING COUNT(DISTINCT f.PhoneTypeID)<>COUNT(DISTINCT f.PhoneId))
SELECT *
FROM dbo.FaclityPhones FP
INNER JOIN dbo.Phones as ph
ON FP.PhoneID = ph.PhoneID
WHERE EXISTS (SELECT 1
FROM CTE
WHERE FID = FP.FacilityID)
The where clause here just says only show those FacilityID's and associated records if the FacilityID exists in your original query (CTE) (107) If we needed data from the CTE we'd join to it; but as it's simply restricting data placing it in the where clause and using an exists will likely be more efficient.
I am trying to retrieve data from a very large Audits table (millions of rows). So I need to make the query run as efficiently as possible.
First I am playing with a subquery to return the ObjectTypeId and use this to limit the query on the Audit table
This query is taking 4 minutes to run:
select distinct Audits.ObjectTypeID, COUNT(*) as Count
from Audits as Audits
where Audits.ObjectTypeID =
(select distinct ObjectType.ObjectTypeID from ObjectType where ObjectName = 'Data')
group by Audits.ObjectTypeID
If I default in the ObjectTypeID the query runs in 42 seconds
select distinct(Audits.ObjectTypeID), COUNT(*) as Count
from Audits
where Audits.ObjectTypeID = 1
group by Audits.ObjectTypeID
But the subquery when run in isolation only takes only a second to run. So why should the first query take so long?
I can see three things that might help:
Pull the ObjectTypeID into a variable: since there should be only one value for it
Take out the DISTINCT on both queries since they should be unnecessary (the subquery should only have one value and you are grouping by that value in the outer query
Take out the GROUP BY since you are only querying for one ObjectTypeID
So the final query would be:
DECLARE #ObjectTypeID INT
SELECT #ObjectTypeID = (select ObjectType.ObjectTypeID
from ObjectType
where ObjectName = 'Data')
select Audits.ObjectTypeID, COUNT(*) as Count
from Audits as Audits
where Audits.ObjectTypeID = #ObjectTypeID
If you are executing this as a single statement and not as a batch or stored procedure (meaning you can't use variables) thne you can keep the subquery:
select Audits.ObjectTypeID, COUNT(*) as Count
from Audits as Audits
where Audits.ObjectTypeID =
(select ObjectType.ObjectTypeID
from ObjectType
where ObjectName = 'Data')
The part where you are getting the most performance hit could be this line:
where Audits.ObjectTypeID =
(select distinct ObjectType.ObjectTypeID from ObjectType where ObjectName = 'Data')
You are actually calling the same query on every row of your table and it will search the ENTIRE ObjectType table and return the ENTIRE result of that subquery. This will be a big performance hit if your ObjectType table is HUGE. You could speed up that section of the query by using EXISTS so that it will return early once a result was found. Here is an example:
SELECT a.ObjectTypeID, COUNT(*) as Count
FROM Audits a
WHERE EXISTS
(
SELECT ot.ObjectTypeID
FROM ObjectType ot
WHERE ot.ObjectName = 'Data' AND ot.ObjectTypeID = a.ObjectTypeID
)
GROUP BY a.ObjectTypeID
Can you try this
SELECT DISTINCT Audits.ObjectTypeID, COUNT(*) as Count
FROM Audits as Audits
INNER JOIN
(SELECT DISTINCT ObjectTypeId, ObjectName FROM ObjectType
WHERE ObjectName = 'Data') as ObjectType ON Audits.ObjectTypeID = ObjectType.ObjectTypeID
GROUP BY Audits.ObjectTypeID
I have about 100 select statements that look like this:
select * from users where clientid='GUID'
select * from providers where clientid='GUID'
They are really simple, but how I can I define the GUID once instead of having to put it into each select statement?
DECLARE #GuidVar VARCHAR(38);
SELECT #GuidVar ='GUID'
select * from users where clientid=#GuidVar
select * from providers where clientid=#GuidVar
use the IN clause and just put a list of comma separated IDs
SELECT * FROM users WHERE clientid IN (guid1,guid2,guid3)
MySQL IN Clause
Not sure if this might help you:
select * from users u
inner join providers p
on p.clientid = u.clientid
where u.clientid = 'GUID'
And you can continue to add inner joins for all tables and join on clientid. You will only require one where clause at the end.
The downside is that you will get all the columns in on row for each table. What you can do is to select specify tables or columns e.g select u.*, p.clientid
I've got the following SQL, but I only want to return rows where 'hits' are greater than 10.
SELECT clicks.affiliate, COUNT(*) AS hits, affiliates.title, affiliates.url
FROM clicks
INNER JOIN affiliates ON affiliates.id = clicks.affiliate
GROUP BY clicks.affiliate
Thanks.
To filter by an aggregate you need to use the having clause. Unlike many RDBMSs MySQL does allow you to use the column alias in this context (Most other RDBMSs would also insist on affiliates.title, affiliates.url being added to the group by clause as well)
SELECT clicks.affiliate, COUNT(*) AS hits, affiliates.title, affiliates.url
FROM clicks
INNER JOIN affiliates ON affiliates.id = clicks.affiliate
GROUP BY clicks.affiliate
HAVING hits > 10
SELECT clicks.affiliate, COUNT(*) AS hits, affiliates.title, affiliates.url
FROM clicks
INNER JOIN affiliates ON affiliates.id = clicks.affiliate
GROUP BY clicks.affiliate
HAVING COUNT(*) > 10
...
HAVING hits > 10
I have the following Query and i need the query to fetch data from SomeTable based on the filter criteria present in the Someothertable. If there is nothing present in SomeOtherTable Query should return me all the data present in SomeTable
SQL SERVER 2005
SomeOtherTable does not have any indexes or any constraint all fields are char(50)
The Following Query work fine for my requirements but it causes performance problems when i have lots of parameters.
Due to some requirement of Client, We have to keep all the Where clause data in SomeOtherTable. depending on subid data will be joined with one of the columns in SomeTable.
For example the Query can can be
SELECT
*
FROM
SomeTable
WHERE
1=1
AND
(
SomeTable.ID in (SELECT DISTINCT ID FROM SomeOtherTable WHERE Name = 'ABC' and subid = 'EF')
OR
0=(SELECT Count(1) FROM SomeOtherTable WHERE spName = 'ABC' and subid = 'EF')
)
AND
(
SomeTable.date =(SELECT date FROM SomeOtherTable WHERE Name = 'ABC' and subid = 'Date')
OR
0=(SELECT Count(1) FROM SomeOtherTable WHERE spName = 'ABC' and subid = 'Date')
)
EDIT----------------------------------------------
I think i might have to explain my problem in detail:
We have developed an ASP.net application that is used to invoke parametrize crystal reports, parameters to the crystal reports are not passed using the default crystal reports method.
In ASP.net application we have created wizards which are used to pass the parameters to the Reports, These parameters are not directly consumed by the crystal report but are consumed by the Query embedded inside the crystal report or the Stored procedure used in the Crystal report.
This is achieved using a table (SomeOtherTable) which holds parameter data as long as report is running after which the data is deleted, as such we can assume that SomeOtherTable has max 2 to 3 rows at any given point of time.
So if we look at the above query initial part of the Query can be assumed as the Report Query and the where clause is used to get the user input from the SomeOtherTable table.
So i don't think it will be useful to create indexes etc (May be i am wrong).
SomeOtherTable does not have any
indexes or any constraint all fields
are char(50)
Well, there's your problem. There's nothing you can do to a query like this which will improve its performance if you create it like this.
You need a proper primary or other candidate key designated on all of your tables. That is to say, you need at least ONE unique index on the table. You can do this by designating one or more fields as the PK, or you can add a UNIQUE constraint or index.
You need to define your fields properly. Does the field store integers? Well then, an INT field may just be a better bet than a CHAR(50).
You can't "optimize" a query that is based on an unsound schema.
Try:
SELECT
*
FROM
SomeTable
LEFT JOIN SomeOtherTable ON SomeTable.ID=SomeOtherTable.ID AND Name = 'ABC'
WHERE
1=1
AND
(
SomeOtherTable.ID IS NOT NULL
OR
0=(SELECT Count(1) FROM SomeOtherTable WHERE spName = 'ABC')
)
also put 'with (nolock)' after each table name to improve performance
The following might speed you up
SELECT *
FROM SomeTable
WHERE
SomeTable.ID in
(SELECT DISTINCT ID FROM SomeOtherTable Where Name = 'ABC')
UNION
SELECT *
FROM SomeTable
Where
NOT EXISTS (Select spName From SomeOtherTable Where spName = 'ABC')
The UNION will effectivly split this into two simpler queries which can be optiomised separately (depends very much on DBMS, table size etc whether this will actually improve performance -- but its always worth a try).
The "EXISTS" key word is more efficient than the "SELECT COUNT(1)" as it will return true as soon as the first row is encountered.
Or check if the value exists in db first
And you can remove the distinct keyword in your query, it is useless here.
if EXISTS (Select spName From SomeOtherTable Where spName = 'ABC')
begin
SELECT *
FROM SomeTable
WHERE
SomeTable.ID in
(SELECT ID FROM SomeOtherTable Where Name = 'ABC')
end
else
begin
SELECT *
FROM SomeTable
end
Aloha
Try
select t.* from SomeTable t
left outer join SomeOtherTable o
on t.id = o.id
where (not exists (select id from SomeOtherTable where spname = 'adbc')
OR spname = 'adbc')
-Edoode
change all your select statements in the where part to inner jons.
the OR conditions should be union all-ed.
also make sure your indexing is ok.
sometimes it pays to have an intermediate table for temp results to which you can join to.
It seems to me that there is no need for the "1=1 AND" in your query. 1=1 will always evaluate to be true, leaving the software to evaluate the next part... why not just skip the 1=1 and evaluate the juicy part?
I am going to stick to my original Query.