Not sure if this is possible based on what I've researched online. But just want to check to be sure.
If I have a parameter such as:
declare #Person nvarchar(4000)
set #Person = '1234567'
And I have a table called [People], then can I join the two together?
Something like:
SELECT * FROM [People] t1 JOIN #Person t2 ON (t1.ID = t2.ID)
Is such a thing possible and if so can someone please provide the syntax or an exmaple?
Using this sample data:
CREATE TABLE dbo.People (id int, peopleInfo nvarchar(4000));
INSERT dbo.People VALUES (123, 'joe'), (223, 'sally'), (323, 'Mary');
You can do this:
declare #Person nvarchar(4000) = '323'
SELECT t1.*
FROM dbo.People t1
JOIN (VALUES (#Person)) t2(id) ON t1.ID = t2.ID;
But why not just do this?
SELECT t1.*
FROM dbo.People t1
WHERE t1.id = #Person;
Related
I have a table in my tsql datatable:
CREATE TABLE dbo.Test
(
Col nVarChar (50) null
)
GO
And then I executed query:
Select
c.name As Name, ty.name as Type, c.max_length As MaxLenght, c.precision As Precision, c.scale As Scale, c.is_nullable As IsNullable, *
From
sys.schemas s
inner join sys.tables t on s.schema_id = t.schema_id
inner join sys.columns c on t.object_id = c.object_id
inner join sys.types ty on ty.system_type_id = c.system_type_id
Where
s.name LIKE 'dbo' AND t.name LIKE 'Test'
The question is... Why there are Two Rows?!
Check this:
SELECT ROW_NUMBER() OVER(PARTITION BY system_type_id ORDER BY system_type_id)
, *
FROM sys.types;
Check the first column for values >1...
There are few types mapping to the same system_type_id. Some names are just an alias for something else...
UPDATE
This question addresses the same issue...
Are there any shortcuts for deleting everything in one table that does not exist in the second?
I know I can do this:
DECLARE #Table1 TABLE (ID INT)
DECLARE #Table2 TABLE (ID INT)
INSERT INTO #Table1 VALUES (1),(2),(3),(4)
INSERT INTO #Table2 VALUES (3),(4)
DELETE t1
FROM #Table1 t1
WHERE NOT EXISTS (SELECT 1 FROM #Table2 t2 WHERE t2.ID = t1.ID)
SELECT * FROM #Table1
However, I have over 600 columns, so you can see why I might be reluctant to go that route if there's another way. What I WANT to do would look like this:
DECLARE #Table1 TABLE (ID INT)
DECLARE #Table2 TABLE (ID INT)
INSERT INTO #Table1 VALUES (1),(2),(3),(4)
INSERT INTO #Table2 VALUES (3),(4)
DELETE #Table1
EXCEPT SELECT * FROM #Table2
That EXCEPT has been very handy in dealing with this project I'm working on, but I guess it's limited.
Please use this:
DELETE FROM #Table1 WHERE BINARY_CHECKSUM(*) NOT IN(SELECT BINARY_CHECKSUM(*) FROM #Table2);
But be carefull, if your table contains float data types. In very rare cases wrong checksum may be calculated. But, these cases are rare and random, no problems will remain after second delete iteration.
Sure:
DELETE t1
FROM #Table1 t1
LEFT JOIN #Table2 t2 ON t2.ID = t1.ID
WHERE t2.ID IS NULL
My first answer was about the case, when t1 and t2 tables are the same, and joined corressponding cols, when deciding deletion.
Ok, now about the other situation: your #table1 column [ID] can by joined with any unknown #table2 column. You can solve 600+ cols problem using XML:
DELETE FROM #Table1 WHERE CONVERT(NVARCHAR, [ID]) NOT IN
(
SELECT
[col].[value]('(.)[1]', 'NVARCHAR(MAX)')
FROM
(
SELECT [xml] = (CONVERT(XML, (SELECT * FROM #Table2 FOR XML PATH('t2'))))
) AS [t2]
CROSS APPLY [t2].[xml].[nodes]('t2/*') AS [tab]([col])
);
I want to get the data from second table where the row id is equal to first table?Can any one help me with the syntax or code ?
There are a lot of different ways to do that.
You can use join:
Select t2.*
from tab2 t2
join tab1 t1 on t1.id = t2.id
also you can use in operator
Select *
from tab2 t2
where t2.id in ( select t1.id
from table1 t1
)
or you can use exists operator
Select *
from tab2 t2
where exists
(
selec 1
from table1 t1
where t2.id = t1.id
)
As your question is tagged with iPhone IOS so this may be the query string
NSString *query = [NSString stringWithFormat:#"SELECT * FROM secondTable WHERE rowid = %d",yourRowID];
//where yourRowID is your first table id
But if you're talking about Database syntax then see this link table joining .
I have two tables of records that I need to find all of the matches. The tables are based on different Primary Key identifiers, but the data points are exactly the same. I need a fast query that can show me records that are duplicated from the first table to the second. Here is an example of what I am trying to do:
DECLARE #Table1 TABLE (ID INT, Value INT)
DECLARE #Table2 TABLE (ID INT, Value INT)
INSERT INTO #Table1 VALUES (1, 500)
INSERT INTO #Table1 VALUES (2, 500)
INSERT INTO #Table2 VALUES (3, 500)
INSERT INTO #Table2 VALUES (4, 500)
SELECT MAX(x.T1ID)
,MAX(x.T2ID)
FROM (
SELECT T1ID = t1.ID
,T2ID = 0
,t1.Value
FROM #Table1 t1
UNION ALL
SELECT T1ID = 0
,T2ID = t2.ID
,t2.Value
FROM #Table2 t2
) x
GROUP BY x.Value
HAVING COUNT(*) >= 2
The problem with this code is that it returns record 2 in table 1 correlated to record 4 in table 2. I really need it to return record 1 in table 1 correlated to record 3 in table 2. I tried the following:
SELECT MIN(x.T1ID)
,MIN(x.T2ID)
FROM (
SELECT T1ID = t1.ID
,T2ID = 0
,t1.Value
FROM #Table1 t1
UNION ALL
SELECT T1ID = 0
,T2ID = t2.ID
,t2.Value
FROM #Table2 t2
) x
GROUP BY x.Value
HAVING COUNT(*) >= 2
This code does not work either. It returns 0,0.
Is there a way to return the MIN value greater than 0 for both tables?
Might answer my own question. This seems to work. Are there any reasons why I would not do this?
SELECT MIN(t1.ID)
,MIN(t2.ID)
FROM #Table1 t1
INNER JOIN #Table2 t2 ON t1.Value = t2.Value
GROUP BY t1.Value
If you want to see the records in table1 that have matches in table2 then
select *
from #Table1 T1
where exists (select * from #Table2 T2
where T1.ID=T2.ID
-- you would put the complete join clause that defines a match here
)
I wrote this, and it is wrong syntax, help me fix it, I want 'T' to be an alias of the result of the two inner joins.
select T.id
from table1
inner join table2 on table1.x = table2.y
inner join table3 on table3.z = table1.w as T;
You cannot use aliases to name the "entire" join, you can, however, put aliases on individual tables of the join:
select t1.id
from table1 t1
inner join table2 t2 on t1.x = t2.y
inner join table3 t3 on t3.z = t1.w
In the projection, you will have to use the alias of the table, which defines the id column you are going to select.
You can't directly name the result of a join. One option is to use a subquery:
select T.id
from (
select *
from table1
inner join table2 on table1.x = table2.y
inner join table3 on table3.z = table1.w
) T
Another option is subquery factoring:
with T as (
select *
from table1
inner join table2 on table1.x = table2.y
inner join table3 on table3.z = table1.w
)
select T.id
from T