How do I store the select column in a variable? - sql-server

How do I store the select column in a variable?
I tried this, but it throws me an error "Incorrect syntax":
declare #EmpId int
SELECT dbo.Employee.Id as #EmpId FROM dbo.Employee

select #EmpID = ID from dbo.Employee
Or
set #EmpID =(select id from dbo.Employee)
Note that the select query might return more than one value or rows. so you can write a select query that must return one row.
If you would like to add more columns to one variable(MS SQL), there is an option to use table defined variable
DECLARE #sampleTable TABLE(column1 type1)
INSERT INTO #sampleTable
SELECT columnsNumberEqualInsampleTable FROM .. WHERE ..
As table type variable do not exist in Oracle and others, you would have to define it:
DECLARE TYPE type_name IS TABLE OF (column_type | variable%TYPE | table.column%TYPE [NOT NULL] INDEX BY BINARY INTEGER;
-- Then to declare a TABLE variable of this type: variable_name type_name;
-- Assigning values to a TABLE variable: variable_name(n).field_name := 'some text';
-- Where 'n' is the index value

Assuming such a query would return a single row, you could use either
select #EmpId = Id from dbo.Employee
Or
set #EmpId = (select Id from dbo.Employee)

This is how to assign a value to a variable:
SELECT #EmpID = Id
FROM dbo.Employee
However, the above query is returning more than one value. You'll need to add a WHERE clause in order to return a single Id value.

Related

How do I use update multiple rows in a stored procedure

I get batches of inventory items to update and I would like to eliminate calling the stored procedure multiple times and instead call it once with multiple values. I have done similar in oracle with the parameters as an array trick. I would like to do something similar for SQL Server.
I have a comma separated list of Sku
I have a comma separated list of Quantity.
I have a comma separated list of StoreIds.
The standard update is
Update Inventory
set quantity = #Quantity
where sku = #Sku and StoreId = #StoreId;
Table definition
CREATE TABLE Inventory
(
[Sku] NVARCHAR(50) NOT NULL,
[Quantity] DECIMAL NULL DEFAULT 0.0,
[StoreId] INT NOT NULL
}
My bad attempt at doing this
ALTER PROCEDURE UpdateList
(#Sku varchar(max),
#Quantity varchar(max),
#StoreId varchar(max))
AS
BEGIN
DECLARE #n int = 0;
DECLARE #skuTable TABLE = SELECT CONVERT(value) FROM STRING_SPLIT(#Sku, ',');
DECLARE #quantityTable = SELECT CONVERT(value) FROM STRING_SPLIT(#Quantity, ',');
DECLARE #StoreIdTable = SELECT CONVERT(value) FROM STRING_SPLIT(#StoreId , ',');
WHILE #n < #skuTable.Count
BEGIN
UPDATE inventoryItem
SET Quantity = #quantityTable
WHERE Sku = #skuTable AND StoreId = #StoreIdTable;
SELECT #n = #n + 1;
END
END
I am open to using temp tables as parameters instead of comma separated. This is being called from an Entity Framework 6 context object from the front end system.
It's a bad practice to pass tabular values in this way.
Best solution is to pass it as a "user defined table type", if possible,
otherwise, it's better to get JSON/XML parameter
and then you can update your table like this:
--[ Parameters ]--
DECLARE #json AS NVARCHAR(MAX) = '[{"Sku":"A","Quantity":1.4,"StoreId":1},{"Sku":"B","Quantity":2.5,"StoreId":2},{"Sku":"C","Quantity":3.6,"StoreId":3}]';
--[ Bulk Update ]--
UPDATE inventoryItem
SET Quantity = I.Quantity
FROM inventoryItem AS T
JOIN OPENJSON(#json) WITH (Sku NVARCHAR(50), Quantity DECIMAL(5,1),StoreId INT) AS I
ON I.Sku = T.Sku
AND I.StoreId = T.StoreId
It's a bad practice to pass tabular values as varchar columns parameters,
but if you still want to go this way, here is a working code:
--[ Parameters ]--
DECLARE #Sku VARCHAR(max) = 'A,B,C',
#Quantity VARCHAR(max) = '1.4,2.5,3.6',
#StoreId VARCHAR(max) = '1,2,3'
--[ Converting VARCHAR Parameters to Table #Inventory ]--
DROP TABLE IF EXISTS #Sku
SELECT IDENTITY(int, 1,1) AS RowNum,
T.value
INTO #Sku
FROM STRING_SPLIT(#Sku, ',') AS T
DROP TABLE IF EXISTS #Quantity
SELECT IDENTITY(int, 1,1) AS RowNum,
T.value
INTO #Quantity
FROM STRING_SPLIT(#Quantity, ',') AS T
DROP TABLE IF EXISTS #StoreId
SELECT IDENTITY(int, 1,1) AS RowNum,
T.value
INTO #StoreId
FROM STRING_SPLIT(#StoreId, ',') AS T
DROP TABLE IF EXISTS #Inventory
SELECT Sku.value AS Sku,
Quantity.value AS Quantity,
StoreId.value AS StoreId
INTO #Inventory
FROM #Sku AS Sku
JOIN #Quantity AS Quantity ON Quantity.RowNum = Sku.RowNum
JOIN #StoreId AS StoreId ON StoreId.RowNum = Sku.RowNum
--[ Bulk Update ]--
UPDATE inventoryItem
SET Quantity = I.Quantity
FROM inventoryItem AS T
JOIN #Inventory AS I
ON I.Sku = T.Sku
AND I.StoreId = T.StoreId
The above answers are correct for updates and answered my question. But I wanted to add the insert here as I am sure someone will be looking for both. Maybe I will come back an make a new question and answer it myself.
I think the JSON version is best for my issue because I am doing entity framework and serializing an object to JSON is a trivial task. The basic process is to create an inline temp table from the json string. Calling out the objects via a simple dot notation string. I would suggest making the object passed in as simple as possible and preferably one level of properties.
create or alter Procedure bulkInventoryInsert( #json AS NVARCHAR(MAX))
AS
BEGIN
INSERT into inventory
SELECT Sku, Quantity, StoreId FROM
OPENJSON(#json)
WITH(Sku varchar(200) '$.Sku',
Quantity decimal(5,1) '$.Quantity',
StoreId INT '$.StoreId');
END
DECLARE #json AS NVARCHAR(MAX) = '[{"Sku":"A","Quantity":1.4,"StoreId":2},{"Sku":"B","Quantity":2.5,"StoreId":3},{"Sku":"C","Quantity":3.6,"StoreId":2}]';
EXECUTE bulkInventoryInsert #json;
The key part to recognize is this section here:
SELECT Sku, Quantity, StoreId FROM
OPENJSON(#json)
WITH(Sku varchar(200) '$.Sku',
Quantity decimal(5,1) '$.Quantity',
StoreId INT '$.StoreId');
This is creating a temp table with columns that match the table that it will be inserted into. The "WITH" portion specifies the column name, type, and where in the Json string to get the value.
I hope this will help. Maybe when I get time I will do a question and answer for this.

How to store the result of an select statement into a variable in sql server stored procedure

I have a condition like this:
IF #aaa = 'high'
set #bbb = select * from table1
else
set #bbb = select * from table2
I am going to use this variable (#bbb) throughout my stored procedure
is this possible to save a table into a variable?
I tried using temporary table but i am not able to assign it twice.
IF #aaa = 'high'
set #bbb = select * into #temp from table1
else
set #bbb = select * into #temp from table2
it shows #temp is already declared.
No, It is not work like that. You can declare a table variable and insert into inside it.
DECLARE #bbbTable TABLE(
Id int NOT NULL,
SampleColumn varchar(50) NOT NULL
);
insert into #bbbTable (Id,SampleColumn)
select Id,SampleColumn from table1
If the table1 and table2 are completely different tables, you should declare two different table variable;
DECLARE #bbbTable TABLE(
Id int NOT NULL,
SampleColumn varchar(50) NOT NULL
);
DECLARE #aaaTable TABLE(
Id int NOT NULL,
SampleColumn varchar(50) NOT NULL
);
IF #aaa = 'high'
insert into #bbbTable (Id,SampleColumn)
select Id,SampleColumn from table1
else
insert into #aaaTable (Id,SampleColumn)
select Id,SampleColumn from table2
You cant insert into a variable more than 1 value.
you can use Table Variable to reach your answer like this:
DELCARE #TableResult AS TABLE (Column1 INT, Column2 INT)
IF #aaa = 'high'
BEGIN
INSERT INTO #TableResult (Column1,Column2)
SELECT Column1FromTable, Column2FromTable
FROM table1
END
ELSE
BEGIN
INSERT INTO #TableResult (Column1,Column2)
SELECT Column1FromTable, Column2FromTable
FROM table2
END
Of course you can declare more than 2 columns.
You can store only 1 Column/Row to a variable.So you can't say *.
Suppose I want to store the value of Column1 from TableA to a variable, I can use this
SELECT #MyVariable = Column1 FROM TableA
But I Can't Say
SELECT #MyVariable = * FROM TableA
Even if there is only 1 column in the Table TableA.
Also If there is more than 1 record returned by the Select condition, then it will assign the First value to the Variable.
Or What you need is to store the entire Rows, you can Either use a Temporary table or a table variable.
Temporary Table
SELECT * INTO #Temp FROM TableA
Table Variable
DECLARE #MyVarTable TABLE
(
Column1 VARCHAR(50),
Column2 VARCHAR(50)
)
INSERT INTO #MyVarTable
(
Column1 ,
Column2
)
SELECT
Column1 ,
Column2
From MyTable
This Temporary Table and Table variable can be accessed in the same way you access the normal table using SELECT/UPDATE/DELETE Queries. Except :
Temporary tables are created for each session and automatically dropped when the session ends or the Query window is Closed
Table Variables exists only when you execute the Query. So before using the table variable in a query you need to declare the same

SQL Adding Function

I'm trying to write a function that adds values that are selected from two different tables. I need the SUM of one column for a specific id in table 1, added to the SUM of a column for a specific id in table 2.
CREATE FUNCTION dbo.getSum(#id varchar(9)) --Our IDs are strings of length 9
RETURNS integer --I've also tried decimal(x,x) and int
AS
BEGIN
DECLARE #total as integer; -- same here with decimal and int
SELECT #total =
(
(select SUM(Amount)
from table1
where id = #id)
+
(select SUM(amount)
from table2
where id = #id)
);
RETURN #total;
END;
I get several types of errors when I try to create this function, like incorrect syntax near 'integer', Must declare the scalar variable "#total"., and Incorrect syntax near 'END'.
I've tried several variations and looked at several SO questions, but haven't found one that's fixed this issue for me yet. This is on SQL Server.
As previously mentioned the cause of your error is you did not define a datatype for your inbound parameter.
I would suggest a bit of a departure from the current structure. Instead of a scalar function I would use an inline table valued function. Something along these lines.
CREATE FUNCTION dbo.getSum(#id int)
RETURNS table
AS RETURN
SELECT SUM(MyAmount)
from
(
select SUM(Amount) as MyAmount
from table1
where id = #id
UNION ALL
select SUM(amount)
from table2
where id = #id
) x;
Looks like you are missing the parameter type in the function definiton
Try with the following
CREATE FUNCTION dbo.getSum(#id int)
RETURNS integer --I've also tried decimal(x,x)
AS
BEGIN
DECLARE #total as integer; -- same here with decimal
SELECT #total =
(
(select SUM(Amount)
from table1
where id = #id)
+
(select SUM(amount)
from table2
where id = #id)
);
RETURN #total;
END;
I think you need to declare the type of the parameter
CREATE FUNCTION dbo.getSum(#id int)
Your data types should be INT and there are general syntax errors... see below.
CREATE FUNCTION dbo.getSum(#id AS INT) -- Declare your paramater AS (datatype)
RETURNS INT -- No need for AS here, just start your block
BEGIN
DECLARE #total AS INT;
SELECT #total =
(
(select SUM(Amount)
from TableOne
where id = #id)
+
(select SUM(amount)
from TableTwo
where id = #id)
);
RETURN #total;
END;

Assigning Variable and Data-Retreival in two select statements with multiple rows

I understand you cannot combine assigning of variables and data-retrieval in the same select statement. I am using two select statements which will work well when a where clause is used and a single row is returned in the select that assigns the variables. How can I make these selects work together when multiple rows are returned from the select that assigns the variables?
DECLARE #CompanyName NVARCHAR(40)
DECLARE #ContactName NVARCHAR(30)
SELECT #CompanyName = CompanyName,
#ContactName = ContactName
FROM Customers
SELECT #CompanyName,#ContactName
Rather go for a table type variable like below
--Declare the table variable with the columns
declare #tab table (
CompanyName NVARCHAR(40),
ContactName NVARCHAR(30)
);
-- insert into table variable
insert into #tab(CompanyName, ContactName)
SELECT CompanyName, ContactName
FROM Customers
-- select from table variable
SELECT * from #tab;
To use a table variable, here's a really simple example based on yours:
declare #TableVar table (companyname varchar(40), contactname varchar(30))
insert into #TableVar
select companyname, contactname from Customers
Then you can select from your table variable, etc.

Table variable error: Must declare the scalar variable "#temp"

I am trying to achieve:
declare #TEMP table (ID int, Name varchar(max))
insert into #temp SELECT ID, Name FROM Table
SELECT * FROM #TEMP
WHERE #TEMP.ID = 1 <--- ERROR AT #TEMP.ID
But I'm getting the following error:
Must declare the scalar variable "#temp".
What am I doing wrong?
A table alias cannot start with a #. So, give #Temp another alias (or leave out the two-part naming altogether):
SELECT *
FROM #TEMP t
WHERE t.ID = 1;
Also, a single equals sign is traditionally used in SQL for a comparison.
Either use an Allias in the table like T and use T.ID, or use just the column name.
declare #TEMP table (ID int, Name varchar(max))
insert into #temp SELECT ID, Name FROM Table
SELECT * FROM #TEMP
WHERE ID = 1
There is one another method of temp table
create table #TempTable (
ID int,
name varchar(max)
)
insert into #TempTable (ID,name)
Select ID,Name
from Table
SELECT *
FROM #TempTable
WHERE ID = 1
Make Sure You are selecting the right database.
If you bracket the # you can use it directly
declare #TEMP table (ID int, Name varchar(max))
insert into #temp values (1,'one'), (2,'two')
SELECT * FROM #TEMP
WHERE [#TEMP].[ID] = 1
You should use hash (#) tables, That you actually looking for because variables value will remain till that execution only.
e.g. -
declare #TEMP table (ID int, Name varchar(max))
insert into #temp SELECT ID, Name FROM Table
When above two and below two statements execute separately.
SELECT * FROM #TEMP
WHERE #TEMP.ID = 1
The error will show because the value of variable lost when you execute the batch of query second time.
It definitely gives o/p when you run an entire block of code.
The hash table is the best possible option for storing and retrieving the temporary value. It last long till the parent session is alive.
try the following query:
SELECT ID,
Name
INTO #tempTable
FROM Table
SELECT *
FROM #tempTable
WHERE ID = 1
It doesn't need to declare table.
You could stil use #TEMP if you quote the identifier "#TEMP":
declare #TEMP table (ID int, Name varchar(max));
insert into #temp SELECT 1 AS ID, 'a' Name;
SELECT * FROM #TEMP WHERE "#TEMP".ID = 1 ;
db<>fiddle demo
You've declared #TEMP but in your insert statement used #temp. Case sensitive variable names.
Change #temp to #TEMP

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