Inserting data into a temporary table

Question

After having created a temporary table and declaring the data types like so;

CREATE TABLE #TempTable(
ID int,
Date datetime,
Name char(20))

H

Answer 1

insert into #temptable (col1, col2, col3)
select col1, col2, col3 from othertable

Note that this is considered poor practice:

insert into #temptable 
select col1, col2, col3 from othertable

If the definition of the temp table were to change, the code could fail at runtime.

Answer 2

My way of Insert in SQL Server. Also I usually check if a temporary table exists.

IF OBJECT_ID('tempdb..#MyTable') IS NOT NULL DROP Table #MyTable

SELECT b.Val as 'bVals'
  INTO #MyTable
FROM OtherTable as b

Answer 3

INSERT INTO #TempTable(ID, Date, Name)
SELECT OtherID, OtherDate, OtherName FROM PhysicalTable

Answer 4

Basic operation of Temporary table is given below, modify and use as per your requirements,

-- CREATE A TEMP TABLE

CREATE TABLE #MyTempEmployeeTable(tempUserID  varchar(MAX), tempUserName  varchar(MAX) )

-- INSERT VALUE INTO A TEMP TABLE

INSERT INTO #MyTempEmployeeTable(tempUserID,tempUserName) SELECT userid,username FROM users where userid =21

-- QUERY A TEMP TABLE [This will work only in same session/Instance, not in other user session instance]

SELECT * FROM #MyTempEmployeeTable

-- DELETE VALUE IN TEMP TABLE

DELETE FROM #MyTempEmployeeTable

-- DROP A TEMP TABLE

DROP TABLE #MyTempEmployeeTable

Answer 5

I have provided two approaches to solve the same issue,

Solution 1: This approach includes 2 steps, first create a temporary table with specified data type, next insert the value from the existing data table.

CREATE TABLE #TempStudent(tempID  int, tempName  varchar(MAX) )
INSERT INTO #TempStudent(tempID, tempName) SELECT id, studName FROM students where id =1

SELECT * FROM #TempStudent

Solution 2: This approach is simple, where you can directly insert the values to temporary table, where automatically the system take care of creating the temp table with the same data type of original table.

SELECT id, studName  INTO #TempStudent FROM students where id =1

SELECT * FROM #TempStudent

Answer 6

SELECT  ID , Date , Name into #temp from [TableName]