How to create dynamic columns in a temporary table sql

Last Updated: May 19, 2021 | Author: Geraldine-Bass

Can you use a temp table in dynamic SQL?

While you cannot dynamically create a temp table and then use that temp table outside of the scope of the dynamic execution, there is a trick you can do to work around this issue. You can simply create a static temp table and then dynamically change it’s columns. This includes adding and removing columns dynamically.

How do I create a dynamic column in SQL?

Creating a Dynamic Pivot Table – Step-By-Step
  1. Get a list of unique product lines.
  2. Create a column list.
  3. Construct a Pivot Table as SQL Statement.
  4. Execute the statement.

Can you alter a temp table in SQL?

You can ALTER the SQL Server temp tables after creating it, but table variables don’t support any DDL statement like ALTER statement. SQL temp tables can‘t be used in User Defined Functions, but table variables can be.

Should I drop temp table in stored procedure?

No you don’t need to drop temp tables. That notwithstanding, I tend to do a conditional drop at the beginning of a sproc and it has nothing to do with any effect on the spoc. Rather, they are an artifact from development and testing prior to conversion to a stored procedure.

How do I view a temp table in SQL?

The name of a temporary table must start with a hash (#). Now, to see where this table exists; go to “Object Explorer -> Databases -> System Databases-> tempdb -> Temporary Tables”. You will see your temporary table name along with the identifier.

Is CTE a temp table?

This biggest difference is that a CTE can only be used in the current query scope whereas a temporary table or table variable can exist for the entire duration of the session allowing you to perform many different DML operations against them.

Can we create temporary table in stored procedure?

You can create and use temporary tables in a stored procedure, but the temporary table exists only for the duration of the stored procedure that creates it. When the procedure completes, Adaptive Server automatically drops the temporary table. A single procedure can: Create a temporary table.

How do I check if a variable exists in a table?

So, there’s as much sense in talking about a table variable’s existence as in talking about the existence of any variable: if you have declared the thing in your source code, it exists starting from that point until the end of its scope, which, in SQL Server, is known to be either the batch or the stored procedure/

Which is the correct way to declare a table variable?

If we want to declare a table variable, we have to start the DECLARE statement which is similar to local variables. The name of the local variable must start with at(@) sign. The TABLE keyword specifies that this variable is a table variable.

What is difference between temp and table variable?

A Temp table is easy to create and back up data. Table variable involves the effort when you usually create the normal tables. Table variable will store in the physical memory for some of the data, then later when the size increases it will be moved to the tempdb.

What is faster a table variable or temporary table?

Whereas, a Temporary table (#temp) is created in the tempdb database. So table variable is faster then temporary table. ⇒ Temporary tables are allowed CREATE INDEXes whereas, Table variables aren’t allowed CREATE INDEX instead they can have index by using Primary Key or Unique Constraint.

Is CTE better than temp table?

It is a temporary result set and typically it may be a result of complex sub-query. Unlike the temporary table, its life is limited to the current query. It is defined by using WITH statement. CTE improves readability and ease in maintenance of complex queries and sub-queries.

Can you have a foreign key on a temp table?

Yes, a table can have more than one foreign key. You can even have multiple columns in the same child table referring to the same parent table.

How do you create a temp table?

The Syntax to create a Temporary Table is given below:
  1. To Create Temporary Table: CREATE TABLE #EmpDetails (id INT, name VARCHAR(25))
  2. To Insert Values Into Temporary Table: INSERT INTO #EmpDetails VALUES (01, ‘Lalit’), (02, ‘Atharva’)
  3. To Select Values from Temporary Table: SELECT * FROM #EmpDetails.
  4. Result: id. name. Lalit.

Can we use temp table in function?

You cannot use #table in function freely because functions (UDF) can contain only calls to deterministic “things” as could stay deterministic themselves. Select to temp table is not deterministic because table doesn’t have to exists.

What is a temporary table?

Temporary Tables. A temporary table is a base table that is not stored in the database, but instead exists only while the database session in which it was created is active. A temporary table exists for the entire database session in which it was created.

What is the difference between view and temporary table?

The main difference between temporary tables and views is that temporary tables are just the tables in tempdb, but views are just stored queries for existing data in existing tables. So, there is no need to populate the view, because the data is already here.

What is temporary table in MySQL?

In MySQL, a temporary table is a special type of table that allows you to store a temporary result set, which you can reuse several times in a single session. A temporary table is very handy when it is impossible or expensive to query data that requires a single SELECT statement with the JOIN clauses.

How do you create a temp table and insert data in SQL?

Syntax
  1. — Create Local temporary table.
  2. Create Table #myTable (id Int , Name nvarchar(20))
  3. —Insert data into Temporary Tables.
  4. Insert into #myTable Values (1,’Saurabh’);
  5. Insert into #myTable Values (2,’Darshan’);
  6. Insert into #myTable Values (3,’Smiten’);
  7. — Select Data from the Temporary Tables.
  8. Select * from #myTable.

How do I create a temp table in SP?

Example 1: Temporary tables in SQL Editor.

* Open SQL editor and execute following queries. INSERT INTO MY_GLOBAL_TEMP_TABLE VALUES (3,’C’); INSERT INTO MY_GLOBAL_TEMP_TABLE VALUES (4,’D’); * This will create one local temporary table and one global temporary table.

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