Updating table with table variable

31-Oct-2018 17:54

This means that the SET clause of the UPDATE statement is evaluated once for every row in the updated table.With the SELECT statement, you can’t assign variables and return an output in the same statement.A common misconception is that this is not the case for table variables so a script demonstrating this is below, it declares a table variable, adds a couple of rows then updates them and deletes them.

Variable assignments, just like column assignments, can be made using the full range of T-SQL expressions that you could apply to regular columns in an UPDATE, allowing you to also write more complex expressions.

You’d be forgiven for asking what happens if there’s more than one row in the output.

The answer is that this variable assignment is performed over and over, once for every row in the output.

Next(); end;end; A DB Table variable gets data from the specified source when you first access the variable in your test. If the source is modified, the variable value will not be updated. Variables.initial DBTable Var; # Assign the new variable's value back to the initial variable # Initial variable value will be updated Project. ' Create a new DB Table variable and assign the value of the initial DB Table variable to it Call Project. Add Variable("new DBTable Var", "DB Table") Set new DBTable Var = Project. Variable By Name("new DBTable Var") Set new DBTable Var = Project. // Create a new DB Table variable and assign the value of the initial DB Table variable to it Project. Add Variable('new DBTable Var', 'DB Table'); new DBTable Var := Project. Variable By Name('new DBTable Var'); new DBTable Var := Project.

# Create a new DB Table variable and assign the initial DB Table variable's value to it Project. Add Variable("new DBTable Var", "DB Table"); new DBTable Var = Project. Variable By Name["new DBTable Var"]; new DBTable Var = Project.

Variable assignments, just like column assignments, can be made using the full range of T-SQL expressions that you could apply to regular columns in an UPDATE, allowing you to also write more complex expressions.You’d be forgiven for asking what happens if there’s more than one row in the output.The answer is that this variable assignment is performed over and over, once for every row in the output. Next(); end;end; A DB Table variable gets data from the specified source when you first access the variable in your test. If the source is modified, the variable value will not be updated. Variables.initial DBTable Var; # Assign the new variable's value back to the initial variable # Initial variable value will be updated Project. ' Create a new DB Table variable and assign the value of the initial DB Table variable to it Call Project. Add Variable("new DBTable Var", "DB Table") Set new DBTable Var = Project. Variable By Name("new DBTable Var") Set new DBTable Var = Project. // Create a new DB Table variable and assign the value of the initial DB Table variable to it Project. Add Variable('new DBTable Var', 'DB Table'); new DBTable Var := Project. Variable By Name('new DBTable Var'); new DBTable Var := Project. # Create a new DB Table variable and assign the initial DB Table variable's value to it Project. Add Variable("new DBTable Var", "DB Table"); new DBTable Var = Project. Variable By Name["new DBTable Var"]; new DBTable Var = Project.Table variable instances of those are different in many respects to the ones discussed below! NB: Within stored routines both types of object can be cached rather than repeatedly creating and dropping new tables.