Ms sql view not updating
Check what we have in the “Departments duplicate” table – nine rows and two columns with information. For the sake of this exercise, we will change all the department numbers and names in this table. “Departments Duplicate” is a table now comprising identical rows!
Right before that, we will execute a COMMIT command. Now, if we write the code that updates the “Department Duplicate” table, setting a department number equal to D-0-1-1 and a department name “Quality Control”, and then run it, we will modify all rows of the data table. This would typically happen by mistake – when the WHERE clause and the accompanying conditions have not been added. When executed, it will take us to the last COMMIT that has been run.
One can always make a simple mistake that could result in the loss of a large amount of data. One last thing – to properly switch off the safe updates, reconnection to the database is required. It is used to update the values of existing records in a table.
So, let’s exit this connection and then reconnect, typing the password once again! In the previous post about SQL INSERT Statement, we inserted an employee under the number of 9-9-9-9-0-1, remember? The syntax to adhere to is UPDATE table name, the keyword SET, column names and the respective values assigned to them, and finally – WHERE, and a certain condition, or set of conditions, that must be satisfied.
However, it could also eliminate the possibility of the state of the data in our database.
It will refer to the state corresponding to the time you executed COMMIT.
This means if you have already used COMMIT 10 times, ROLLBACK will have an effect on the last execution you have performed.
This means SQL’s optimizer will, so to speak, access the record with employee number 999901, and substitute the existing values with the new ones indicated in the UPDATE statement.
Note that we did not update the “hire date” column value, right? This is fine, as we do not have to update each value of the record of interest. With a different birthdate and gender, although with the same hire date.