Updating a record in sql
We can expand the Edit tab from the Main Menu and opt for “Preferences”.On the left-hand side of the window that pops up, choose the “SQL Editor” section.clause; columns not explicitly modified retain their previous values.There are two ways to modify a table using information contained in other tables in the database: using sub-selects, or specifying additional tables in the you should ensure that the join produces at most one output row for each row to be modified.We must be very careful when using COMMIT and ROLLBACK – in other words, when we are changing the state of our data set.Please note that it will be very hard to practice these statements unless we switch off the following feature of Workbench.If you don’t provide a WHERE condition, all rows of the table will be updated.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!
None of these two features will help us here, though.
In other words, a target row shouldn't join to more than one row from the other table(s).
If it does, then only one of the join rows will be used to update the target row, but which one will be used is not readily predictable.
ROLLBACK is a command that can bring the state of the data a step back, but not more than that.
It will refer to the state corresponding to the time you executed COMMIT.