Updating a table from another table
In the diagram below you’ll see where there is a match between these two tables: By matching esql Sales Person. Notice here we’re constructing a full name from the views First Name and Last Name columns. So, once we have the join, the last bit of business to it do the update. Suppose the Sales Last Year figures were found to be incorrect and needed to be adjusted by five percent.
Full Name to v Sales Person we can update esql Sales Person. Before we go much further, let’s first wipe out the city column values. You can easily adjust the values using the following statement: However, suppose the sales department want a record of all changes.
DEFAULT Specifies that the default value defined for the column is to replace the existing value in the column.
This can also be used to change the column to NULL if the column has no default and is defined to allow null values.
This “all or nothing” behavior can be modified for arithmetic errors. An exclusive (X) lock is always placed on a table when an update is run.
Common table expressions can also be used with the SELECT, INSERT, DELETE, and CREATE VIEW statements.
Some of the common ones are: In these cases, the UPDATE statement execution stops and the UPDATE generates an error.
No rows from the UPDATE statement are saved into the table, even those rows that didn’t generate an error.
When SET ANSI_PADDING OFF then CHAR data types are padded with spaces, VARCHAR data types have trailing spaces removed, and VARBINARY have trailing zeros removed.
For instance, if a field is defined as CHAR(10) and you update the value ‘Kris’ into this column, then it will be padded with six spaces.