Any column that is not modified retains its original values, except in certain queries using the CASE expression. See CASE expression for a description of CASE expressions. To add, drop, or modify a ...

If you only want to update values in table A when there are matching records in table B, then an inner join is the way to go. If you have calculations that need to vary based on optional data, the ...

Structured query language Structured Query Language is also known as SQL. It is used to create queries that interrogate the data held in a relational database. Examples are: ...