Changes

A less safe way to add records to a table is to provide only the values. Whilst this approach works it is vital that the values be specified in the ''exact order'' in which the columns were specified when the table was created. Getting the wrong order will, at the very least result in a an error message (if the data types do not match the columns) and at the worst result in data going into the wrong columns. The other danger of this approach is that the statement may work based on the current table layout but will cause problems should the layout be altered at a later date. With these warnings in mind, here is an example of specifying just the values:

A particularly useful SQL statement involves combining the INPUT and SELECT statements. In this scenario, the SELECT statement reads the values (typically from another table) to be added to the current table. This approach is known as ''INSERT SELECT''. and can be used to perform tasks such as added adding all the rows from one table to another table with the same column layout. The following example uses a ''SELECT'' statement to retrieve the rows in a table called ''old_products'' and adds them to a table called ''new_products'':

The INSERT statement places a relatively high load on the database server. In fact a high volume of insertions can have an adverse effect on other transactions (such as reading data). To reduce the load imposed by a data insertion , consider using the ''LOW_PRIORITY'' keyword. For example: