manual.texi typos

Some of the examples use the table @code{shop} to hold the price of each

article (item number) for certain traders (dealers).  Supposing that each

trader has a single fixed price per article, then (@code{item},

@code{trader}) is a primary key for the records.

trader has a single fixed price per article, then (@code{article},

@code{dealer}) is a primary key for the records.

Start the command line tool @code{mysql} and select a database:

@subsection Using user variables

You can use MySQL user variables to remember results without

having to store them in a temporary variables in the client.

having to store them in temporary variables in the client.

@xref{Variables}.

For example, to find the articles with the highest and lowest price you