1.10 Issuing Queries
1.10.1 Problem
You've
started mysql and now you want to send queries to
the MySQL server.
1.10.2 Solution
Just type them in, but be sure to let mysql know
where each one ends.
1.10.3 Discussion
To issue a query at the mysql> prompt, type it
in, add a semicolon ( ;) at the end
to signify the end of the statement, and press Return. An explicit
statement terminator is
necessary; mysql doesn't
interpret Return as a terminator because it's
allowable to enter a statement using multiple input lines. The
semicolon is the most common terminator, but you can also use
\g
("go") as a synonym for the
semicolon. Thus, the following examples are equivalent ways of
issuing the same query, even though they are entered differently and
terminated differently:
mysql> SELECT NOW( );
+---------------------+
| NOW( ) |
+---------------------+
| 2001-07-04 10:27:23 |
+---------------------+
mysql> SELECT
-> NOW( )\g
+---------------------+
| NOW( ) |
+---------------------+
| 2001-07-04 10:27:28 |
+---------------------+
Notice for the second query that the prompt changes from
mysql> to
-> on the second
input line. mysql changes the prompt this way to
let you know that it's still waiting to see the
query terminator.
Be sure to understand that neither the ; character
nor the \g sequence that serve as query
terminators are part of the query itself. They're
conventions used by the mysql program, which
recognizes these terminators and strips them from the input before
sending the query to the MySQL server. It's
important to remember this when you write your own programs that send
queries to the server (as we'll begin to do in the
next chapter). In that context, you don't include
any terminator characters; the end of the query string itself
signifies the end of the query. In fact, adding a terminator may well
cause the query to fail with an error.
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