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:[2]
[2] Example queries in this book are shown with SQL keywords like SELECT in uppercase for distinctiveness, but that's simply a typographical convention. You can enter keywords in any lettercase.
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.
Using the mysql Client Program
Writing MySQL-Based Programs
Record Selection Techniques
Working with Strings
Working with Dates and Times
Sorting Query Results
Generating Summaries
Modifying Tables with ALTER TABLE
Obtaining and Using Metadata
Importing and Exporting Data
Generating and Using Sequences
Using Multiple Tables
Statistical Techniques
Handling Duplicates
Performing Transactions
Introduction to MySQL on the Web
Incorporating Query Resultsinto Web Pages
Processing Web Input with MySQL
Using MySQL-Based Web Session Management
Appendix A. Obtaining MySQL Software
Appendix B. JSP and Tomcat Primer
Appendix C. References