Chapter 21. Debugging MySQL Applications

MySQL client programs produce diagnostic messages when they encounter problems. These messages help you to determine the causes of these problems so that you can correct them. This chapter discusses how to use diagnostic output produced by MySQL. It covers the following exam topics:

• Interpreting error messages

• Using the SHOW WARNINGS and SHOW ERRORS statements

• Using the perror utility program

Other sources of diagnostic information are the error log and the slow query log. Log files are likely to be available only to database administrators, so use of the logs for diagnostic purposes is covered in the DBA section of this study guide, in Chapter 40, "Interpreting Diagnostic Messages."