Appendix D. SQL Syntax Reference

This appendix describes each of the SQL statements provided by MySQL. The syntax for writing comments in SQL code is also described. Comments are used to write descriptive text that is ignored by the server and to hide MySQL-specific keywords (these keywords will be executed by MySQL but ignored by other database servers). See the section "Comment Syntax."

MySQL development is ongoing, so enhancements to its SQL implementation are made on a regular basis. You will find it useful to consult the online MySQL Reference Manual occasionally to see what new capabilities are being added. The manual is available at http://www.mysql.com/.

The syntax descriptions use the following conventions:

• Optional information is enclosed in square brackets ([]). If a list is enclosed in square brackets, one alternative may be chosen.

• If a list is enclosed in curly brackets ({}), one alternative must be chosen.

• Vertical bars (|) separate alternative items in a list.

• Ellipsis notation (…) indicates that the term preceding the ellipsis may be repeated.

Unless otherwise indicated, the statements listed here have been present in MySQL at least as far back as MySQL 3.22.0.