SQL/MX 2.x Reference Manual (H06.04+)

Introduction

HP NonStop SQL/MX Reference Manual—540440-003

1-4

SQL Comments

You can include comments in MXCI input lines. Comments are useful for describing a

statement or command. You can also use comments to disable specific statements or

commands without removing them from the source code, such as for debugging

purposes.

To indicate that an MXCI line is a comment, precede the comment with two hyphens

(--):

-- comment-text

All text between two hyphens and the end of the physical line is a comment. You can

include a comment within a statement or command (but not within a literal) if you use

more than one physical line to enter the statement or command.

If you include comments in an MXCI command file, MXCI prints the comments along

with the commands as it executes the file.

Examples of SQL Comments

•

Show comments and SQL statements from an MXCI command file—and the

output from the SQL statements—as displayed by MXCI when the file is executed:

-- This example shows a use of the AVG function

SELECT AVG (salary) FROM persnl.employee;

(EXPR)

----------------

49441.52

--- 1 row(s) selected.

-- This example shows a use of the DISTINCT clause.

SELECT AVG (DISTINCT SALARY)

FROM PERSNL.EMPLOYEE;

(EXPR)

----------------

53609.89

--- 1 row(s) selected.