Comments

This document describes the comment syntax supported by MatrixOne.

MatrixOne supports three comment styles:

  • Use # character to comment a line.
  1. mysql> select 100-99; # This comment continues to the end of line
  2. +----------+
  3. | 100 - 99 |
  4. +----------+
  5. | 1 |
  6. +----------+
  7. 1 row in set (0.01 sec)
  • Use -- to comment a line. The -- (double-dash) comment style requires the second dash to be followed by at least one whitespace or control character (such as a space, tab, newline, and so on).
  1. mysql> select 100-99; -- This comment continues to the end of line
  2. +----------+
  3. | 100 - 99 |
  4. +----------+
  5. | 1 |
  6. +----------+
  7. 1 row in set (0.01 sec)
  • From a /* sequence to the following */ sequence, as in the C programming language. This syntax enables a comment to extend over multiple lines because the beginning and closing sequences need not be on the same line.
  1. mysql> select 100 /* this is an in-line comment */ -99;
  2. +----------+
  3. | 100 - 99 |
  4. +----------+
  5. | 1 |
  6. +----------+
  7. 1 row in set (0.01 sec)

Or:

  1. mysql> select 100
  2. /*
  3. this is an in-line comment
  4. */
  5. -99;
  6. +----------+
  7. | 100 - 99 |
  8. +----------+
  9. | 1 |
  10. +----------+
  11. 1 row in set (0.01 sec)

MySQL-compatible comment syntax

The same as MySQL, MatrixOne supports a variant of C comment style:

  1. mysql> select 100 /*! Specific code */ -99;
  2. +----------+
  3. | 100 - 99 |
  4. +----------+
  5. | 1 |
  6. +----------+
  7. 1 row in set (0.02 sec)

Or:

  1. mysql> select 100 /*!50110 Specific code */ -99;
  2. +----------+
  3. | 100 - 99 |
  4. +----------+
  5. | 1 |
  6. +----------+
  7. 1 row in set (0.02 sec)

MatrixOne specific comment syntax

MatrixOne supports a variant of C comment style:

  1. mysql> select 100-99; // This comment continues to the end of line
  2. +----------+
  3. | 100 - 99 |
  4. +----------+
  5. | 1 |
  6. +----------+
  7. 1 row in set (0.03 sec)

Or:

  1. mysql> // This comment continues to the line
  2. -> select 100-99;
  3. +----------+
  4. | 100 - 99 |
  5. +----------+
  6. | 1 |
  7. +----------+

Constraints

MatrixOne does not support nested comments.