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lines 5-89 of file: xrst/table/log_table.xrst
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{xrst_begin log_table}
{xrst_spell
  datetime
  unix
  unixepoch
}

The Log Table
#############

Discussion
**********
Note that time below is for the GMT Time Zone.

log_id
******
This column has type ``integer`` and is the primary key for this table.
Its initial value is zero, and it increments by one for each row.

message_type
************
This column has type ``text`` and is one of the following values:
``command`` , ``error`` , ``warning`` .

command
=======

#. The *message* for a command is ``begin`` ,
   followed by white space,
   followed by the name of the command.
   If optional arguments follow the command name,
   they are included after the command name and are separated by spaces.
#. The end of every successful command is logged with *message* equal to
   ``end`` followed by the same text as in the corresponding begin.
   If a ``begin`` message does not have a corresponding ``end`` message,
   the command failed.
   (A corresponding end must occur before he next begin command.)

random_seed
===========
If the option table version of :ref:`option_table@random_seed`
is zero, the value of *unix_time* in the log message with
*message_type* = ``'command'`` and with
*message* = ' ``begin`` *command* '
is used as the random seed during the specified *command* .

error
=====
If a fatal error is detected, a message with this type is added to the
log table and dismod_at exists with an non-zero exit code
directly after reporting the error.

warning
=======
This is a warning.
The message was added to the log file and then program execution
continued as if nothing was wrong.

table_name
**********
This column has type ``text`` .
If it is not ``null`` , *message* must be ``error``
and it is the :ref:`input-name` table in which the error occurred.

row_id
******
This column has type ``integer`` .
If it is not ``null`` , *table_name* is not
``null`` and *row_id* is the primary key value in
the specified table where the error occurred.

unix_time
*********
This column has type ``integer`` and is
the return value of the C++ function ``std::time`` ; i.e.,
the number of seconds since January 1, 1970.
You can convert it to GMT with the SQL command

    ``select datetime`` ( ``unix_time`` , ``'unixepoch'`` ) ``from log`` ;

message
*******
This column has type ``text`` and is the message.

{xrst_end log_table}