Database Values
Each column in the database accepts a fixed type of data. The currently defined basic types, and their representations, are:
true
or false
, respectively.
true
and false
and strings that match
the syntax of UUIDs (see below) must be enclosed in double quotes to
distinguish them from other basic types. When double quotes are used,
the syntax is that of strings in JSON, e.g. backslashes may be used to
escape special characters. The empty string must be represented as a
pair of double quotes (""
).
f81d4fae-7dec-11d0-a765-00a0c91e6bf6
, or an @
name
defined by a get
or create
command within the same ovn-nbctl
invocation.
Multiple values in a single column may be separated by spaces or a
single comma. When multiple values are present, duplicates are not
allowed, and order is not important. Conversely, some database
columns can have an empty set of values, represented as []
, and
square brackets may optionally enclose other non-empty sets or single
values as well.
A few database columns are ``maps'' of key-value pairs, where the key
and the value are each some fixed database type. These are specified
in the form key=
value, where key and value
follow the syntax for the column's key type and value type,
respectively. When multiple pairs are present (separated by spaces or
a comma), duplicate keys are not allowed, and again the order is not
important. Duplicate values are allowed. An empty map is represented
as {}
. Curly braces may optionally enclose non-empty maps as
well (but use quotes to prevent the shell from expanding
other-config={0=x,1=y}
into other-config=0=x
other-config=1=y
, which may not have the desired effect).
Database Command Syntax
--if-exists
] [--columns=
column[,
column]...] list
table [record]...Lists the data in each specified record. If no records are specified, lists all the records in table.
If --columns
is specified, only the requested columns are
listed, in the specified order. Otherwise, all columns are listed, in
alphabetical order by column name.
Without --if-exists
, it is an error if any specified
record does not exist. With --if-exists
, the command
ignores any record that does not exist, without producing any
output.
--columns=
column[,
column]...] find
table [column[:
key]=
value]...
Lists the data in each record in table whose column equals
value or, if key is specified, whose column contains
a key with the specified value. The following operators
may be used where =
is written in the syntax summary:
= != < > <= >=
Selects records in which column[:
key] equals, does not
equal, is less than, is greater than, is less than or equal to, or is
greater than or equal to value, respectively.
Consider column[:
key] and value as sets of
elements. Identical sets are considered equal. Otherwise, if the
sets have different numbers of elements, then the set with more
elements is considered to be larger. Otherwise, consider a element
from each set pairwise, in increasing order within each set. The
first pair that differs determines the result. (For a column that
contains key-value pairs, first all the keys are compared, and values
are considered only if the two sets contain identical keys.)
{=} {!=}
{<=}
:
key] is a subset of
value. For example, flood-vlans{<=}1,2
selects records in
which the flood-vlans
column is the empty set or contains 1 or 2
or both.
{<}
:
key] is a proper
subset of value. For example, flood-vlans{<}1,2
selects
records in which the flood-vlans
column is the empty set or
contains 1 or 2 but not both.
{>=} {>}
{<=}
and {<}
, respectively, except that the
relationship is reversed. For example, flood-vlans{>=}1,2
selects records in which the flood-vlans
column contains both 1
and 2.
For arithmetic operators (= != < > <= >=
), when key is
specified but a particular record's column does not contain
key, the record is always omitted from the results. Thus, the
condition other-config:mtu!=1500
matches records that have a
mtu
key whose value is not 1500, but not those that lack an
mtu
key.
For the set operators, when key is specified but a particular
record's column does not contain key, the comparison is
done against an empty set. Thus, the condition
other-config:mtu{!=}1500
matches records that have a mtu
key whose value is not 1500 and those that lack an mtu
key.
Don't forget to escape <
or >
from interpretation by the
shell.
If --columns
is specified, only the requested columns are
listed, in the specified order. Otherwise all columns are listed, in
alphabetical order by column name.
The UUIDs shown for rows created in the same ovn-nbctl
invocation will be wrong.
--if-exists
] [--id=@
name] get
table record [column[:
key]]...Prints the value of each specified column in the given record in table. For map columns, a key may optionally be specified, in which case the value associated with key in the column is printed, instead of the entire map.
Without --if-exists
, it is an error if record does not
exist or key is specified, if key does not exist in
record. With --if-exists
, a missing record
yields no output and a missing key prints a blank line.
If @
name is specified, then the UUID for record may be
referred to by that name later in the same ovn-nbctl
invocation in contexts where a UUID is expected.
Both --id
and the column arguments are optional, but
usually at least one or the other should be specified. If both are
omitted, then get
has no effect except to verify that
record exists in table.
--id
and --if-exists
cannot be used together.
--if-exists
] set
table record column[:
key]=
value...Sets the value of each specified column in the given record in table to value. For map columns, a key may optionally be specified, in which case the value associated with key in that column is changed (or added, if none exists), instead of the entire map.
Without --if-exists
, it is an error if record does not
exist. With --if-exists
, this command does nothing if
record does not exist.
--if-exists
] add
table record column [key=
]value...
Adds the specified value or key-value pair to column in
record in table. If column is a map, then key
is required, otherwise it is prohibited. If key already exists
in a map column, then the current value is not replaced (use the
set
command to replace an existing value).
Without --if-exists
, it is an error if record does not
exist. With --if-exists
, this command does nothing if
record does not exist.
[--if-exists
] remove
table record column value...
[--if-exists
] remove
table record column key...
[--if-exists
] remov
table record column key=
value...
Removes the specified values or key-value pairs from column in record in table. The first form applies to columns that are not maps: each specified value is removed from the column. The second and third forms apply to map columns: if only a key is specified, then any key-value pair with the given key is removed, regardless of its value; if a value is given then a pair is removed only if both key and value match.
It is not an error if the column does not contain the specified key or value or pair.
Without --if-exists
, it is an error if record does not
exist. With --if-exists
, this command does nothing if
record does not exist.
--if-exists
] clear
table record column...Sets each column in record in table to the empty set or empty map, as appropriate. This command applies only to columns that are allowed to be empty.
Without --if-exists
, it is an error if record does not
exist. With --if-exists
, this command does nothing if
record does not exist.
--id=@
name] create
table column[:
key]=
value...Creates a new record in table and sets the initial values of each column. Columns not explicitly set will receive their default values. Outputs the UUID of the new row.
If @
name is specified, then the UUID for the new row may be
referred to by that name elsewhere in the same \*(PN
invocation in contexts where a UUID is expected. Such references may
precede or follow the create
command.
Open_vSwitch
table. Except for records in the QoS
or Queue
tables,
records that are not reachable from the Open_vSwitch
table are
automatically deleted from the database. This deletion happens
immediately, without waiting for additional ovs-vsctl
commands
or other database activity. Thus, a create
command must
generally be accompanied by additional commands within the same
ovs-vsctl
invocation to add a chain of references to the
newly created record from the top-level Open_vSwitch
record.
The EXAMPLES
section gives some examples that show how to do
this.
--if-exists
] destroy
table record...--if-exists
is specified, each records must exist.
--all destroy
tableDeletes all records from the table.
destroy
command is only useful for records in the QoS
or Queue
tables. Records in other tables are automatically
deleted from the database when they become unreachable from the
Open_vSwitch
table. This means that deleting the last reference
to a record is sufficient for deleting the record itself. For records
in these tables, destroy
is silently ignored. See the
EXAMPLES
section below for more information.
wait-until
table record [column[:
key]=
value]...
Waits until table contains a record named record whose
column equals value or, if key is specified, whose
column contains a key with the specified value. Any
of the operators !=
, <
, >
, <=
, or >=
may
be substituted for =
to test for inequality, less than, greater
than, less than or equal to, or greater than or equal to,
respectively. (Don't forget to escape <
or >
from
interpretation by the shell.)
If no column[:
key]=
value arguments are given,
this command waits only until record exists. If more than one
such argument is given, the command waits until all of them are
satisfied.
wait-until
should be placed at the beginning of a set
of ovs-vsctl
commands. For example, wait-until bridge br0
-- get bridge br0 datapath_id
waits until a bridge named
br0
is created, then prints its datapath_id
column,
whereas get bridge br0 datapath_id -- wait-until bridge br0
will abort if no bridge named br0
exists when ovs-vsctl
initially connects to the database.
Consider specifying --timeout=0
along with
--wait-until
, to prevent ovn-nbctl
from terminating
after waiting only at most 5 seconds.
comment
[arg]...This command has no effect on behavior, but any database log record created by the command will include the command and its arguments.