cbq: The Command Line Shell for SQL++
cbq is a comprehensive command line shell for SQL++. It is a powerful, developer friendly tool that enables you to query and update data from Couchbase Server. The cbq shell enables you to perform all the operations that are supported by the Query REST API and more, such as additional scripting functionality.
The cbq shell executable, cbq
, is available in the Couchbase Server installation directory.
The cbq shell interface accepts both shell commands as well as SQL++ commands. All the cbq shell commands start with a back-slash (\). If the command does not start with a back-slash (\), the cbq shell interprets the command as a SQL++ command.
When starting the cbq shell you can provide a set of command line options. If no options are present then it assumes default values for expected options.
The cbq shell commands are case insensitive. However, the command line options are case sensitive. |
The cbq shell enables you to manipulate parameters based on the REST API. See Parameter Manipulation for details.
Running the cbq Shell
To run cbq
on the local host:
-
Log in to a Couchbase Server node that has the query service enabled.
-
Open a command window.
-
Change to the Couchbase tools directory.
-
Linux
-
macOS
-
Microsoft Windows
$ cd /opt/couchbase/bin
$ cd /Applications/Couchbase\ Server.app/Contents/Resources/couchbase-core/bin
> cd C:\Program Files\Couchbase\Server\bin
-
-
Run the following command to connect to the local query node and start the interactive query shell:
-
Linux / macOS
-
Microsoft Windows
$ ./cbq
> cbq
-
Executing a Single Command
You can use the --script
option to execute a single SQL++ query and exit the shell:
$ ./cbq -u Administrator -p password -e "http://localhost:8091" \
--script="SELECT * FROM \`travel-sample\`.inventory.airline LIMIT 1;"
Connected to : http://localhost:8091/. Type Ctrl-D or \QUIT to exit.
Path to history file for the shell : ~/.cbq_history
SELECT * FROM `travel-sample`.inventory.airline LIMIT 1;
{
...
}
Support for Multi-line Queries
The cbq shell supports multi-line queries by default, enabling you to enter a query over multiple lines.
When entering a query, you can hit Enter without specifying a semi-colon (;
) at the end of the line to move the cursor to the next line.
The prompt >
indicates that the shell is in multi-line mode.
For example:
cbq> SELECT *
> FROM `travel-sample`.inventory.airline
> LIMIT 1;
When you’re done, use a semi-colon ;
to indicate the end of the query, and then press Enter to execute the query.
Handling Comments
You can add comments in your query by preceding the comment with a #
or --
.
The cbq shell interprets a line that starts with #
or --
as a comment, logs the line into history, and returns a new prompt.
No other action is taken.
cbq> SELECT *
> #This is the first comment
> FROM `travel-sample`.inventory.airline
> --This is the second comment
> LIMIT 1;
However, if a comment exists within a statement, it is considered as part of the SQL++ command.
If the cbq shell encounters a block comment (enclosed between /*
... */
) within a statement, it sends the block comment to the query service.
cbq> SELECT * FROM `travel-sample`.inventory.airline /* Block comment */ LIMIT 1;
File Based Operations
The cbq shell can execute SQL++ and shell commands contained in files using file-based commands and options. See File Based Operations for more information.
History
The cbq
shell stores the history for every session.
All the commands executed in a session are stored in history.
By default, history is stored in ~/.cbq_history.
You can change the name of the file using the SET command to set the predefined parameter HISTFILE
.
cbq> \SET HISTFILE filename;
By default, all the commands are stored in the specified file. You can scroll through history and retrieve the commands from history using the scrolling arrow keys. Once the query is on the command prompt, you can edit it before executing the updated query.
Exit Status
The cbq shell returns the exit status 0 for successful exit with no errors and 1 if an error was encountered before exiting.
Exit On Error
When you specify the argument --exit-on-error
, the cbq shell checks the result returned after executing the query for any error and exits when the first error is encountered.
Help
Help displays the help information for the shell commands and for the general usage of cbq. Use the help option when bringing up the shell to display the information for all available options:
$ ./cbq -h
$ ./cbq --help
Use the \HELP
shell command during a session to display information for specific shell commands.
If you specify one or more commands, the shell displays the usage information for the specified commands.
cbq> \HELP command-name;
If you do not specify a command, the cbq shell lists all the commands for which syntax help is available.
cbq> \HELP;
Available Command Line Options and Shell Commands
Option | Arguments | Description and Examples |
---|---|---|
|
string (url) |
The connection string consists of a protocol scheme, followed by a host, and optionally a port number to connect to the query service (8093) or the Couchbase cluster (8091). For more details, refer to Connecting to the Cluster or Query Node. Shell command: \CONNECT Default
Examples
Result
|
|
boolean [1] |
When specified, the cbq shell does not connect to any query service. You must explicitly connect to a query service using the \CONNECT shell command. Default
Example
|
|
string ( |
Specifies whether to connect to a node’s principal or alternate address.
Default
Example
|
|
boolean [1] |
When specified, disables the startup connection message for the cbq shell. Default
Example
Result
|
|
boolean [1] |
Runs ADVISE on all queries in the specified file, or that are read from standard input, if a file is not provided with the Default
Example
Result
|
|
boolean [1] |
Only applicable when connecting to the Analytics Service. When specified, if you are connecting to a cluster, cbq automatically discovers and connects to an Analytics node. This option also switches on batch mode. Default
Example
|
|
string ( |
This option is available only with the Analytics Service. When specified, cbq sends the queries to server only when you hit EOF or \ to indicate the end of the batch input. Default
Examples
You can also set the batch mode in the interactive session using the \SET command:
|
|
string (duration) |
Sets the query timeout parameter. Default
Example
|
|
string |
Specifies a single user name to log in to Couchbase.
When used by itself, without the This option requires administration credentials and you cannot switch the credentials during a session. Couchbase recommends using the Default
none Example
Result
Enter Password: |
|
string |
Specifies the password for the given user name. You cannot use this option by itself. It must be used with the -u option to specify the user name. This option requires administration credentials and you cannot switch the credentials during a session. Couchbase recommends using the Default
none Example
|
|
string |
Specify the login credentials in the form of Shell command: \SET REST API: Default
none Example
|
|
boolean [1] |
When specified, provides the version of the cbq shell. To display the query engine version of Couchbase Server (this is not the same as the version of Couchbase Server itself), use one of the following SQL++ queries:
Shell command: \VERSION Default
Example
Result
SHELL VERSION : 2.0 Use {sqlpp} queries select version(); or select min_version(); to display server version. |
|
none |
Provides help for the command line options. Shell command: \HELP Default
none Example
|
|
string |
Provides a single command mode to execute a query from the command line. You can also use multiple Default
none Examples
Result
Path to history file for the shell : ~/.cbq_history \SET v 1 \SET b 2 \PUSH b3 ERROR 139 : Too few input arguments to command. \SET b 5 \SET Query Parameters : Named Parameters : User Defined Session Parameters : Predefined Session Parameters : Parameter name : histfile Value : [".cbq_history"] Parameter name : batch Value : ["off"] Parameter name : quiet Value : [false] Parameter name : v Value : [1] Parameter name : b Value : [5] |
|
string (path) |
Provides an input file which contains all the commands to be run. Shell command: \SOURCE Default
none Example
|
|
string (path) |
Specifies an output file where the commands and their results are to be written. If the file doesn’t exist, it is created. If the file already exists, it is overwritten. Shell command: \REDIRECT Default
none Example
|
boolean [1] |
Specifies whether the output should be formatted with line breaks and indents. This option is set to Default
Example
|
|
boolean [1] |
When specified, the cbq shell must exit when it encounters the first error. Default
Example
|
|
string (path) |
Only applicable when using an encrypted protocol scheme — either https:// or couchbases://. Specifies the path to the root CA certificate to verify the identity of the server. Default
none Example
|
|
string (path) |
Only applicable when using an encrypted protocol scheme — either https:// or couchbases://. Specifies the path to the chain certificate. Default
none Example
|
|
string (path) |
Only applicable when using an encrypted protocol scheme — either https:// or couchbases://. Specifies the path to the client key file. Default
none Examples
|
|
|
boolean [1] |
Only applicable when using an encrypted protocol scheme — either https:// or couchbases://. When specified, the cbq shell can skip the verification of certificates. Default
Examples
|
Shell Command | Arguments | Description and Examples |
---|---|---|
|
Connects cbq shell to the specified query engine or Couchbase cluster. The connection string consists of a protocol scheme, followed by a host, and optionally a port number to connect to the query service (8093) or the Couchbase cluster (8091). For more details, refer to Connecting to the Cluster or Query Node. Examples
|
|
none |
Disconnects the cbq shell from the query service or cluster endpoint. Example
Result
Couchbase query shell not connected to any endpoint. Use \CONNECT command to connect. |
|
|
none |
Exits cbq shell. Examples
|
|
Sets the top most value of the stack for the given variable with the specified value. Variables can be of the following types:
When the Examples
|
|
|
Pushes the specified value on to the given parameter stack. When the While each variable stack grows by 1, the previous values are preserved. Examples
Check variable stack
Result
Query Parameters : Parameter name : args Value : [[6,7] [8] [8]] ... |
|
|
Deletes or resets the entire stack for the specified parameter. Examples
Result
Query Parameters : ... |
|
|
Pops the top most value from the specified parameter’s stack. When the Examples
Result
Query Parameters : Parameter name : args Value : [[6,7] [8]] |
|
|
Creates a command alias for the specified cbq shell command or SQL++ statement.
You can then execute the alias using When the Examples
Result
serverversion select version() travel-limit1 SELECT * FROM `travel-sample`.inventory.airline LIMIT 1 Execute alias
Result
|
|
|
Deletes the specified alias. Examples
Result
serverversion select version() |
|
where |
If the input is a parameter, this command echoes (displays) the value of the parameter. The parameter must be prefixed according to its type. See Table 3 for details. If the input is not a parameter, the command echoes the statement as is. If the input is an alias, the command displays the value of an alias command. Examples
Result
select version() |
|
none |
||
|
Displays the help information for the specified command. When used without any arguments, it lists all the commands supported by the cbq shell. Example
Result
\ECHO args ... Echo the input value. args can be a name (a prefixed-parameter), an alias (command alias) or a value (any input statement). Example : \ECHO -$r ; \ECHO \\tempalias; |
|
none |
Displays the copyright, attributions, and distribution terms. Example
|
|
|
Reads and executes the commands from a file.
Multiple commands in the input file must be separated by For example, sample.txt contains the following commands: SELECT * FROM `travel-sample`.inventory.airline LIMIT 1; \ECHO this; #This is a comment; Example
|
|
|
Redirects the output of all the commands to the specified file until the cbq shell receives the If the file doesn’t exist, it is created. If the file already exists, it is overwritten. You can append redirected output to an existing file using File Append Mode. Example
|
|
none |
Redirects the output of subsequent commands from a custom file to standard output (os.stdout). Example
|
Connecting to the Cluster or Query Node
You can connect the cbq shell to Couchbase Server either through the query service or through the cluster endpoint. There are two ways to establish a connection:
-
Using an option on startup:
-e <url to query engine or Couchbase cluster> --engine=<url to query engine or Couchbase cluster>
-
Using a shell command:
cbq> \CONNECT url;
The url
may contain up to three components: the protocol scheme, the host, and a port number.
The URL is optional and if it is not specified, the default URL http://localhost:8091
is used.
An error is thrown if the URL is invalid.
The cbq shell supports the http://, https://, couchbase:// and couchbases:// protocol schemes. The https:// and couchbases:// protocol schemes are encrypted. For more details, refer to Using an Encrypted Connection.
The host may be the IP address or hostname of any node in the cluster, as cbq will automatically discover the query nodes. The cbq shell supports both IPV4 and IPV6 addresses.
The couchbase:// and couchbases:// protocol schemes support the domain name service (DNS). When using one of these protocol schemes, the host may be a domain name which is resolved using DNS. For example, this enables you to connect to a cluster or node over the internet.
Note that you must use the encrypted couchbases:// protocol scheme to connect to a cluster or node deployed in Couchbase Capella.
You may optionally specify the port when using the http:// or https:// protocol schemes. When connecting to the query service, use the query port 8093, or 18093 for an encrypted connection. When connecting to the cluster, you don’t need to specify the port as the connection uses round robin to find a query service to connect to. If you want to specify a port, use the admin port 8091, or 18091 for an encrypted connection.
You cannot specify the port when using the couchbase:// or couchbases:// protocol schemes.
You can close the connection with an existing node or cluster without exiting the shell at any given time during the session using the \DISCONNECT;
command.
If the shell is not connected to any endpoint, an error with a message that the shell is not connected to any instance is thrown.
$ ./cbq -e http://localhost:8091 -u Administrator -p password
Connected to : http://localhost:8091/. Type Ctrl-D or \QUIT to exit.
Path to history file for the shell : ~/.cbq_history
cbq> \DISCONNECT;
Couchbase query shell not connected to any endpoint. Use \CONNECT command to connect.
cbq> \CONNECT http://127.0.0.1:8091;
Connected to : http://127.0.0.1:8091. Type Ctrl-D or \QUIT to exit.
cbq> \EXIT;
$ ./cbq -e http://127.0.0.1:8091 -u Administrator -p password
Connected to : http://127.0.0.1:8091/. Type Ctrl-D or \QUIT to exit.
Path to history file for the shell : ~/.cbq_history
cbq>
Bringing Up an Unconnected Instance
You can bring up the shell without connecting to any query service or cluster endpoint by using the -ne
or --no-engine
option.
After starting cbq without any service, you can connect to a specific endpoint using the CONNECT
command.
$ ./cbq -ne
Path to history file for the shell : ~/.cbq_history
cbq> \CONNECT http://Administrator:password@localhost;
Connected to : http://Administrator:password@localhost:8091. Type Ctrl-D or \QUIT to exit.
Exiting the cbq Shell
You can exit the cbq shell by pressing Ctrl+D or by using one of the following commands:
cbq> \EXIT;
cbq> \QUIT;
When you run the exit command, the cbq shell first saves the history, closes existing connections, saves the current session in a session file, resets all environment variables, and then closes the shell liner interface.
$ ./cbq -u Administrator -p password
Connected to : http://localhost:8091/. Type Ctrl-D or \QUIT to exit.
Path to history file for the shell : ~/.cbq_history
cbq> SELECT name FROM `travel-sample`.inventory.airline LIMIT 1;
{
"requestID": "59d1c699-11a2-47c6-b4d0-4a7de1d15a3c",
"signature": {
"name": "json"
},
"results": [
{
"name": "40-Mile Air"
}
],
"status": "success",
"metrics": {
"elapsedTime": "13.514441ms",
"executionTime": "13.355058ms",
"resultCount": 1,
"resultSize": 37,
"serviceLoad": 12
}
}
cbq> \EXIT;
$
Accessing a Secure Keyspace
If your keyspace has a password, you can pass the keyspace name and keyspace password like so:
$ ./cbq -engine="http://<keyspacename>:<keyspacepassword>@localhost:8091/"
For the 'travel-sample' keyspace, if you add a password to it of w1fg2Uhj89 (as by default it has none), the command to start cbq
would look like this:
$ ./cbq -engine="http://travel-sample:w1fg2Uhj89@localhost:8091/"
These commands execute successfully only if you have loaded sample bucket 'travel-sample' either at install or from the Settings menu in the web UI. |
If you want to access all of the keyspaces in the same cbq session, you would pass in the Administrator username and password instead of the keyspace level.
$ ./cbq -engine="http://Administrator:password@localhost:8091/"
Providing Single User Credentials
You can pass a single user name credential to the cbq shell on startup using the command line options:
-u=username --user=username
The shell then prompts you for a password.
You can also provide a single password credential using the -p
option.
You cannot use this option by itself.
It must be used with the -u
option to specify the user name that the password is associated with.
-p=password --password=password
$ ./cbq -u=Administrator
Enter Password:
Connected to : http://localhost:8091/. Type Ctrl-D or \QUIT to exit.
$ ./cbq -e http://localhost:8091 -u=Administrator -p=password
Connected to : http://localhost:8091/. Type Ctrl-D or \QUIT to exit.
cbq>
For information on passing the user name and password credentials using other mechanisms, see Passing Credentials Using the SET Shell Command and Passing Credentials Using REST API.
Providing Multiple Credentials for Authorization
The cbq shell supports self-signed certificates for encrypting communication between clusters.
Using the cbq shell, you can set the credentials for different users on startup or by using the SET shell commands to set the credentials query parameter. You can also use this to provide authentication credentials for multiple SASL buckets per session. Depending on the type of credential being set, there are multiple possible values for the credentials query parameter.
To set the credentials for different users on startup, use one of the following options:
-c=list-of-creds --credentials=list-of-creds
The list-of-creds
can take either one or multiple credentials.
The credentials consist of an identity and a password separated by a colon :
.
To specify multiple credentials, append all the user names and passwords to the same credentials array.
For example:
-c=travel-sample:pwd1,beer-sample:pwd2
For information on passing a single user name credential to the cbq shell, see Providing Single User Credentials.
Passing Credentials Using the SET Shell Command
You can provide the credential types using the SET command.
The credentials are set for the shell session and not on a per query basis. You can use the SET, PUSH, POP and UNSET commands to reset the credentials during a session. |
To pass authentication credentials per query, set the query parameter to a new value using the SET shell command before executing the query.
You can also switch between users and change credentials during a session.
To do so, set the -creds
query parameter for the session using the following command:
cbq> \SET -creds travel-sample:b1, session:s1;
Passing Credentials Using Query REST API
You can use query REST API to pass credentials from clients.
For SASL buckets, you can pass the credentials as:
[ {
"user":"travel-sample",
"pass":"password"
} ]
If you are using the Administrator credentials:
[ {
"user":"Administrator",
"pass":"password"
} ]
For multiple SASL protected buckets, you can pass an array of authentication credentials:
[ {
"user":"beer-sample",
"pass":"password1"
},
{
"user":"travel-sample",
"pass":"password2"
} ]
Displaying the Credentials
You can display the credentials for the current session using the ECHO shell command. This command displays only the user names (and not the passwords).
cbq> \ECHO -creds;
Administrator:*
You can also display a full list of variables using the SET command specified without any arguments.
cbq> \SET;
Query Parameters ::
Parameter name : timeout Value ["3ms" "4s"]
Named Parameters ::
Parameter name : r Value [9.5 9.5]
User Defined Session Parameters ::
Predefined Session Parameters ::
Parameter name : histfile Value [".cbq_history"]
Using an Encrypted Connection
You can connect to the cluster or node with an encrypted protocol scheme — that is, either https:// or couchbases://. To do this, you can provide the root CA certificate, the chain certificate, and the client key file using the --cacert, --cert, and --key options. You can use the --no-ssl-verify option to skip the verification of certificates.
When connecting to a cluster or node with an encrypted protocol scheme, the default ports are 18091 and 18093. You need not specify the port when connecting to the cluster.
You can use the encrypted couchbases:// protocol scheme with a domain name to connect to a node or cluster deployed in Couchbase Capella. For more details, refer to Connecting to the Cluster or Query Node.
Parameter Manipulation
The cbq shell categorizes parameters into the following types:
-
Named Parameters
-
REST API Parameters
-
Session or Pre-defined Parameters
-
User-defined Parameters
Parameter Configuration
When using parameters, you can set a stack of values for each parameter. You can either push a new value onto the stack using the PUSH command, or set the current value for a parameter using the SET command. The SET command always modifies the top of a variable’s stack while the PUSH command adds to the stack. When you use PUSH with no arguments, it copies the top element of every parameter’s (except the predefined parameters) stack and pushes that copy to the top of its respective stack. As a result, each stack grows by 1, but the values are preserved. You can then use the SET command to modify the top value.
To unset the values from a parameter’s stack, you can use the UNSET command to remove all the values from the stack and delete the corresponding parameter stack. However, if you want to delete a single value from the settings, use the POP command. When you use the POP command with no arguments, it pops the one value from the top of each parameter’s stack.
Setting Variable Values
Each variable has a separate stack associated with it and the prefix
name
argument helps distinguish between the stacks.
The SET command always modifies the top value of a variable. You can use the SET command to set different kinds of parameters: query parameter, predefined session variables, user-defined session variables and named parameters.
cbq> \SET <prefix><name> value;
where name
is the name of the parameter, value
is the value to be set, and prefix
is one of the following depending on the parameter type.
The cbq shell uses the prefix to differentiate between the different types of parameters.
Prefix | Parameter Type |
---|---|
- |
Query parameter |
-$ |
Named parameters |
No prefix |
Predefined (built-in) session variable |
$ |
User defined session variable |
Positional parameters are set using the -args query parameter.
|
You can use the cbq shell to set all the REST API settings by specifying the settings as query parameters prefixed by -
.
As a best practice, we recommend that you save the initial set of basic parameters and their default values using the \PUSH
command (with no arguments).
cbq> \SET -$airport "SJC";
cbq> \PUSH -args ["LAX", 6];
cbq> \SET;
Query Parameters ::
Parameter name : args Value [["LAX",6]]
Named Parameters ::
Parameter name : airport Value ["SJC"]
User Defined Session Parameters ::
Predefined Session Parameters ::
Parameter name : histfile Value [".cbq_history"]
cbq> \PUSH -$airport "SFO";
cbq> \PUSH;
cbq> \SET;
Query Parameters ::
Parameter name : args Value [["LAX",6] ["LAX",6]]
Named Parameters ::
Parameter name : airport Value ["SJC" "SFO" "SFO"]
User Defined Session Parameters ::
Predefined Session Parameters ::
Parameter name : histfile Value [".cbq_history"]
cbq> \SET -args ["SFO", 8];
cbq> \SET;
Query Parameters ::
Parameter name : args Value [["LAX",6] ["SFO",8]]
Named Parameters ::
Parameter name : airport Value ["SJC" "SFO" "SFO"]
User Defined Session Parameters ::
Predefined Session Parameters ::
Parameter name : histfile Value [".cbq_history"]
cbq> \POP;
cbq> \SET;
Query Parameters ::
Parameter name : args Value [["LAX",6]]
Named Parameters ::
Parameter name : airport Value ["SJC" "SFO"]
User Defined Session Parameters ::
Predefined Session Parameters ::
Parameter name : histfile Value [".cbq_history"]
cbq> \POP -$airport;
cbq> \SET;
Query Parameters ::
Parameter name : args Value [["LAX",6]]
Named Parameters ::
Parameter name : airport Value ["SJC"]
User Defined Session Parameters ::
Predefined Session Parameters ::
Parameter name : histfile Value [".cbq_history"]
cbq> \UNSET -$airport;
cbq> \SET;
Query Parameters ::
Parameter name : args Value [["LAX",6]]
Named Parameters ::
User Defined Session Parameters ::
Predefined Session Parameters ::
Parameter name : histfile Value [".cbq_history"]
To display all the parameters defined in a session, use the SET command with no arguments.
cbq> \SET;
Query Parameters ::
Parameter name : timeout Value ["100m"]
Named Parameters ::
Parameter name : r Value [9.5]
User Defined Session Parameters ::
Predefined Session Parameters ::
Parameter name : histfile Value [".cbq_history"]
The following table lists the available predefined session variables.
Variable Name | Possible Values | Description |
---|---|---|
HISTFILE |
Valid file name |
Specifies the file name to store the command history. By default the file is saved in the user’s home directory. Default: .cbq_history |
Handling Named Parameters
Use the \SET command to define named parameters.
For each named parameter, prefix the variable name with -$
.
The following example creates named parameters r
and date
with values 9.5 and "1-1-2016" respectively.
cbq> \SET -$r 9.5;
cbq> \SET -$date "1-1-2016";
Handling Positional Parameters
Use the SET shell command with the -args
query parameter to define positional parameters:
cbq> \SET -args value;
The value
contains the different values that correspond to positions within the query.
For example,
cbq> \SET -args [ 9.5, "1-1-2016"];
Resetting Variable Values
You can reset the value of a variable by either popping it or deleting it altogether. To pop the top of a parameter’s stack use:
cbq> \POP <prefix><name>;
To pop the top of every parameter’s stack once, use the POP command without any arguments:
cbq> \POP;
To pop all the values of a parameter’s stack and then delete the parameter, use:
cbq> \UNSET <prefix><name>;
Using ECHO to Display Values of Parameters and More
The ECHO command displays the current values of the parameters set for a session. You can use it to display any input string or command aliases that have been created using the ALIAS shell command. To display parameters, you must include their prefixes. If not, the shell considers the parameters as generic statements and displays the parameter as is.
cbq> \ECHO input ... ;
where input
can be a parameter with prefix (<prefix><parameter-name>
), an alias (\\command-alias
), a SQL++ statement, or a string.
cbq> \ECHO hello;
hello
cbq> \ECHO \\travel-alias1;
SELECT * FROM `travel-sample`.inventory.airline LIMIT 1;
cbq> \ECHO -$r;
9.5
Command Alias
Using the ALIAS shell command, you can define and store aliases for commands. This is useful when you have lengthy queries that need to be executed often. Run the following command to define an alias:
cbq> \ALIAS command-alias command;
cbq> \ALIAS travel-alias1 SELECT * FROM `travel-sample`.inventory.airline LIMIT 1;
To run the command alias, use \\command-alias
.
cbq> \\travel-alias1;
{
"requestID": "b25c84d6-7b7b-440a-a286-5027e6ecbbb5",
"signature": {
"*": "*"
},
"results": [
{
"airline": {
"callsign": "MILE-AIR",
"country": "United States",
"iata": "Q5",
"icao": "MLA",
"id": 10,
"name": "40-Mile Air",
"type": "airline"
}
}
],
"status": "success",
...
}
To list all the existing aliases, use:
cbq> \ALIAS;
cbq> \ALIAS;
serverversion select version()
travel-alias1 SELECT * FROM `travel-sample`.inventory.airline LIMIT 1;
You can delete a defined alias using the \UNLIAS command.
cbq> \UNALIAS alias-name ... ;
cbq> \UNALIAS serverversion travel-alias1;
/* Check existing aliases */
cbq> \ALIAS;
ERROR 141 : Alias does not exist :
This command can take multiple arguments and deletes the defined alias for every input name.
Executing Prepared Statements
You can use the shell command to execute prepared statements. As a pre-requisite, you must first prepare a statement using the SQL++ PREPARE statement. To execute prepared statements, follow these steps:
-
Set the named and positional parameters that are present in the prepared statement.
-
Prepare using the SQL++ PREPARE statement. This can be either prepared statement or a named prepared statement. If you do not specify a name for the prepared statement (
PREPARE query;
), a unique name is assigned. You can use this auto-assigned name when executing the prepared statement. If you specify a name (PREPAREname
FROMquery
;), you can use this name to run the prepared statement. -
Execute the prepared statement using the shell command:
EXECUTE name-of-prepared-stmt;
Canceling a Query
You can cancel a running query by using the Ctrl+C keys.
Connection Timeout Parameter
You can use the timeout parameter to limit the running time of a query. This parameter specifies the time to wait before returning an error when executing a query.
--t=value --timeout=value
Timeout can be specified in the following units: ns
for nanoseconds, μs
for microseconds, ms
for milliseconds, s
for seconds, m
for minutes, and h
for hours.
Examples of valid values include "0.5s", "10ms", or "1m".
You can also the SET shell command to set this parameter. An error is thrown if the timeout is invalid.
$ ./cbq --timeout="2s"
$ ./cbq -q
cbq> \SET -TIMEOUT 1ms;
File Based Operations
Using the file based commands and options, the cbq shell can execute SQL++ and shell commands contained in files. There are two ways to accomplish this:
-
Using an option on startup:
-f=input-file --file=input-file
The cbq shell executes the commands present in the input file, prints them to stdout (or to a file if using redirects), and exits.
-
Using a shell command:
cbq> \SOURCE input-file;
Runs the commands present in the input file and prints the result to stdout.
Consider the input file, sample.txt, containing the following commands:
CREATE PRIMARY INDEX ON `travel-sample`.inventory.airline USING GSI; SELECT * from `travel-sample`.inventory.airline LIMIT 2; SELECT callsign from `travel-sample`.inventory.airline LIMIT 3; \HELP;
To execute the commands contained in sample.txt using the -f option, run $./cbq -f=sample.txt
Connected to : http://localhost:8091/. Type Ctrl-D or \QUIT to exit.
Path to history file for the shell : ~/.cbq_history
CREATE PRIMARY INDEX ON `travel-sample`.inventory.airline USING GSI;
{ ...
"results": [ ],
...
}
SELECT * from `travel-sample`.inventory.airline LIMIT 2;
{ ...
"results": [ ],
...
}
SELECT callsign from `travel-sample`.inventory.airline LIMIT 3;
{ ...
"results": [ ],
...
}
\HELP;
Help information for all shell commands.
...
$
To execute the commands contained in sample.txt using the shell command, run cbq> \SOURCE sample.txt;
CREATE PRIMARY INDEX ON `travel-sample`.inventory.airline USING GSI;
{ ...
"results": [ ],
...
}
SELECT * from `travel-sample`.inventory.airline LIMIT 2;
{ ...
"results": [ ],
...
}
SELECT callsign from `travel-sample`.inventory.airline LIMIT 3;
{ ...
"results": [ ],
...
}
\HELP;
Help information for all shell commands.
...
cbq>
Redirecting Results to a File
You can redirect all the output for a session or part of a session to a specified file by using the following option:
-o filename --output=filename
To redirect a specific set of commands during a session, you must specify the commands between \REDIRECT
and \REDIRECT OFF
as shown:
cbq> \REDIRECT filename;
command-1; command-2;, ..., command-n;
cbq> \REDIRECT OFF;
All the commands specified after \REDIRECT
and before \REDIRECT OFF
are saved into the specified output file.
If the file doesn’t exist, it is created. If the file already exists, it is overwritten. You can append redirected output to an existing file using File Append Mode.
cbq> \REDIRECT temp_output.txt;
cbq> CREATE PRIMARY INDEX ON `travel-sample`.inventory.airline USING GSI;
cbq> SELECT * FROM `travel-sample`.inventory.airline LIMIT 1;
cbq> \HELP;
cbq> \REDIRECT OFF;
You can specify multiple \REDIRECT
commands.
When you do so, the output file changes to the specified files and switches back to stdout
only when you specify \REDIRECT OFF
.
File Append Mode
You can use file append mode to specify that cbq should append redirected output to the end of an existing file, rather than overwriting the existing file.
To use file append mode, include a plus sign +
at the start of the output path or filename.
cbq> \REDIRECT +temp_output.txt;
cbq> SELECT * FROM `travel-sample`.inventory.airline LIMIT 1;
cbq> \REDIRECT OFF;
Every time you start appending to the output file, a timestamp is added to the end of the output file, followed by any redirected commands and results.
-- <2021-07-30T14:48:43.661+01:00> : opened in append mode SELECT * FROM `travel-sample`.inventory.airline LIMIT 1 ...
Note that file append mode is only available with the \REDIRECT
command within a shell session.
It is not available for the -o
or --output
command line option.
When you use the -o
or --output
command line option, the specified output file is always overwritten.
Server and Shell Information
The cbq shell provides commands that convey information about the shell or cluster endpoints.
Version
You can find the version of the client (shell) by using either the command line option to display the current version of the shell and exit, or as a shell command to print the version of the shell during the shell session.
$ ./cbq -v
SHELL VERSION : 2.0
Use {sqlpp} queries select version(); or select min_version(); to display server version.
$ ./cbq --version
SHELL VERSION : 2.0
Use {sqlpp} queries select version(); or select min_version(); to display server version.
cbq> \VERSION;
SHELL VERSION : 2.0
To display the version of the query service, use the SQL++ commands SELECT version();
and SELECT min_version();
.
Copyright
You can view the copyright, attributions, and distribution terms of the command line query tool using the \COPYRIGHT;
command.
cbq> \COPYRIGHT;
Copyright (c) 2016 Couchbase, Inc. Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License. You may obtain a copy of the
License at http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the
License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
either express or implied. See the License for the specific language governing permissions
and limitations under the License.
cbq>
Shortcut Keys for cbq Shell
The following table lists the shortcut keys used by the cbq
shell.
Keystroke | Action |
---|---|
Ctrl+A, Home |
Move cursor to beginning of line |
Ctrl+E, End |
Move cursor to end of line |
Ctrl+B, Left |
Move cursor one character left |
Ctrl+F, Right |
Move cursor one character right |
Ctrl+Left |
Move cursor to previous word |
Ctrl+Right |
Move cursor to next word |
Ctrl+D, Del |
(if line is not empty) Delete character under cursor |
Ctrl+D |
(if line is empty) End of File - usually quits application |
Ctrl+C |
Reset input (create new empty prompt) |
Ctrl+L |
Clear screen (line is unmodified) |
Ctrl+T |
Transpose previous character with current character |
Ctrl+H, BackSpace |
Delete character before cursor |
Ctrl+W |
Delete word leading up to cursor |
Ctrl+K |
Delete from cursor to end of line |
Ctrl+U |
Delete from start of line to cursor |
Ctrl+P, Up |
Previous match from history |
Ctrl+N, Down |
Next match from history |
Ctrl+R |
Reverse Search history (Ctrl+S forward, Ctrl+G cancel) |
Ctrl+Y |
Paste from Yank buffer (Alt+Y to paste next yank instead) |
Tab |
Next completion |
Shift+Tab |
(after Tab) Previous completion |
Source: https://github.com/peterh/liner