Cassandra Cqlsh#
Cassandra Query Language (CQL)
Options | Usage |
---|---|
cqlsh --help | Shows help topics about the options of cqlsh commands. |
cqlsh --version | Provides the version of the cqlsh you are using. |
cqlsh --color | Directs the shell to use colored output. |
cqlsh --debug | Shows additional debugging information. |
cqlsh --execute cql_statement | Directs the shell to accept and execute a CQL command. |
cqlsh --file= “file name” | If you use this option, Cassandra executes the command in the given file and exits. |
cqlsh --no-color | Directs Cassandra not to use colored output. |
cqlsh -u “user name” | Using this option, you can authenticate a user. The default user name is: cassandra. |
cqlsh -p “pass word” | Using this option, you can authenticate a user with a password. The default password is: cassandra. |
Documented Shell Commands#
Given below are the Cqlsh documented shell commands. These are the commands used to perform tasks such as displaying help topics, exit from cqlsh, describe,etc.
HELP
− Displays help topics for all cqlsh commands.CAPTURE
− Captures the output of a command and adds it to a file.CONSISTENCY
− Shows the current consistency level, or sets a new consistency level.COPY
− Copies data to and from Cassandra.DESCRIBE
− Describes the current cluster of Cassandra and its objects.EXPAND
− Expands the output of a query vertically.EXIT
− Using this command, you can terminate cqlsh.PAGING
− Enables or disables query paging.SHOW
− Displays the details of current cqlsh session such as Cassandra version, host, or data type assumptions.SOURCE
− Executes a file that contains CQL statements.TRACING
− Enables or disables request tracing.
CQL Data Definition Commands#
CREATE KEYSPACE
− Creates a KeySpace in Cassandra.USE
− Connects to a created KeySpace.ALTER KEYSPACE
− Changes the properties of a KeySpace.DROP KEYSPACE
− Removes a KeySpaceCREATE TABLE
− Creates a table in a KeySpace.ALTER TABLE
− Modifies the column properties of a table.DROP TABLE
− Removes a table.TRUNCATE
− Removes all the data from a table.CREATE INDEX
− Defines a new index on a single column of a table.DROP INDEX
− Deletes a named index.
CQL Data Manipulation Commands#
INSERT
− Adds columns for a row in a table.UPDATE
− Updates a column of a row.DELETE
− Deletes data from a table.BATCH
− Executes multiple DML statements at once.
CQL Clauses#
SELECT
− This clause reads data from a tableWHERE
− The where clause is used along with select to read a specific data.ORDERBY
− The orderby clause is used along with select to read a specific data in a specific order.