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.