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Cassandra – Create Table ”; Previous Next Creating a Table You can create a table using the command CREATE TABLE. Given below is the syntax for creating a table. Syntax CREATE (TABLE | COLUMNFAMILY) <tablename> (”<column-definition>” , ”<column-definition>”) (WITH <option> AND <option>) Defining a Column You can define a column as shown below. column name1 data type, column name2 data type, example: age int, name text Primary Key The primary key is a column that is used to uniquely identify a row. Therefore,defining a primary key is mandatory while creating a table. A primary key is made of one or more columns of a table. You can define a primary key of a table as shown below. CREATE TABLE tablename( column1 name datatype PRIMARYKEY, column2 name data type, column3 name data type. ) or CREATE TABLE tablename( column1 name datatype PRIMARYKEY, column2 name data type, column3 name data type, PRIMARY KEY (column1) ) Example Given below is an example to create a table in Cassandra using cqlsh. Here we are − Using the keyspace tutorialspoint Creating a table named emp It will have details such as employee name, id, city, salary, and phone number. Employee id is the primary key. cqlsh> USE tutorialspoint; cqlsh:tutorialspoint>; CREATE TABLE emp( emp_id int PRIMARY KEY, emp_name text, emp_city text, emp_sal varint, emp_phone varint ); Verification The select statement will give you the schema. Verify the table using the select statement as shown below. cqlsh:tutorialspoint> select * from emp; emp_id | emp_city | emp_name | emp_phone | emp_sal ——–+———-+———-+———–+——— (0 rows) Here you can observe the table created with the given columns. Since we have deleted the keyspace tutorialspoint, you will not find it in the keyspaces list. Creating a Table using Java API You can create a table using the execute() method of Session class. Follow the steps given below to create a table using Java API. Step1: Create a Cluster Object First of all, create an instance of the Cluster.builder class of com.datastax.driver.core package as shown below. //Creating Cluster.Builder object Cluster.Builder builder1 = Cluster.builder(); Add a contact point (IP address of the node) using the addContactPoint() method of Cluster.Builder object. This method returns Cluster.Builder. //Adding contact point to the Cluster.Builder object Cluster.Builder builder2 = build.addContactPoint( “127.0.0.1” ); Using the new builder object, create a cluster object. To do so, you have a method called build() in the Cluster.Builder class. The following code shows how to create a cluster object. //Building a cluster Cluster cluster = builder.build(); You can build a cluster object using a single line of code as shown below. Cluster cluster = Cluster.builder().addContactPoint(“127.0.0.1”).build(); Step 2: Create a Session Object Create an instance of Session object using the connect() method of Cluster class as shown below. Session session = cluster.connect( ); This method creates a new session and initializes it. If you already have a keyspace, you can set it to the existing one by passing the keyspace name in string format to this method as shown below. Session session = cluster.connect(“ Your keyspace name ” ); Here we are using the keyspace named tp. Therefore, create the session object as shown below. Session session = cluster.connect(“ tp” ); Step 3: Execute Query You can execute CQL queries using the execute() method of Session class. Pass the query either in string format or as a Statement class object to the execute() method. Whatever you pass to this method in string format will be executed on the cqlsh. In the following example, we are creating a table named emp. You have to store the query in a string variable and pass it to the execute() method as shown below. //Query String query = “CREATE TABLE emp(emp_id int PRIMARY KEY, ” + “emp_name text, ” + “emp_city text, ” + “emp_sal varint, ” + “emp_phone varint );”; session.execute(query); Given below is the complete program to create and use a keyspace in Cassandra using Java API. import com.datastax.driver.core.Cluster; import com.datastax.driver.core.Session; public class Create_Table { public static void main(String args[]){ //Query String query = “CREATE TABLE emp(emp_id int PRIMARY KEY, ” + “emp_name text, ” + “emp_city text, ” + “emp_sal varint, ” + “emp_phone varint );”; //Creating Cluster object Cluster cluster = Cluster.builder().addContactPoint(“127.0.0.1”).build(); //Creating Session object Session session = cluster.connect(“tp”); //Executing the query session.execute(query); System.out.println(“Table created”); } } Save the above program with the class name followed by .java, browse to the location where it is saved. Compile and execute the program as shown below. $javac Create_Table.java $java Create_Table Under normal conditions, it should produce the following output − Table created Print Page Previous Next Advertisements ”;