TRUNCATE命令用于截断表。 如果您截断表,表的所有行将永久删除。
语法:
TRUNCATE <tablename>
示例:
我们有一个名为“student”的表具有以下数据(创建表并插入数据):
cqlsh:zaixian_ks> CREATE TABLE student(
             ...    student_id int PRIMARY KEY,
             ...    student_name text,
             ...    student_fees varint
             ...  );
cqlsh:zaixian_ks>
cqlsh:zaixian_ks> INSERT INTO student (student_id, student_fees, student_name)
             ... VALUES(1,5000, 'Maxsu');
cqlsh:zaixian_ks> INSERT INTO student (student_id, student_fees, student_name)
             ... VALUES(2,3000, 'Minsu');
cqlsh:zaixian_ks> INSERT INTO student (student_id, student_fees, student_name)
             ... VALUES(3, 2000, 'Modlee');
cqlsh:zaixian_ks>
cqlsh:zaixian_ks> select * from student;
 student_id | student_fees | student_name
------------+--------------+--------------
          1 |         5000 |        Maxsu
          2 |         3000 |        Minsu
          3 |         2000 |       Modlee
(3 rows)
cqlsh:zaixian_ks>
现在,我们使用TRUNCATE命令:
TRUNCATE student;
现在表已经被截断了,您可以使用SELECT命令验证它。
SELECT * FROM student;
如下图所示 -

您可以看到表student现在被截断。
						上一篇:
								Cassandra删除表
												下一篇:
								Cassandra创建索引
												
						
						
					
					
					