TRUNCATE TABLE
删除表中的所有数据,同时保留表的 schema。它会删除表中的所有行,使其成为一个具有相同列和约束的空表。请注意,它不会释放分配给该表的磁盘空间。
另请参阅:DROP TABLE
语法
TRUNCATE TABLE [ <database_name>. ]table_name
示例
root@localhost> CREATE TABLE test_truncate(a BIGINT UNSIGNED, b VARCHAR);
Processed in (0.027 sec)
root@localhost> INSERT INTO test_truncate(a,b) VALUES(1234, 'databend');
1 rows affected in (0.060 sec)
root@localhost> SELECT * FROM test_truncate;
SELECT
*
FROM
test_truncate
┌───────────────────┐
│ a │ b │
│ UInt64 │ String │
├────────┼──────────┤
│ 1234 │ databend │
└───────────────────┘
1 row in 0.019 sec. Processed 1 rows, 1B (53.26 rows/s, 17.06 KiB/s)
root@localhost> TRUNCATE TABLE test_truncate;
TRUNCATE TABLE test_truncate
0 row in 0.047 sec. Processed 0 rows, 0B (0 rows/s, 0B/s)
root@localhost> SELECT * FROM test_truncate;
SELECT
*
FROM
test_truncate
0 row in 0.017 sec. Processed 0 rows, 0B (0 rows/s, 0B/s)