DROP

This section describes the basic syntax and usage of the SQL statement for deleting a ClickHouse table.

DROP [TEMPORARY] TABLE [IF EXISTS] [database_name.]name [ON CLUSTER cluster] [SYNC]

Examples:

Delete the t1 table.

drop table t1 SYNC;

When you delete a replication table, create a path on ZooKeeper to store related data. The default library engine of ClickHouse is the atomic database engine. After a table in the atomic database is deleted, it is not deleted immediately but deleted 24 hours later. To resolve this issue, when deleting a table, add the SYNC field to the deletion command, for example, drop table t1 SYNC;
This issue does not occur when a local or distributed table is deleted. The SYNC field is not required in your deletion command, for example, drop table t1;
If the table creation statement contains ON CLUSTER ClickHouse cluster name, run the following command to delete the table:
```
drop table Table name ON CLUSTER default_cluster;
```
If the table creation statement does not contain ON CLUSTER ClickHouse cluster name, run the following command to delete the table:
```
drop table Table name;
```
Before deleting a data table, check whether the data table is in use to avoid unnecessary troubles. After a data table is deleted, it can be restored within 24 hours. The restoration command is as follows:
```
set allow_experimental_undrop_table_query = 1;
```
```
UNDROP TABLE Data table name;
```