---
layout: global
title: ALTER TABLE
displayTitle: ALTER TABLE
license: |
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---
### Description
`ALTER TABLE` statement changes the schema or properties of a table.
### RENAME
`ALTER TABLE RENAME` statement changes the table name of an existing table in the database.
#### Syntax
{% highlight sql %}
ALTER TABLE table_identifier RENAME TO table_identifier
ALTER TABLE table_identifier partition_spec RENAME TO partition_spec
{% endhighlight %}
#### Parameters
table_identifier
-
Specifies a table name, which may be optionally qualified with a database name.
Syntax:
[ database_name. ] table_name
partition_spec
-
Partition to be renamed.
Syntax:
PARTITION ( partition_col_name = partition_col_val [ , ... ] )
### ADD COLUMNS
`ALTER TABLE ADD COLUMNS` statement adds mentioned columns to an existing table.
#### Syntax
{% highlight sql %}
ALTER TABLE table_identifier ADD COLUMNS ( col_spec [ , col_spec ... ] )
{% endhighlight %}
#### Parameters
table_identifier
-
Specifies a table name, which may be optionally qualified with a database name.
Syntax:
[ database_name. ] table_name
COLUMNS ( col_spec )
- Specifies the columns to be added to be renamed.
### SET AND UNSET
#### SET TABLE PROPERTIES
`ALTER TABLE SET` command is used for setting the table properties. If a particular property was already set,
this overrides the old value with the new one.
`ALTER TABLE UNSET` is used to drop the table property.
##### Syntax
{% highlight sql %}
--Set Table Properties
ALTER TABLE table_identifier SET TBLPROPERTIES ( key1 = val1, key2 = val2, ... )
--Unset Table Properties
ALTER TABLE table_identifier UNSET TBLPROPERTIES [ IF EXISTS ] ( key1, key2, ... )
{% endhighlight %}
#### SET SERDE
`ALTER TABLE SET` command is used for setting the SERDE or SERDE properties in Hive tables. If a particular property was already set,
this overrides the old value with the new one.
##### Syntax
{% highlight sql %}
--Set SERDE Properties
ALTER TABLE table_identifier [ partition_spec ]
SET SERDEPROPERTIES ( key1 = val1, key2 = val2, ... )
ALTER TABLE table_identifier [ partition_spec ] SET SERDE serde_class_name
[ WITH SERDEPROPERTIES ( key1 = val1, key2 = val2, ... ) ]
{% endhighlight %}
#### SET LOCATION And SET FILE FORMAT
`ALTER TABLE SET` command can also be used for changing the file location and file format for
existing tables.
##### Syntax
{% highlight sql %}
--Changing File Format
ALTER TABLE table_identifier [ partition_spec ] SET FILEFORMAT file_format
--Changing File Location
ALTER TABLE table_identifier [ partition_spec ] SET LOCATION 'new_location'
{% endhighlight %}
#### Parameters
table_identifier
-
Specifies a table name, which may be optionally qualified with a database name.
Syntax:
[ database_name. ] table_name
partition_spec
-
Specifies the partition on which the property has to be set.
Syntax:
PARTITION ( partition_col_name = partition_col_val [ , ... ] )
SERDEPROPERTIES ( key1 = val1, key2 = val2, ... )
- Specifies the SERDE properties to be set.
### Examples
{% highlight sql %}
--RENAME table
DESC student;
+--------------------------+------------+----------+--+
| col_name | data_type | comment |
+--------------------------+------------+----------+--+
| name | string | NULL |
| rollno | int | NULL |
| age | int | NULL |
| # Partition Information | | |
| # col_name | data_type | comment |
| age | int | NULL |
+--------------------------+------------+----------+--+
ALTER TABLE Student RENAME TO StudentInfo;
--After Renaming the table
DESC StudentInfo;
+--------------------------+------------+----------+--+
| col_name | data_type | comment |
+--------------------------+------------+----------+--+
| name | string | NULL |
| rollno | int | NULL |
| age | int | NULL |
| # Partition Information | | |
| # col_name | data_type | comment |
| age | int | NULL |
+--------------------------+------------+----------+--+
--RENAME partition
SHOW PARTITIONS StudentInfo;
+------------+--+
| partition |
+------------+--+
| age=10 |
| age=11 |
| age=12 |
+------------+--+
ALTER TABLE default.StudentInfo PARTITION (age='10') RENAME TO PARTITION (age='15');
--After renaming Partition
SHOW PARTITIONS StudentInfo;
+------------+--+
| partition |
+------------+--+
| age=11 |
| age=12 |
| age=15 |
+------------+--+
-- Add new column to a table
DESC StudentInfo;
+--------------------------+------------+----------+--+
| col_name | data_type | comment |
+--------------------------+------------+----------+--+
| name | string | NULL |
| rollno | int | NULL |
| age | int | NULL |
| # Partition Information | | |
| # col_name | data_type | comment |
| age | int | NULL |
+--------------------------+------------+----------+
ALTER TABLE StudentInfo ADD columns (LastName string, DOB timestamp);
--After Adding New columns to the table
DESC StudentInfo;
+--------------------------+------------+----------+--+
| col_name | data_type | comment |
+--------------------------+------------+----------+--+
| name | string | NULL |
| rollno | int | NULL |
| LastName | string | NULL |
| DOB | timestamp | NULL |
| age | int | NULL |
| # Partition Information | | |
| # col_name | data_type | comment |
| age | int | NULL |
+--------------------------+------------+----------+--+
--Change the fileformat
ALTER TABLE loc_orc SET fileformat orc;
ALTER TABLE p1 partition (month=2, day=2) SET fileformat parquet;
--Change the file Location
ALTER TABLE dbx.tab1 PARTITION (a='1', b='2') SET LOCATION '/path/to/part/ways'
-- SET SERDE/ SERDE Properties
ALTER TABLE test_tab SET SERDE 'org.apache.hadoop.hive.serde2.columnar.LazyBinaryColumnarSerDe';
ALTER TABLE dbx.tab1 SET SERDE 'org.apache.madoop' WITH SERDEPROPERTIES ('k' = 'v', 'kay' = 'vee')
--SET TABLE PROPERTIES
ALTER TABLE dbx.tab1 SET TBLPROPERTIES ('winner' = 'loser')
--DROP TABLE PROPERTIES
ALTER TABLE dbx.tab1 UNSET TBLPROPERTIES ('winner')
{% endhighlight %}
### Related Statements
- [CREATE TABLE](sql-ref-syntax-ddl-create-table.html)
- [DROP TABLE](sql-ref-syntax-ddl-drop-table.html)