# 4. Alter table¶

## 4.1. Synopsis¶

 ALTER TABLE { <entries> | <find_expression> } [, ... ] ADD
{ <column_name> <data_type> }
[, ... ]

find_expression ::=
FIND ( { <tag_expression> | NOT <tag_expression> } [ AND ... ] )

tag_expression ::=
TAG = 'tag_name'


## 4.2. Description¶

ALTER TABLE will modify one or more tables in a QuasarDB cluster by adding columns with the specified schema. The statement is transactional.

## 4.3. Parameters¶

table_name

The name of the table to be modified. Can be alphanumeric, but is not allowed to start with a number.

find_expression

When your tables are tagged, you can use inline key/value lookups to perform your query over multiple tables. To match all tables that have the tag “stocks”, you can use FIND(tag='stocks' AND type=ts).

column_name

The name of a column to be added to the table. Can be alphanumeric, but is not allowed to start with a number.

data_type

The data type to be associated with the column. Can be any of INT64, DOUBLE, BLOB or TIMESTAMP.

## 4.4. Examples¶

Add a single column to an existing table:

ALTER TABLE example ADD my_int INT64


Add multiple columns to an existing table:

ALTER TABLE example ADD my_int INT64, my_double DOUBLE, my_blob BLOB, my_ts TIMESTAMP