alter

alter table tableObj add columnName columnType;
alter table tableObj drop [column] columnName;
alter table tableObj rename [column] columnName to newColumnName;

tableObj can be an in-memory table, a stream table, a DFS table, or a dimension table.

colNames is a string scalar indicating the name of the column to be added.

newColNames is a string scalar indicating the name of the column to be modified.

colTypes is a scalar indicating the data type of the column.

The alter statement is used to add, delete or rename columns to an existing table. Note that the TSDB engine only supports the add operation.

if(existsDatabase("dfs://test")) dropDatabase("dfs://test")
create database "dfs://test" partitioned by VALUE(1..10), HASH([SYMBOL, 40]), engine='OLAP', atomic='TRANS', chunkGranularity='TABLE'

create table "dfs://test"."pt"(
    id INT,
    deviceId SYMBOL,
    date DATE[comment="time_col", compress="delta"],
    value DOUBLE,
     isFin BOOL
)
partitioned by ID, deviceID

pt = loadTable("dfs://test", `pt)
alter table pt add location SYMBOL;
pt = loadTable("dfs://test", `pt)
pt.schema().colDefs

alter table pt rename location to loc
pt = loadTable("dfs://test", `pt)
pt.schema().colDefs

alter table pt drop value
pt = loadTable("dfs://test", `pt)
pt.schema().colDefs

Related functions: addColumn, dropColumns!, rename!.