SQL-like query language for csv

Alter Table Query

Alter Table query is used to modify data structure.

Add Columns

ALTER TABLE table_name
  ADD column_name [DEFAULT value]
  [FIRST|LAST|AFTER column|BEFORE column]

ALTER TABLE table_name
  ADD (column_name [DEFAULT value] [, column_name [DEFAULT value] ...])
  [FIRST|LAST|AFTER column|BEFORE column]
table_name
identifier or Table Object
column_name
identifier
value
value

If default value is not specified, new fields are set null.

column
field reference

LAST is the default position.

Drop Columns

ALTER TABLE table_name DROP column
ALTER TABLE table_name DROP (column [, column ...])
table_name
identifier or Table Object
column
field reference

Rename Column

ALTER TABLE table_name RENAME old_column_name TO new_column_name
table_name
identifier or Table Object
old_column_name
field reference
new_column_name
identifier

Set Attribute

Set file attributes. File attributes is used to create or update files by the results of queries.

Changes to the file attributes are retained until the end of the transaction.

ALTER TABLE table_name SET attribute TO value
table_name
identifier or Table Object
attribute
identifier
name type description
FORMAT string Format
DELIMITER string Field delimiter for CSV
DELIMITER_POSITIONS string Delimiter positions for Fixed-Length Format
JSON_ESCAPE string JSON escape type
ENCODING string File Encoding
LINE_BREAK string Line Break
HEADER boolean Write header line in the file
ENCLOSE_ALL boolean Enclose all string values in CSV
PRETTY_PRINT boolean Make JSON output easier to read
value
value or identifier