7.3.43. truncate

7.3.43.1. Summary

truncate command deletes all records from specified table or all values from specified column.

7.3.43.2. Syntax

truncate command takes only one parameter.

The required parameter is only target_name:

truncate target_name

New in version 4.0.9: target_name parameter can be used since 4.0.9. You need to use table parameter for 4.0.8 or earlier.

For backward compatibility, truncate command accepts table parameter. But it should not be used for newly written code.

7.3.43.3. Usage

Here is a simple example of truncate command against a table.

Execution example:

table_create Users TABLE_PAT_KEY ShortText
# [[0, 1337566253.89858, 0.000355720520019531], true]
column_create Users score COLUMN_SCALAR Int32
# [[0, 1337566253.89858, 0.000355720520019531], true]
load --table Users
[
{"_key": "Alice",  "score": 2},
{"_key": "Bob",    "score": 0},
{"_key": "Carlos", "score": -1}
]
# [[0, 1337566253.89858, 0.000355720520019531], 3]
select Users
# [
#   [
#     0,
#     1337566253.89858,
#     0.000355720520019531
#   ],
#   [
#     [
#       [
#         3
#       ],
#       [
#         [
#           "_id",
#           "UInt32"
#         ],
#         [
#           "_key",
#           "ShortText"
#         ],
#         [
#           "score",
#           "Int32"
#         ]
#       ],
#       [
#         1,
#         "Alice",
#         2
#       ],
#       [
#         2,
#         "Bob",
#         0
#       ],
#       [
#         3,
#         "Carlos",
#         -1
#       ]
#     ]
#   ]
# ]
truncate Users
# [[0, 1337566253.89858, 0.000355720520019531], true]
select Users
# [
#   [
#     0,
#     1337566253.89858,
#     0.000355720520019531
#   ],
#   [
#     [
#       [
#         0
#       ],
#       [
#         [
#           "_id",
#           "UInt32"
#         ],
#         [
#           "_key",
#           "ShortText"
#         ],
#         [
#           "score",
#           "Int32"
#         ]
#       ]
#     ]
#   ]
# ]

Here is a simple example of truncate command against a column.

Execution example:

table_create Users TABLE_PAT_KEY ShortText
# [[0, 1337566253.89858, 0.000355720520019531], true]
column_create Users score COLUMN_SCALAR Int32
# [[0, 1337566253.89858, 0.000355720520019531], true]
load --table Users
[
{"_key": "Alice",  "score": 2},
{"_key": "Bob",    "score": 0},
{"_key": "Carlos", "score": -1}
]
# [[0, 1337566253.89858, 0.000355720520019531], 3]
select Users
# [
#   [
#     0,
#     1337566253.89858,
#     0.000355720520019531
#   ],
#   [
#     [
#       [
#         3
#       ],
#       [
#         [
#           "_id",
#           "UInt32"
#         ],
#         [
#           "_key",
#           "ShortText"
#         ],
#         [
#           "score",
#           "Int32"
#         ]
#       ],
#       [
#         1,
#         "Alice",
#         2
#       ],
#       [
#         2,
#         "Bob",
#         0
#       ],
#       [
#         3,
#         "Carlos",
#         -1
#       ]
#     ]
#   ]
# ]
truncate Users.score
# [[0, 1337566253.89858, 0.000355720520019531], true]
select Users
# [
#   [
#     0,
#     1337566253.89858,
#     0.000355720520019531
#   ],
#   [
#     [
#       [
#         3
#       ],
#       [
#         [
#           "_id",
#           "UInt32"
#         ],
#         [
#           "_key",
#           "ShortText"
#         ],
#         [
#           "score",
#           "Int32"
#         ]
#       ],
#       [
#         1,
#         "Alice",
#         0
#       ],
#       [
#         2,
#         "Bob",
#         0
#       ],
#       [
#         3,
#         "Carlos",
#         0
#       ]
#     ]
#   ]
# ]

7.3.43.4. Parameters

This section describes parameters of truncate.

7.3.43.4.1. Required parameter

There is required parameter, target_name.

7.3.43.4.1.1. target_name

Specifies the name of table or column.

7.3.43.5. Return value

truncate command returns whether truncation is succeeded or not:

[HEADER, SUCCEEDED_OR_NOT]

HEADER

See Output format about HEADER.

SUCCEEDED_OR_NOT

If command succeeded, it returns true, otherwise it returns false on error.