truncate command deletes all records from specified table or all values from specified column.
truncate コマンドの引数は1つだけです:
The required parameter is only target_name:
truncate target_name
バージョン 4.0.9 で追加: 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.
Here is a simple example of truncate command against a table.
実行例:
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.
実行例:
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
# ]
# ]
# ]
# ]
このセクションでは truncate の引数について説明します。