7.3.40. object_exist#

7.3.40.1. Summary#

New in version 5.0.6.

object_exist returns whether object with the specified name exists or not in database.

It’s a light operation. It just checks existence of the name in the database. It doesn’t load the specified object from disk.

object_exist doesn’t check object type. The existing object may be table, column, function and so on.

7.3.40.2. Syntax#

This command takes only one required parameter:

object_exist name

7.3.40.3. Usage#

You can check whether the name is already used in database:

Execution example:

object_exist Users
# [[0, 1337566253.89858, 0.000355720520019531], false]
table_create Users TABLE_HASH_KEY ShortText
# [[0, 1337566253.89858, 0.000355720520019531], true]
object_exist Users
# [[0, 1337566253.89858, 0.000355720520019531], true]

The object_exist Users returns false before you create Users table.

The object_exist Users returns true after you create Users table.

7.3.40.4. Parameters#

This section describes all parameters.

7.3.40.4.1. Required parameters#

There is only one required parameter.

7.3.40.4.1.1. name#

Specifies the object name to be checked.

If you want to check existence of a column, use TABLE_NAME.COLUMN_NAME format like the following:

Execution example:

table_create Logs TABLE_NO_KEY
# [[0, 1337566253.89858, 0.000355720520019531], true]
column_create Logs timestamp COLUMN_SCALAR Time
# [[0, 1337566253.89858, 0.000355720520019531], true]
object_exist Logs.timestamp
# [[0, 1337566253.89858, 0.000355720520019531], true]

Logs is table name and timestamp is column name in Logs.timestamp.

7.3.40.4.2. Optional parameters#

There is no optional parameter.

7.3.40.5. Return value#

The command returns true as body if object with the specified name exists in database such as:

[HEADER, true]

The command returns false otherwise such as:

[HEADER, false]

See Output format for HEADER.