The "primaryKey" property is an optional enumerated string that identifies a table's primary key. It defaults to "data".
Note The best practice is not to use the
"primaryKeyFields"or"primaryKey"properties, so the"createTable"action will automatically create a primary key field named"id"with a unique index named"id_pk".
Each table created by the JSON DB API has a primary key that uniquely identifies each record.
"createTable" automatically adds the "id" field as the primary key to your table. It makes "id" an auto-increment bigint field and indexes the field with a unique index named "id_pk". Using the "id" field as the primary key is a best practice.
You can specify one or more fields to be the primary key of the table instead of the "id" field. To do so, you must add the "primaryKeyFields" property to "createTable" or use the "fields" property's "primaryKey" to specify which field(s) are in the primary key.
Note You should not use both the
"primaryKeyFields"and"primaryKey"properties together.
If multiple fields are specified for the key, the index is named "pk". If only one field is specified for the key, the index is named "<fieldname>_pk".
If you use the "primaryKey" property to specify multiple fields as the primary key, the assigned value from 1 to n specifies the order of the fields in the primary key. Assign "primaryKey": 1 to the first field in the primary key, "primaryKey": 2 to the second, and so forth. If you create a primary key with multiple fields, the index is named "pk". If you specify just one field, the index is named "<fieldname>_pk".
Example
"fields": [
{
"name": "a",
"type": "tinyint",
"primaryKey": 1
},
{
"name": "b",
"type": "smallint",
"primaryKey": 2
},
{
"name": "c",
"type": "integer",
"primaryKey": 3
}
]