In the previous feature highlight I described how to manually create data tables in Backendless console. In this post I will show how to setup a data table schema. A table schema in Backendless is a collection of table columns. Each column may have the following attributes:
- Column name – identifies the column in the table and becomes a property in the objects saved in the table.
- Data type – determines the type of data which can be stored in the corresponding object property. Available data types are: string (up to 500 characters), text (up to 3000 characters), datetime, integer, double, boolean.
- Default value – when an object is stored and the property does not contain a value, Backendless assigns and stores the specified default value.
- Validator – validates data in the property using either a built-in or custom (regular expression validator).
- Constraints – defines restrictions for the column, such as that it must be unique, contain non-null values, etc.
To access the schema editor tool:
- Login to Backendless console, select your app and click the Data icon.
- Select the table you would like to edit the schema for and click the SCHEMA tab:
- When you are in the schema editor tool, you can inspect the existing table columns or add new ones.
- To add a column, click the New button. You will see the following popup:
- Enter a name for the column and select the data type for the Type field. If you are not sure about the default value or the validator, ignore those fields for now – we will be reviewing them in future posts.
- Click CREATE to create the column.
Schema management includes a lot more tasks than just creating table columns. In the future posts we will be reviewing the following:
- Configuring validators.
- Configuring default values.
- Renaming/deleting columns and relationships.
- Creating relationships with other data tables.
- Creating relationships with Geopoints.
- Creating relationships with Files.
- Configuring constraints.