Simple expressions

A simple expression can be a column, a pseudo column, a constant, a sequence number, or a null value.

The syntax of a simple expression is as follows:

{ [ query_name.
  | [schema.]
    { table. | view. | materialized view. }
  ] { column | ROWID }
| ROWNUM
| string
| number
| sequence. { CURRVAL | NEXTVAL }
| NULL
}

In addition to the user schema, the schema can also be specified as "PUBLIC" (with double quotation marks). This is used to specify a table, view, etc.

The following are some examples of simple expressions:

• employees.first_name

• 'welcome to OceanBase'

• 10

• 3*3