Simple expressions

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

Syntax:

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

In addition to the user schema, schema can also be "PUBLIC" with double quotation marks (" "). A "PUBLIC" schema specifies a table or view.

Notice

• PUBLIC can be used as a public synonym only in Data Manipulation Language (DML) statements. In Data Definition Language (DDL) statements, it cannot be used as a public synonym.
• NCHAR and NVARCHAR2 are not valid pseudocolumn data types.

The following examples are valid simple expressions:

• employees.first_name

• 'welcome to OceanBase'

• 10

• 3*3