Package org.eclipse.persistence.queries

Class ValueReadQuery

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable
    public class ValueReadQuery
extends DirectReadQuery

    Purpose: Concrete class to perform a read of a single data value.

    Responsibilities: Used in conjunction with CursoredStream size and Platform getSequence. This can be used to read a single data value (i.e. one field). A single data value is returned, or null if no rows are returned.

    See Also:
    Serialized Form
    Author:
    James Sutherland
    Since:
    TOPLink/Java 1.2

    • Constructor Detail

      • ValueReadQuery

        public ValueReadQuery()
        PUBLIC: Initialize the state of the query.

      • ValueReadQuery

        public ValueReadQuery​(java.lang.String sqlString)
        PUBLIC: Initialize the query to use the specified SQL string. Warning: Allowing an unverified SQL string to be passed into this method makes your application vulnerable to SQL injection attacks.

      • ValueReadQuery

        public ValueReadQuery​(Call call)
        PUBLIC: Initialize the query to use the specified call.

    • Method Detail

      • isValueReadQuery

        public boolean isValueReadQuery()
        PUBLIC: Return if this is a value read query.
        Overrides:
        isValueReadQuery in class DatabaseQuery