SQLFunction、SQLFunctionTemplate

public interface SQLFunction

Provides support routines(常规) for the HQL functions as used in the various(各种各样的,不同的) SQL Dialects Provides an interface for supporting various HQL functions that are translated(翻译) to SQL. The Dialect and its sub-classes use this interface to provide details required for processing(处理) of the function.

public class SQLFunctionTemplate

extends Object implements SQLFunction

Represents HQL functions that can have different representations(表现形式) in different SQL dialects. E.g. in HQL we can define functionconcat(?1, ?2)to concatenate(连接) two strings p1 and p2. Target SQL function will be dialect-specific, e.g.(?1 || ?2)for Oracle,concat(?1, ?2)for MySql,(?1 + ?2)for MS SQL. Each dialect will define a template(模板) as a string (exactly like above) marking(标记) function parameters with '?' followed by parameter's index (first index is 1).