SQLFuntion\SQLFuntionTemplate

public interface SQLFunction

Provides support routines常规的for the HQL functions as used in the various不同的SQL Dialects方言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需要for processing处理of the function.

public class SQLFunctionTemplate

extends Object

implements SQLFunction

Represents HQL functions that can have different representations in different SQL dialects. E.g. in HQL we can define functionconcat(?1, ?2)to concatenate连接two strings p1 and p2. Target 规定。。。目标SQL function will be dialect-specific特定, 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标志function parameters参数with '?' followed by parameter's index (first index is 1).