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 function concat(?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).